You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

690 lines
480 KiB
XML

2 years ago
<?xml version="1.0" encoding="UTF-8"?>
<class-scheme publication-date="2023-02-01" scheme-type="cpc" publication-type="official">
<classification-item breakdown-code="false" not-allocatable="true" level="5" additional-only="false" sort-key="E21B" definition-exists="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>EARTH DRILLING, e.g. DEEP DRILLING </text><reference><text>mining, quarrying <class-ref scheme="cpc">E21C</class-ref>; making shafts, driving galleries or tunnels <class-ref scheme="cpc">E21D</class-ref></text></reference></title-part><title-part><text>OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS</text></title-part></class-title><notes-and-warnings date-revised="2013-01-01"><note type="warning"><note-paragraph warning-type="ipc-not-used">The following IPC groups are not in the CPC scheme. The subject matter for these IPC groups is classified in the following CPC groups: <table><row><entry><class-ref scheme="ipc">E21B7/08</class-ref></entry><entry> covered by </entry><entry><class-ref scheme="cpc">E21B7/06</class-ref></entry></row><row><entry><class-ref scheme="ipc">E21B43/22</class-ref></entry><entry> covered by </entry><entry><class-ref scheme="cpc">C09K8/58</class-ref></entry></row></table></note-paragraph><note-paragraph>In this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="true" level="6" additional-only="false" sort-key="E21B1/00" date-revised="2013-01-01" status="published"><classification-symbol>E21B1/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Methods or apparatus for drilling</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B1/00" definition-exists="true" ipc-concordant="E21B1/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Percussion drilling </text><reference><text>drives used in the borehole <class-ref scheme="cpc">E21B4/00</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="note"><note-paragraph>When classifying in groups <class-ref scheme="cpc">E21B1/12</class-ref> - <class-ref scheme="cpc">E21B1/38</class-ref>, a symbol from one of the following main groups of <class-ref scheme="cpc">B25D</class-ref> should also be given:<subnote type="bullet"><note-paragraph><class-ref scheme="cpc">B25D9/00</class-ref> Portable percussive tools with fluid-pressure drives</note-paragraph><note-paragraph><class-ref scheme="cpc">B25D11/00</class-ref> Portable percussive tools with motor drive</note-paragraph><note-paragraph><class-ref scheme="cpc">B25D16/00</class-ref> Portable percussive machines with superimposed rotation</note-paragraph><note-paragraph><class-ref scheme="cpc">B25D17/00</class-ref> Details of, or accessories for, portable power-driven percussive tools</note-paragraph></subnote></note-paragraph></note><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B1/00</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B1/12</class-ref>, <class-ref scheme="cpc">E21B1/14</class-ref>, <class-ref scheme="cpc">E21B1/16</class-ref>, <class-ref scheme="cpc">E21B1/18</class-ref>, <class-ref scheme="cpc">E21B1/20</class-ref>, <class-ref scheme="cpc">E21B1/22</class-ref>, <class-ref scheme="cpc">E21B1/24</class-ref>, <class-ref scheme="cpc">E21B1/26</class-ref>, <class-ref scheme="cpc">E21B1/28</class-ref>, <class-ref scheme="cpc">E21B1/30</class-ref>, <class-ref scheme="cpc">E21B1/32</class-ref>, <class-ref scheme="cpc">E21B1/34</class-ref>, <class-ref scheme="cpc">E21B1/36</class-ref>, and <class-ref scheme="cpc">E21B1/38</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B1/02" definition-exists="false" ipc-concordant="E21B1/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/02</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Surface drives for drop hammers </text><CPC-specific-text><text>or percussion drilling</text></CPC-specific-text><text>, e.g. with a cable</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B1/02</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B1/12</class-ref>.<br/>Group <class-ref scheme="cpc">E21B1/02</class-ref> is also impacted by reclassification into groups <class-ref scheme="cpc">E21B1/04</class-ref>, <class-ref scheme="cpc">E21B1/36</class-ref> and <class-ref scheme="cpc">E21B1/38</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B1/04" definition-exists="false" ipc-concordant="E21B1/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/04</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Devices for reversing the movement of the rod or cable at the surface</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B1/04</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B1/02</class-ref> and <class-ref scheme="cpc">E21B1/12</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B1/12" definition-exists="false" ipc-concordant="E21B1/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/12</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>with a reciprocating impulse member </text><reference><text><class-ref scheme="cpc">E21B1/02</class-ref>, <class-ref scheme="cpc">E21B1/38</class-ref> take precedence</text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B1/12</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B1/00</class-ref>.<br/>Group <class-ref scheme="cpc">E21B1/12</class-ref> is also impacted by reclassification into groups <class-ref scheme="cpc">E21B1/02</class-ref>, <class-ref scheme="cpc">E21B1/04</class-ref>, <class-ref scheme="cpc">E21B1/14</class-ref>, <class-ref scheme="cpc">E21B1/16</class-ref>, <class-ref scheme="cpc">E21B1/18</class-ref>, <class-ref scheme="cpc">E21B1/20</class-ref>, <class-ref scheme="cpc">E21B1/22</class-ref>, <class-ref scheme="cpc">E21B1/24</class-ref>, <class-ref scheme="cpc">E21B1/26</class-ref>, <class-ref scheme="cpc">E21B1/28</class-ref>, <class-ref scheme="cpc">E21B1/30</class-ref>, <class-ref scheme="cpc">E21B1/32</class-ref>, <class-ref scheme="cpc">E21B1/34</class-ref> and <class-ref scheme="cpc">E21B1/38</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B1/14" definition-exists="false" ipc-concordant="E21B1/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/14</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>driven by a rotating mechanism</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Groups <class-ref scheme="cpc">E21B1/14</class-ref> - <class-ref scheme="cpc">E21B1/20</class-ref> are incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B1/00</class-ref> and <class-ref scheme="cpc">E21B1/12</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B1/16" definition-exists="false" ipc-concordant="E21B1/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/16</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>with spring-mounted reciprocating masses, e.g. with air cushion</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B1/18" definition-exists="false" ipc-concordant="E21B1/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/18</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>with elastic joining of the drive to the push-rod by double buffer springs</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B1/20" definition-exists="false" ipc-concordant="E21B1/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/20</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>formed as centrifugal hammers</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B1/22" definition-exists="false" ipc-concordant="E21B1/22" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/22</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>driven by electromagnets</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B1/22</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B1/00</class-ref> and <class-ref scheme="cpc">E21B1/12</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B1/24" definition-exists="false" ipc-concordant="E21B1/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/24</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>the impulse member being a piston driven directly by fluid pressure</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Groups <class-ref scheme="cpc">E21B1/24</class-ref> - <class-ref scheme="cpc">E21B1/34</class-ref> are incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B1/00</class-ref> and <class-ref scheme="cpc">E21B1/12</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B1/26" definition-exists="false" ipc-concordant="E21B1/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/26</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by liquid pressure</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B1/28" definition-exists="false" ipc-concordant="E21B1/28" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/28</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>working with pulses</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B1/30" definition-exists="false" ipc-concordant="E21B1/30" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/30</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by air, steam or gas pressure</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B1/32" definition-exists="false" ipc-concordant="E21B1/32" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/32</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>working with pulses</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B1/34" definition-exists="false" ipc-concordant="E21B1/34" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/34</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>the impulse member being a piston of an internal-combustion engine</text></title-part></class-title></classification-item></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B1/36" definition-exists="false" ipc-concordant="E21B1/36" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/36</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Tool-carrier piston type, i.e. in which the tool is connected to an impulse member</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B1/36</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B1/00</class-ref>, <class-ref scheme="cpc">E21B1/02</class-ref> and <class-ref scheme="cpc">E21B1/12</class-ref>.<br/> All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B1/38" definition-exists="false" ipc-concordant="E21B1/38" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B1/38</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Hammer piston type, i.e. in which the tool bit or anvil is hit by an impulse member</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B1/38</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B1/00</class-ref>, <class-ref scheme="cpc">E21B1/02</class-ref> and <class-ref scheme="cpc">E21B1/12</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B3/00" definition-exists="true" ipc-concordant="E21B3/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B3/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Rotary drilling </text><reference><text>drives used in the borehole <class-ref scheme="cpc">E21B4/00</class-ref>; rotary drilling machines in general <class-ref scheme="cpc">B23B</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B3/00</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B3/02</class-ref>, <class-ref scheme="cpc">E21B3/022</class-ref>, <class-ref scheme="cpc">E21B3/025</class-ref>, <class-ref scheme="cpc">E21B3/03</class-ref>, <class-ref scheme="cpc">E21B3/035</class-ref>, <class-ref scheme="cpc">E21B3/04</class-ref>, <class-ref scheme="cpc">E21B3/045</class-ref>, and <class-ref scheme="cpc">E21B3/06</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B3/02" definition-exists="false" ipc-concordant="E21B3/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B3/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Surface drives for rotary drilling</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B3/02</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B3/00</class-ref>.<br/>Group <class-ref scheme="cpc">E21B3/02</class-ref> is also impacted by reclassification into group <class-ref scheme="cpc">E21B3/022</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B3/00</class-ref>, <class-ref scheme="cpc">E21B3/02</class-ref>, and <class-ref scheme="cpc">E21B3/022</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B3/022" definition-exists="false" ipc-concordant="E21B3/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B3/022</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Top drives</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B3/022</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B3/00</class-ref> and <class-ref scheme="cpc">E21B3/02</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B3/00</class-ref>, <class-ref scheme="cpc">E21B3/02</class-ref>, and <class-ref scheme="cpc">E21B3/022</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B3/025" definition-exists="false" ipc-concordant="E21B3/025" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B3/025</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with a to-and-fro rotation of the tool</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B3/025</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B3/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B3/00</class-ref> and <class-ref scheme="cpc">E21B3/025</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B3/03" definition-exists="false" ipc-concordant="E21B3/03" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B3/03</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with an intermittent unidirectional rotation of the tool</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B3/03</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B3/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B3/00</class-ref> and <class-ref scheme="cpc">E21B3/03</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B3/035" definition-exists="false" ipc-concordant="E21B3/035" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B3/035</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with slipping or elastic transmission</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B3/035</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B3/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B3/00</class-ref> and <class-ref scheme="cpc">E21B3/035</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B3/04" definition-exists="false" ipc-concordant="E21B3/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B3/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Rotary tables </text><CPC-specific-text><reference><text>portable drilling rigs with rotary tables <class-ref scheme="cpc">E21B7/021</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Groups <class-ref scheme="cpc">E21B3/04</class-ref> &#8211; <class-ref scheme="cpc">E21B3/06</class-ref> are incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B3/00</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B3/045" definition-exists="true" ipc-concordant="E21B3/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B3/045</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>movably mounted on the drilling structure or platform </text><reference><text>derricks adapted to be moved on their substructure <class-ref scheme="cpc">E21B15/003</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B3/06" definition-exists="false" ipc-concordant="E21B3/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B3/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Adaptation of rotary draw works to drive rotary tables </text><reference><text>connecting or disconnecting couplings or joints <class-ref scheme="cpc">E21B19/16</class-ref>; rope, cable, or chain winding mechanisms, capstans <class-ref scheme="cpc">B66D</class-ref></text></reference></title-part></class-title></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B4/00" definition-exists="true" ipc-concordant="E21B4/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B4/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Drives for drilling, used in the borehole</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B4/003" definition-exists="true" ipc-concordant="E21B4/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B4/003</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Bearing, sealing, lubricating details </text><reference><text>for roller bits <class-ref scheme="cpc">E21B10/22</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B4/006" definition-exists="true" ipc-concordant="E21B4/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B4/006</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Mechanical motion converting means, e.g. reduction gearings </text><reference><text><class-ref scheme="cpc">E21B4/10</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B4/02" definition-exists="false" ipc-concordant="E21B4/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Fluid rotary type drives </text><reference><text>hydraulic turbines for drilling wells <class-ref scheme="cpc">F03B13/02</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B4/04" definition-exists="false" ipc-concordant="E21B4/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Electric drives </text><reference><text><class-ref scheme="cpc">E21B4/12</class-ref> takes precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B4/06" definition-exists="true" ipc-concordant="E21B4/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Down-hole impacting means, e.g. hammers </text><reference><text>percussion drill bits <class-ref scheme="cpc">E21B10/36</class-ref>; boring rams <class-ref scheme="cpc">E21B11/02</class-ref>; releasing-jars <class-ref scheme="cpc">E21B31/107</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B4/08" definition-exists="false" ipc-concordant="E21B4/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>impact being obtained by gravity only, e.g. with lost-motion connection</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B4/10" definition-exists="false" ipc-concordant="E21B4/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>continuous unidirectional rotary motion of shaft or drilling pipe effecting consecutive impacts</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B4/12" definition-exists="false" ipc-concordant="E21B4/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/12</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Electrically operated hammers</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B4/14" definition-exists="false" ipc-concordant="E21B4/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/14</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Fluid operated hammers</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B4/145" definition-exists="false" ipc-concordant="E21B4/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/145</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>of the self propelled-type, e.g. with a reverse mode to retract the device from the hole</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B4/16" definition-exists="false" ipc-concordant="E21B4/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/16</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Plural down-hole drives, e.g. for combined percussion and rotary drilling </text><reference><text><class-ref scheme="cpc">E21B4/10</class-ref> takes precedence</text></reference></title-part><title-part><text>Drives for multi-bit drilling units</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B4/18" definition-exists="false" ipc-concordant="E21B4/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/18</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Anchoring or feeding in the borehole</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B4/20" definition-exists="false" ipc-concordant="E21B4/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B4/20</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>combined with surface drive </text><reference><text><class-ref scheme="cpc">E21B4/10</class-ref> takes precedence</text></reference></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B6/00" definition-exists="true" ipc-concordant="E21B6/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B6/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Drives for drilling with combined rotary and percussive action </text><reference><text>drives used in the borehole <class-ref scheme="cpc">E21B4/00</class-ref>; portable percussive machines with superimposed rotation <class-ref scheme="cpc">B25D16/00</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B6/02" definition-exists="false" ipc-concordant="E21B6/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B6/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>the rotation being continuous</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B6/04" definition-exists="false" ipc-concordant="E21B6/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B6/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Separate drives for percussion and rotation</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B6/06" definition-exists="false" ipc-concordant="E21B6/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-01-01" status="published"><classification-symbol>E21B6/06</classification-symbol><class-title date-revised="2017-01-01"><title-part><text>the rotation being intermittent, e.g. obtained by ratchet device</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B6/08" definition-exists="false" ipc-concordant="E21B6/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B6/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Separate drives for percussion and rotation</text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B7/00" definition-exists="true" ipc-concordant="E21B7/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Special methods or apparatus for drilling</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/001" definition-exists="false" ipc-concordant="E21B7/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/001</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Drilling a non circular hole </text><reference><text>excavating trenches <class-ref scheme="cpc">E02F5/02</class-ref>; cutting machines for slitting <class-ref scheme="cpc">E21C25/00</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/002" definition-exists="false" ipc-concordant="E21B7/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/002</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Drilling with diversely driven shafts extending into the borehole </text><reference><text>simultaneously drilling and casing <class-ref scheme="cpc">E21B7/20</class-ref>; plural down-hole drives <class-ref scheme="cpc">E21B4/16</class-ref>; <class-ref scheme="cpc">E21B7/001</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/003" definition-exists="false" ipc-concordant="E21B7/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/003</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Drilling with mechanical conveying means </text><reference><text>tunnelling <class-ref scheme="cpc">E21D</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/005" definition-exists="false" ipc-concordant="E21B7/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/005</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with helical conveying means </text><reference><text><class-ref scheme="cpc">E21B7/201</class-ref> takes precedence; augers <class-ref scheme="cpc">E21B10/44</class-ref>; drilling rods or pipes with helical structure <class-ref scheme="cpc">E21B17/22</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/006" definition-exists="true" ipc-concordant="E21B7/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/006</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>combined with a bucket-type container</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/007" definition-exists="true" ipc-concordant="E21B7/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/007</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Drilling by use of explosives </text><reference><text>underwater drilling using explosives <class-ref scheme="cpc">E21B7/1245</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/008" definition-exists="false" ipc-concordant="E21B7/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/008</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Drilling ice or a formation covered by ice</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/02" definition-exists="false" ipc-concordant="E21B7/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/02</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Drilling rigs characterized by means for land transport </text><CPC-specific-text><text>with their own drive</text></CPC-specific-text><text>, e.g. skid mounting or wheel mounting </text><reference><text>portable drilling rigs for use on underwater floors <class-ref scheme="cpc">E21B7/124</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/021" definition-exists="true" ipc-concordant="E21B7/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/021</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>With a rotary table, i.e. a fixed rotary drive for a relatively advancing tool</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/022" definition-exists="false" ipc-concordant="E21B7/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/022</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Control of the drilling operation; Hydraulic or pneumatic means for activation or operation </text><reference><text>control circuits for drilling masts <class-ref scheme="cpc">E21B15/045</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/023" definition-exists="false" ipc-concordant="E21B7/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/023</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the mast being foldable or telescopically retractable</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/024" definition-exists="false" ipc-concordant="E21B7/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/024</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>having means for adapting to inclined terrain; having means for stabilizing the vehicle while drilling</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/025" definition-exists="false" ipc-concordant="E21B7/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/025</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Rock drills, i.e. jumbo drills</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/026" definition-exists="false" ipc-concordant="E21B7/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/026</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>having auxiliary platforms, e.g. for observation purposes</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/027" definition-exists="false" ipc-concordant="E21B7/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/027</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Drills for drilling shallow holes, e.g. for taking soil samples or for drilling postholes</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/028" definition-exists="false" ipc-concordant="E21B7/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/028</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the drilling apparatus being detachable from the vehicle, e.g. hand portable drills</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B7/028</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B11/005</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B11/005</class-ref> and <class-ref scheme="cpc">E21B7/028</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/04" definition-exists="true" ipc-concordant="E21B7/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/04</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Directional drilling </text><CPC-specific-text><reference><text>derricks or masts specially adapted therefor <class-ref scheme="cpc">E21B15/04</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/043" definition-exists="false" ipc-concordant="E21B7/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/043</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>for underwater installations</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/046" definition-exists="false" ipc-concordant="E21B7/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/046</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>horizontal drilling </text><reference><text>drilling with mechanical conveying means <class-ref scheme="cpc">E21B7/003</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/06" definition-exists="true" ipc-concordant="E21B7/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/06</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Deflecting the direction of boreholes</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/061" definition-exists="false" ipc-concordant="E21B7/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/061</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the tool shaft advancing relative to a guide, e.g. a curved tube or a whipstock</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/062" definition-exists="false" ipc-concordant="E21B7/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/062</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the tool shaft rotating inside a non-rotating guide travelling with the shaft </text><reference><text><class-ref scheme="cpc">E21B7/067</class-ref> and <class-ref scheme="cpc">E21B7/068</class-ref> take precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/064" definition-exists="false" ipc-concordant="E21B7/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/064</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>specially adapted drill bits therefor</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/065" definition-exists="false" ipc-concordant="E21B7/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/065</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using oriented fluid jets</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/067" definition-exists="false" ipc-concordant="E21B7/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/067</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/068" definition-exists="false" ipc-concordant="E21B7/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/068</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>drilled by a down-hole drilling motor </text><reference><text>down-hole drives <u>per se</u> <class-ref scheme="cpc">E21B4/00</class-ref>, <class-ref scheme="cpc">E21B7/067</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/10" definition-exists="false" ipc-concordant="E21B7/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Correction of deflected boreholes</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/12" definition-exists="false" ipc-concordant="E21B7/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/12</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Underwater drilling </text><reference><CPC-specific-text><text>derricks or masts specially adapted therefor <class-ref scheme="cpc">E21B15/02</class-ref>;</text></CPC-specific-text><text> telescoping joints <class-ref scheme="cpc">E21B17/07</class-ref>; using heave compensators <class-ref scheme="cpc">E21B19/09</class-ref>; well heads specially adapted for underwater installations <class-ref scheme="cpc">E21B33/035</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/122" definition-exists="false" ipc-concordant="E21B7/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/122</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with submersible vertically movable guide</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/124" definition-exists="false" ipc-concordant="E21B7/124" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/124</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with underwater tool drive prime mover, e.g. portable drilling rigs for use on underwater floors</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/1245" definition-exists="false" ipc-concordant="E21B7/124" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-08-01" status="published"><classification-symbol>E21B7/1245</classification-symbol><class-title date-revised="2017-08-01"><title-part><CPC-specific-text><text>using explosive means </text><reference><text>anchors driven in by explosive charges <class-ref scheme="cpc">B63B21/28</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/128" definition-exists="true" ipc-concordant="E21B7/128" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/128</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>from floating support with independent underwater anchored guide base</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/132" definition-exists="false" ipc-concordant="E21B7/132" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/132</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>from underwater buoyant support</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/136" definition-exists="false" ipc-concordant="E21B7/136" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/136</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>from non-buoyant support </text><reference><text><class-ref scheme="cpc">E21B7/124</class-ref> takes precedence</text></reference></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/14" definition-exists="true" ipc-concordant="E21B7/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/14</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Drilling by use of heat, e.g. flame drilling</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/143" definition-exists="false" ipc-concordant="E21B7/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/143</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>underwater</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/146" definition-exists="false" ipc-concordant="E21B7/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/146</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Thermal lances</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/15" definition-exists="false" ipc-concordant="E21B7/15" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/15</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>of electrically generated heat</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/16" definition-exists="false" ipc-concordant="E21B7/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/16</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Applying separate balls or pellets by the pressure of the drill, so-called shot-drilling</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/18" definition-exists="true" ipc-concordant="E21B7/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/18</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Drilling by liquid or gas jets, with or without entrained pellets </text><reference><text><class-ref scheme="cpc">E21B7/14</class-ref> takes precedence; hydraulic monitors <class-ref scheme="cpc">E21C45/00</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/185" definition-exists="false" ipc-concordant="E21B7/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/185</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>underwater</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/20" definition-exists="true" ipc-concordant="E21B7/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/20</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Driving or forcing casings or pipes into boreholes, e.g. sinking</text></title-part><title-part><text>Simultaneously drilling and casing boreholes </text><reference><text>surface means for applying to-and-fro rotation movements to the casing <class-ref scheme="cpc">E21B3/025</class-ref>; placing piles <class-ref scheme="cpc">E02D7/00</class-ref>; sinking shafts while moving the lining downwards <class-ref scheme="cpc">E21D1/08</class-ref> </text><CPC-specific-text><text>; making galleries by forcing prefabricated elements through the ground <class-ref scheme="cpc">E21D9/005</class-ref></text></CPC-specific-text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/201" definition-exists="true" ipc-concordant="E21B7/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/201</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>with helical conveying means</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/203" definition-exists="true" ipc-concordant="E21B7/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/203</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using down-hole drives</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/205" definition-exists="false" ipc-concordant="E21B7/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/205</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>without earth removal </text><reference><text><class-ref scheme="cpc">E21B7/30</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings date-revised="2013-01-01"><note type="note"><note-paragraph>Special methods or apparatus for drilling without earth removal <class-ref scheme="cpc">E21B7/26</class-ref></note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B7/206" definition-exists="true" ipc-concordant="E21B7/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/206</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using down-hole drives</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/208" definition-exists="true" ipc-concordant="E21B7/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/208</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using down-hole drives </text><reference><text><class-ref scheme="cpc">E21B7/203</class-ref> and <class-ref scheme="cpc">E21B7/206</class-ref> take precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/24" definition-exists="false" ipc-concordant="E21B7/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/24</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Drilling using vibrating or oscillating means, e.g. out-of-balance masses </text><reference><text>percussion drilling <class-ref scheme="cpc">E21B1/00</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/26" definition-exists="false" ipc-concordant="E21B7/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/26</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Drilling without earth removal, e.g. with self-propelled burrowing devices </text><reference><text><class-ref scheme="cpc">E21B7/30</class-ref> takes precedence; down-hole drives <class-ref scheme="cpc">E21B4/00</class-ref> </text><CPC-specific-text><text>, e.g. self-propelled fluid-operated hammers <class-ref scheme="cpc">E21B4/145</class-ref></text></CPC-specific-text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B7/26</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B7/267</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B7/26</class-ref> and <class-ref scheme="cpc">E21B7/267</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/265" definition-exists="false" ipc-concordant="E21B7/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/265</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Combined with earth removal</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B7/265</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B7/267</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B7/265</class-ref> and <class-ref scheme="cpc">E21B7/267</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/267" definition-exists="false" ipc-concordant="E21B7/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B7/267</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Drilling devices with senders, e.g. radio-transmitters for position of drilling tool</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B7/267</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B7/26</class-ref> and <class-ref scheme="cpc">E21B7/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B7/26</class-ref>, <class-ref scheme="cpc">E21B7/265</class-ref>, and <class-ref scheme="cpc">E21B7/267</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B7/28" definition-exists="true" ipc-concordant="E21B7/28" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/28</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Enlarging drilled holes, e.g. by counterboring </text><reference><text>drill bits for enlarging the borehole <class-ref scheme="cpc">E21B10/26</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B7/30" definition-exists="false" ipc-concordant="E21B7/30" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B7/30</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>without earth removal</text></title-part></class-title></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="true" level="6" additional-only="false" sort-key="E21B10/00" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Drilling tools</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B10/00" definition-exists="true" ipc-concordant="E21B10/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Drill bits </text><reference><text>specially adapted for deflecting the direction of boring <class-ref scheme="cpc">E21B7/064</class-ref>; with means for collecting substances <class-ref scheme="cpc">E21B27/00</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/003" definition-exists="false" ipc-concordant="E21B10/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/003</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with cutting edges facing in opposite axial directions</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/006" definition-exists="false" ipc-concordant="E21B10/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/006</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>providing a cutting edge which is self-renewable during drilling</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/02" definition-exists="true" ipc-concordant="E21B10/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Core bits </text><reference><text>characterised by wear resisting parts <class-ref scheme="cpc">E21B10/46</class-ref>; obtaining undisturbed cores <class-ref scheme="cpc">E21B25/00</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/04" definition-exists="false" ipc-concordant="E21B10/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with core destroying means</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/06" definition-exists="false" ipc-concordant="E21B10/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Roller core bits</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/08" definition-exists="false" ipc-concordant="E21B10/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Roller bits </text><reference><text>roller core bits <class-ref scheme="cpc">E21B10/06</class-ref>; with leading portion <class-ref scheme="cpc">E21B10/26</class-ref>; characterised by wear resisting parts <class-ref scheme="cpc">E21B10/46</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/083" definition-exists="false" ipc-concordant="E21B10/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/083</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with longitudinal axis, e.g. wobbling or nutating roller bit </text><reference><text>longitudinal axis roller reamers <class-ref scheme="cpc">E21B10/30</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/086" definition-exists="false" ipc-concordant="E21B10/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/086</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with excentric movement</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/10" definition-exists="false" ipc-concordant="E21B10/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with roller axle supported at both ends </text><reference><text>with disc-cutters <class-ref scheme="cpc">E21B10/12</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/12" definition-exists="false" ipc-concordant="E21B10/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/12</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with discs cutters</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/14" definition-exists="false" ipc-concordant="E21B10/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/14</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>combined with non-rolling cutters other than of leading-portion type</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/16" definition-exists="false" ipc-concordant="E21B10/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/16</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by tooth form or arrangement</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/18" definition-exists="false" ipc-concordant="E21B10/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/18</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by conduits or nozzles for drilling fluids </text><reference><text>drilling fluid supply to the bearings <class-ref scheme="cpc">E21B10/23</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/20" definition-exists="false" ipc-concordant="E21B10/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/20</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by detachable or adjustable parts, e.g. legs or axles </text><reference><text>cross axle roller bits <class-ref scheme="cpc">E21B10/10</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/22" definition-exists="false" ipc-concordant="E21B10/22" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/22</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by bearing, lubrication or sealing details</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/23" definition-exists="false" ipc-concordant="E21B10/23" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/23</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with drilling fluid supply to the bearings</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/24" definition-exists="false" ipc-concordant="E21B10/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/24</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by lubricating details</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B10/246" definition-exists="false" ipc-concordant="E21B10/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/246</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with pumping means for feeding lubricant</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/25" definition-exists="false" ipc-concordant="E21B10/25" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/25</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by sealing details</text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/26" definition-exists="false" ipc-concordant="E21B10/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/26</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Drill bits with leading portion, i.e. drill bits with a pilot cutter</text></title-part><title-part><text>Drill bits for enlarging the borehole, e.g. reamers </text><reference><text>percussion drill bits with leading portion <class-ref scheme="cpc">E21B10/40</class-ref>; augers with leading portion <class-ref scheme="cpc">E21B10/44</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/26</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/26</class-ref> and <class-ref scheme="cpc">E21B10/265</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/265" definition-exists="false" ipc-concordant="E21B10/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/265</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Bi-center drill bits, i.e. an integral bit and eccentric reamer used to simultaneously drill and underream the hole</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B10/265</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B10/26</class-ref>, <class-ref scheme="cpc">E21B10/28</class-ref>, <class-ref scheme="cpc">E21B10/30</class-ref>, <class-ref scheme="cpc">E21B10/32</class-ref>, <class-ref scheme="cpc">E21B10/322</class-ref>, <class-ref scheme="cpc">E21B10/325</class-ref>, <class-ref scheme="cpc">E21B10/327</class-ref>, <class-ref scheme="cpc">E21B10/34</class-ref>, and <class-ref scheme="cpc">E21B10/345</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/28" definition-exists="false" ipc-concordant="E21B10/28" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/28</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with non-expansible roller cutters</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/28</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/28</class-ref> and <class-ref scheme="cpc">E21B10/265</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/30" definition-exists="false" ipc-concordant="E21B10/30" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/30</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Longitudinal axis roller reamers, e.g. reamer stabilisers</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/30</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/30</class-ref> and <class-ref scheme="cpc">E21B10/265</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/32" definition-exists="false" ipc-concordant="E21B10/32" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/32</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with expansible cutting tools</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/32</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/32</class-ref> and <class-ref scheme="cpc">E21B10/265</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/322" definition-exists="false" ipc-concordant="E21B10/32" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/322</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>cutter shifted by fluid pressure </text><reference><text><class-ref scheme="cpc">E21B10/345</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/322</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/322</class-ref> and <class-ref scheme="cpc">E21B10/265</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/325" definition-exists="false" ipc-concordant="E21B10/32" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/325</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the cutter being shifted by a spring mechanism</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/325</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/325</class-ref> and <class-ref scheme="cpc">E21B10/265</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/327" definition-exists="false" ipc-concordant="E21B10/32" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/327</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the cutter being pivoted about a longitudinal axis </text><reference><text><class-ref scheme="cpc">E21B10/34</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/327</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/327</class-ref> and <class-ref scheme="cpc">E21B10/265</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/34" definition-exists="false" ipc-concordant="E21B10/34" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/34</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>of roller-cutter type</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/34</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/34</class-ref> and <class-ref scheme="cpc">E21B10/265</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B10/345" definition-exists="false" ipc-concordant="E21B10/34" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/345</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>cutter shifted by fluid pressure</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/345</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/265</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/345</class-ref> and <class-ref scheme="cpc">E21B10/265</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/36" definition-exists="false" ipc-concordant="E21B10/36" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/36</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Percussion drill bits </text><reference><CPC-specific-text><text>with helical conveying portion <class-ref scheme="cpc">E21B10/445</class-ref>;</text></CPC-specific-text><text> characterised by wear resisting parts <class-ref scheme="cpc">E21B10/46</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/38" definition-exists="false" ipc-concordant="E21B10/38" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/38</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by conduits or nozzles for drilling fluids</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/40" definition-exists="false" ipc-concordant="E21B10/40" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/40</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with leading portion</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/42" definition-exists="false" ipc-concordant="E21B10/42" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/42</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits </text><reference><text>characterised by wear resisting parts </text><CPC-specific-text><text><class-ref scheme="cpc">E21B10/54</class-ref></text></CPC-specific-text><text>; by conduits or nozzles for drilling fluid <class-ref scheme="cpc">E21B10/60</class-ref>; by detachable or adjustable parts <class-ref scheme="cpc">E21B10/62</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/42</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B10/62</class-ref>, <class-ref scheme="cpc">E21B10/627</class-ref>, and <class-ref scheme="cpc">E21B10/633</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/43" definition-exists="false" ipc-concordant="E21B10/43" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/43</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by the arrangement of teeth or other cutting elements</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/43</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B10/62</class-ref>, <class-ref scheme="cpc">E21B10/627</class-ref>, and <class-ref scheme="cpc">E21B10/633</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/44" definition-exists="false" ipc-concordant="E21B10/44" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/44</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Bits with helical conveying portion, e.g. screw type bits</text></title-part><title-part><text>Augers with leading portion or with detachable parts </text><reference><text><class-ref scheme="cpc">E21B10/42</class-ref> takes precedence; drilling rods with helical structure <class-ref scheme="cpc">E21B17/22</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/445" definition-exists="true" ipc-concordant="E21B10/44" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/445</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>percussion type, e.g. for masonry</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/46" definition-exists="true" ipc-concordant="E21B10/46" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/46</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>characterised by wear resisting parts, e.g. diamond inserts</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/48" definition-exists="true" ipc-concordant="E21B10/48" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/48</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>the bit being of core type</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/485" definition-exists="false" ipc-concordant="E21B10/48" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/485</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with inserts in form of chisels, blades or the like</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/50" definition-exists="false" ipc-concordant="E21B10/50" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/50</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>the bit being of roller type</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/52" definition-exists="false" ipc-concordant="E21B10/52" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/52</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>with chisel- or button-type inserts</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/54" definition-exists="false" ipc-concordant="E21B10/54" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/54</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>the bit being of the rotary drag type, e.g. fork-type bits</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/55" definition-exists="true" ipc-concordant="E21B10/55" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/55</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>with preformed cutting elements </text><reference><text>inserts <u>per se</u> <class-ref scheme="cpc">E21B10/56</class-ref>, <class-ref scheme="cpc">E21B10/58</class-ref></text></reference></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/56" definition-exists="false" ipc-concordant="E21B10/56" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/56</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Button-type inserts </text><reference><text><class-ref scheme="cpc">E21B10/52</class-ref> takes precedence</text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/567" definition-exists="false" ipc-concordant="E21B10/567" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/567</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/567</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/5671</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/567</class-ref> and <class-ref scheme="cpc">E21B10/5671</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B10/5671" definition-exists="false" ipc-concordant="E21B10/567" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/5671</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>with chip breaking arrangements</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B10/5671</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B10/567</class-ref> and <class-ref scheme="cpc">E21B10/5673</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/567</class-ref>, <class-ref scheme="cpc">E21B10/5673</class-ref>, and <class-ref scheme="cpc">E21B10/5671</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B10/5673" definition-exists="false" ipc-concordant="E21B10/567" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/5673</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>having a non planar or non circular cutting face</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B10/5673</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B10/5671</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B10/5673</class-ref> and <class-ref scheme="cpc">E21B10/5671</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B10/5676" definition-exists="false" ipc-concordant="E21B10/567" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/5676</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>having a cutting face with different segments, e.g. mosaic-type inserts</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B10/573" definition-exists="false" ipc-concordant="E21B10/573" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/573</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>characterised by support details, e.g. the substrate construction or the interface between the substrate and the cutting element</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B10/5735" definition-exists="false" ipc-concordant="E21B10/573" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/5735</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Interface between the substrate and the cutting element</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/58" definition-exists="false" ipc-concordant="E21B10/58" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/58</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Chisel-type inserts </text><reference><CPC-specific-text><text><class-ref scheme="cpc">E21B10/485</class-ref>,</text></CPC-specific-text><text> <class-ref scheme="cpc">E21B10/52</class-ref>, <class-ref scheme="cpc">E21B10/54</class-ref> take precedence</text></reference></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/60" definition-exists="true" ipc-concordant="E21B10/60" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/60</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>characterised by conduits or nozzles for drilling fluids </text><reference><text>for roller bits <class-ref scheme="cpc">E21B10/18</class-ref>; for percussion drill bits <class-ref scheme="cpc">E21B10/38</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/602" definition-exists="false" ipc-concordant="E21B10/60" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/602</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the bit being a rotary drag type bit with blades</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/605" definition-exists="false" ipc-concordant="E21B10/60" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/605</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the bit being a core-bit</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/61" definition-exists="false" ipc-concordant="E21B10/61" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/61</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by the nozzle structure</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/62" definition-exists="true" ipc-concordant="E21B10/62" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B10/62</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>characterised by parts, e.g. cutting elements, which are detachable or adjustable </text><reference><text><class-ref scheme="cpc">E21B10/64</class-ref> takes precedence; for roller bits <class-ref scheme="cpc">E21B10/20</class-ref>; for augers <class-ref scheme="cpc">E21B10/44</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Groups <class-ref scheme="cpc">E21B10/62</class-ref> - <class-ref scheme="cpc">E21B10/633</class-ref> are incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B10/42</class-ref> and <class-ref scheme="cpc">E21B10/43</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/627" definition-exists="false" ipc-concordant="E21B10/627" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/627</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with plural detachable cutting elements</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B10/633" definition-exists="false" ipc-concordant="E21B10/633" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/633</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>independently detachable</text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B10/64" definition-exists="true" ipc-concordant="E21B10/64" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/64</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by the whole or part thereof being insertable into or removable from the borehole without withdrawing the drilling pipe </text><reference><text>retrievable core receivers <class-ref scheme="cpc">E21B25/02</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B10/66" definition-exists="false" ipc-concordant="E21B10/66" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B10/66</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>the cutting element movable through the drilling pipe and laterally shiftable</text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B11/00" definition-exists="true" ipc-concordant="E21B11/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B11/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Other drilling tools</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B11/00</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B11/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B11/00</class-ref> and <class-ref scheme="cpc">E21B11/04</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B11/005" definition-exists="false" ipc-concordant="E21B11/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B11/005</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Hand operated drilling tools </text><reference><text>hand portable tools detachable from portable drilling rigs <class-ref scheme="cpc">E21B7/028</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B11/005</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B7/028</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B11/005</class-ref> and <class-ref scheme="cpc">E21B7/028</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B11/02" definition-exists="false" ipc-concordant="E21B11/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B11/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Boring rams </text><reference><text>percussion drives used in the borehole <class-ref scheme="cpc">E21B4/06</class-ref>; percussion drill bits <class-ref scheme="cpc">E21B10/36</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B11/04" definition-exists="false" ipc-concordant="E21B11/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B11/04</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Boring grabs</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B11/04</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B11/00</class-ref> and <class-ref scheme="cpc">E21B27/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B11/00</class-ref>, <class-ref scheme="cpc">E21B27/00</class-ref>, and <class-ref scheme="cpc">E21B11/04</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B11/06" definition-exists="false" ipc-concordant="E21B11/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B11/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with driven cutting chains or similarly driven tools</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B12/00" definition-exists="true" ipc-concordant="E21B12/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B12/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Accessories for drilling tools</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B12/02" definition-exists="false" ipc-concordant="E21B12/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B12/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Wear indicators</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B12/04" definition-exists="false" ipc-concordant="E21B12/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B12/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Drill bit protectors</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B12/06" definition-exists="false" ipc-concordant="E21B12/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B12/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Mechanical cleaning devices</text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="true" level="6" additional-only="false" sort-key="E21B15/00" date-revised="2013-01-01" status="published"><classification-symbol>E21B15/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Other equipment or details for drilling</text></title-part><title-part><text>Well equipment or well maintenance</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B15/00" definition-exists="true" ipc-concordant="E21B15/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B15/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Supports for the drilling machine, e.g. derricks or masts</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B15/003" definition-exists="true" ipc-concordant="E21B15/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B15/003</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>adapted to be moved on their substructure, e.g. with skidding means; adapted to drill a plurality of wells</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B15/006" definition-exists="false" ipc-concordant="E21B15/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B15/006</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Means for anchoring the drilling machine to the ground</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B15/02" definition-exists="true" ipc-concordant="E21B15/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B15/02</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>specially adapted for underwater drilling </text><reference><text><class-ref scheme="cpc">E21B15/04</class-ref> takes precedence; floating drilling platforms <class-ref scheme="cpc">B63B35/44</class-ref>; drilling platforms on legs <class-ref scheme="cpc">E02B17/00</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B15/04" definition-exists="true" ipc-concordant="E21B15/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B15/04</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>specially adapted for directional drilling, e.g. slant hole rigs</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B15/045" definition-exists="false" ipc-concordant="E21B15/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B15/045</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Hydraulic, pneumatic or electric circuits for their positioning</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B17/00" definition-exists="true" ipc-concordant="E21B17/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Drilling rods or pipes</text></title-part><title-part><text>Flexible drill strings</text></title-part><title-part><text>Kellies</text></title-part><title-part><text>Drill collars</text></title-part><title-part><text>Sucker rods</text></title-part><title-part><CPC-specific-text><text>Cables;</text></CPC-specific-text><text> Casings</text></title-part><title-part><text>Tubings </text><reference><text>rod couplings in general <class-ref scheme="cpc">F16D</class-ref>; tubes or tube couplings in general <class-ref scheme="cpc">F16L</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/003" definition-exists="false" ipc-concordant="E21B17/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/003</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with electrically conducting or insulating means </text><reference><text><class-ref scheme="cpc">E21B17/028</class-ref> and <class-ref scheme="cpc">E21B17/023</class-ref> take precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/006" definition-exists="false" ipc-concordant="E21B17/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/006</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Accessories for drilling pipes, e.g. cleaners </text><reference><text>wear protectors <class-ref scheme="cpc">E21B17/10</class-ref>; handling drilling pipes <class-ref scheme="cpc">E21B19/00</class-ref>; thread protectors <class-ref scheme="cpc">B65D59/00</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/01" definition-exists="false" ipc-concordant="E21B17/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/01</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Risers </text><reference><CPC-specific-text><text>supporting a riser from a drilling or production platform <class-ref scheme="cpc">E21B19/004</class-ref>;</text></CPC-specific-text><text> riser connectors </text><CPC-specific-text><text>on well heads</text></CPC-specific-text><text> <class-ref scheme="cpc">E21B33/038</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/012" definition-exists="false" ipc-concordant="E21B17/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/012</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with buoyancy elements </text><reference><text><class-ref scheme="cpc">E21B17/015</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/015" definition-exists="false" ipc-concordant="E21B17/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/015</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Non-vertical risers, e.g. articulated or catenary-type</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/017" definition-exists="false" ipc-concordant="E21B17/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/017</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Bend restrictors for limiting stress on risers</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/02" definition-exists="false" ipc-concordant="E21B17/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/02</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>Couplings</text></title-part><title-part><text>joints </text><CPC-specific-text><reference><text>expandable couplings or joints <class-ref scheme="cpc">E21B43/106</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B17/02</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B17/041</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/02</class-ref> and <class-ref scheme="cpc">E21B17/041</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/021" definition-exists="true" ipc-concordant="E21B17/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/021</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Devices for subsurface connecting or disconnecting by rotation</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/023" definition-exists="false" ipc-concordant="E21B17/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/023</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Arrangements for connecting cables or wirelines to downhole devices</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/025" definition-exists="false" ipc-concordant="E21B17/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/025</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Side entry subs</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/026" definition-exists="true" ipc-concordant="E21B17/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/026</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Arrangements for fixing cables or wirelines to the outside of downhole devices</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/028" definition-exists="false" ipc-concordant="E21B17/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/028</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Electrical or electro-magnetic connections</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B17/028</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B17/0283</class-ref> and <class-ref scheme="cpc">E21B17/0285</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/028</class-ref>, <class-ref scheme="cpc">E21B17/0283</class-ref>, and <class-ref scheme="cpc">E21B17/0285</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/0283" definition-exists="false" ipc-concordant="E21B17/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/0283</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>characterised by the coupling being contactless, e.g. inductive</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B17/0283</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B17/028</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/028</class-ref> and <class-ref scheme="cpc">E21B17/0283</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/0285" definition-exists="false" ipc-concordant="E21B17/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/0285</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>characterised by electrically insulating elements</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B17/0285</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B17/028</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/028</class-ref> and <class-ref scheme="cpc">E21B17/0285</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/03" definition-exists="false" ipc-concordant="E21B17/03" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/03</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>between drilling rod or pipe and drill motor </text><CPC-specific-text><text>or surface drive</text></CPC-specific-text><text>, e.g. between drilling rod and hammer</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/04" definition-exists="false" ipc-concordant="E21B17/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>between rod </text><CPC-specific-text><text>or the like</text></CPC-specific-text><text> and bit or between rod and rod </text><CPC-specific-text><text>or the like</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B17/04</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B17/041</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/04</class-ref> and <class-ref scheme="cpc">E21B17/041</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/041" definition-exists="false" ipc-concordant="E21B17/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/041</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>specially adapted for coiled tubing</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B17/041</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B17/02</class-ref> and <class-ref scheme="cpc">E21B17/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/02</class-ref>, <class-ref scheme="cpc">E21B17/04</class-ref>, and <class-ref scheme="cpc">E21B17/041</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/042" definition-exists="true" ipc-concordant="E21B17/042" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/042</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Threaded</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B17/0423" definition-exists="false" ipc-concordant="E21B17/042" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/0423</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with plural threaded sections, e.g. with two-step threads</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B17/0426" definition-exists="false" ipc-concordant="E21B17/042" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/0426</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with a threaded cylindrical portion, e.g. for percussion rods</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B17/043" definition-exists="false" ipc-concordant="E21B17/043" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/043</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with locking means</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/046" definition-exists="false" ipc-concordant="E21B17/046" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/046</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>with ribs, pins, or jaws, and complementary grooves or the like, e.g. bayonet catches</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B17/046</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B17/0465</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/046</class-ref> and <class-ref scheme="cpc">E21B17/0465</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B17/0465" definition-exists="false" ipc-concordant="E21B17/046" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/0465</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>characterised by radially inserted locking elements</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B17/0465</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B17/046</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/046</class-ref> and <class-ref scheme="cpc">E21B17/0465</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/05" definition-exists="false" ipc-concordant="E21B17/05" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/05</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Swivel joints</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/06" definition-exists="false" ipc-concordant="E21B17/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Releasing-joints, e.g. safety joints</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/07" definition-exists="true" ipc-concordant="E21B17/07" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/07</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Telescoping joints for varying drill string lengths</text></title-part><title-part><text>Shock absorbers </text><reference><text>heave compensators in the derrick <class-ref scheme="cpc">E21B19/09</class-ref>; releasing-jars <class-ref scheme="cpc">E21B31/107</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B17/073" definition-exists="false" ipc-concordant="E21B17/07" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/073</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with axial rotation</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B17/076" definition-exists="false" ipc-concordant="E21B17/07" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/076</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>between rod or pipe and drill bit</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/08" definition-exists="false" ipc-concordant="E21B17/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Casing joints</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/085" definition-exists="false" ipc-concordant="E21B17/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/085</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Riser connections </text><reference><text>connectors for wellhead <class-ref scheme="cpc">E21B33/038</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B17/085</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B17/0853</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/085</class-ref> and <class-ref scheme="cpc">E21B17/0853</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B17/0853" definition-exists="false" ipc-concordant="E21B17/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/0853</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Connections between sections of riser provided with auxiliary lines, e.g. kill and choke lines</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B17/0853</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B17/085</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B17/085</class-ref> and <class-ref scheme="cpc">E21B17/0853</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/10" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/10</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Wear protectors</text></title-part><title-part><text>Centralising devices </text><CPC-specific-text><text>, e.g. stabilisers</text></CPC-specific-text><text> </text><reference><text>drives used in the borehole with anchoring means <class-ref scheme="cpc">E21B4/18</class-ref>; guiding or centralising devices outside the borehole <class-ref scheme="cpc">E21B19/24</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/1007" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1007</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>for the internal surface of a pipe, e.g. wear bushings for underwater well-heads</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/1014" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1014</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Flexible or expansible centering means, e.g. with pistons pressing against the wall of the well </text><reference><text><class-ref scheme="cpc">E21B17/1042</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/1021" definition-exists="true" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/1021</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>with articulated arms or arcuate springs</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B17/1028" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1028</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with arcuate springs only, e.g. baskets with outwardly bowed strips for cementing operations</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/1035" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1035</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>for plural rods, pipes or lines, e.g. for control lines</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/1042" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1042</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Elastomer protector or centering means</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/105" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/105</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>split type</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/1057" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1057</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Centralising devices with rollers or with a relatively rotating sleeve </text><reference><text><class-ref scheme="cpc">E21B17/1014</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B17/1064" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1064</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Pipes or rods with a relatively rotating sleeve</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/1071" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1071</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>specially adapted for pump rods, e.g. sucker rods</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/1078" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2016-05-01" status="published"><classification-symbol>E21B17/1078</classification-symbol><class-title date-revised="2016-05-01"><title-part><CPC-specific-text><text>Stabilisers or centralisers for casing, tubing or drill pipes </text><reference><text>devices for off-center positioning <class-ref scheme="cpc">E21B17/10</class-ref>; <class-ref scheme="cpc">E21B17/1007</class-ref>&#160;-&#160;<class-ref scheme="cpc">E21B17/1064</class-ref> take precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/1085" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1085</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Wear protectors; Blast joints; Hard facing </text><reference><text>wear protection included in centralising devices, see relevant subgroups</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/1092" definition-exists="false" ipc-concordant="E21B17/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/1092</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Gauge section of drill bits</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/12" definition-exists="false" ipc-concordant="E21B17/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/12</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Devices for placing or drawing out wear protectors</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/14" definition-exists="false" ipc-concordant="E21B17/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/14</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Casing shoes </text><CPC-specific-text><text>for the protection of the bottom of the casing</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/16" definition-exists="false" ipc-concordant="E21B17/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/16</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Drill collars</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/18" definition-exists="true" ipc-concordant="E21B17/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/18</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Pipes provided with plural fluid passages </text><reference><CPC-specific-text><text><class-ref scheme="cpc">E21B17/203</class-ref> takes precedence;</text></CPC-specific-text><text> circulation of drilling fluid by means of such pipes <class-ref scheme="cpc">E21B21/12</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/20" definition-exists="true" ipc-concordant="E21B17/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/20</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Flexible or articulated drilling pipes </text><CPC-specific-text><text>, e.g. flexible or articulated rods, pipes or cables</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/203" definition-exists="false" ipc-concordant="E21B17/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/203</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with plural fluid passages</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B17/206" definition-exists="true" ipc-concordant="E21B17/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B17/206</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>with conductors, e.g. electrical, optical</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B17/22" definition-exists="true" ipc-concordant="E21B17/22" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B17/22</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Rods or pipes with helical structure </text><reference><text>drill bits with helical conveying portion <class-ref scheme="cpc">E21B10/44</class-ref></text></reference></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B19/00" definition-exists="true" ipc-concordant="E21B19/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick</text></title-part><title-part><text>Apparatus for feeding the rods or cables </text><reference><text>surface drives <class-ref scheme="cpc">E21B1/02</class-ref>, <class-ref scheme="cpc">E21B3/02</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/002" definition-exists="true" ipc-concordant="E21B19/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/002</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>specially adapted for underwater drilling </text><reference><text><class-ref scheme="cpc">E21B19/09</class-ref>, <class-ref scheme="cpc">E21B19/143</class-ref> take precedence</text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/004" definition-exists="false" ipc-concordant="E21B19/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/004</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>supporting a riser from a drilling or production platform</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B19/006" definition-exists="false" ipc-concordant="E21B19/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/006</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>including heave compensators</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/008" definition-exists="true" ipc-concordant="E21B19/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/008</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Winding units, specially adapted for drilling operations</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/02" definition-exists="true" ipc-concordant="E21B19/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-08-01" status="published"><classification-symbol>E21B19/02</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>Rod or cable suspensions </text><reference><text>load-engaging elements for hoisting or lowering purposes in general <class-ref scheme="cpc">B66C1/00</class-ref>; crown blocks or pulley blocks <class-ref scheme="cpc">B66D</class-ref>; cable guides <class-ref scheme="cpc">B66D1/36</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/04" definition-exists="false" ipc-concordant="E21B19/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Hooks</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/06" definition-exists="false" ipc-concordant="E21B19/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/06</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Elevators, i.e. rod- or tube-gripping devices</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B19/07" definition-exists="false" ipc-concordant="E21B19/07" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/07</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Slip-type elevators </text><reference><text>slips in rotary tables <class-ref scheme="cpc">E21B19/10</class-ref></text></reference></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/08" definition-exists="true" ipc-concordant="E21B19/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Apparatus for feeding the rods or cables </text><reference><text><class-ref scheme="cpc">E21B19/22</class-ref> takes precedence; automatic feed <class-ref scheme="cpc">E21B44/02</class-ref>; hoisting drums <class-ref scheme="cpc">B66D</class-ref></text></reference></title-part><title-part><text>Apparatus for increasing or decreasing the pressure on the drilling tool</text></title-part><title-part><text>Apparatus for counterbalancing the weight of the rods</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B19/08</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B19/081</class-ref>, <class-ref scheme="cpc">E21B19/083</class-ref>, <class-ref scheme="cpc">E21B19/084</class-ref>, <class-ref scheme="cpc">E21B19/086</class-ref>, <class-ref scheme="cpc">E21B19/087</class-ref>, <class-ref scheme="cpc">E21B19/089</class-ref>, and <class-ref scheme="cpc">E21B19/09</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/081" definition-exists="false" ipc-concordant="E21B19/081" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/081</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Screw-and-nut feed mechanisms</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B19/081</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B19/08</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B19/08</class-ref> and <class-ref scheme="cpc">E21B19/081</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/083" definition-exists="false" ipc-concordant="E21B19/083" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/083</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Cam, rack or like feed mechanisms</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B19/083</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B19/08</class-ref>. <br/>Groups <class-ref scheme="cpc">E21B19/08</class-ref> and <class-ref scheme="cpc">E21B19/083</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/084" definition-exists="false" ipc-concordant="E21B19/084" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/084</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with flexible drawing means, e.g. cables</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B19/084</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B19/08</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B19/08</class-ref> and <class-ref scheme="cpc">E21B19/084</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/086" definition-exists="false" ipc-concordant="E21B19/086" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/086</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with a fluid-actuated cylinder </text><reference><text><class-ref scheme="cpc">E21B19/084</class-ref>, <class-ref scheme="cpc">E21B19/087</class-ref>, <class-ref scheme="cpc">E21B19/09</class-ref> take precedence</text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B19/086</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B19/08</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B19/08</class-ref> and <class-ref scheme="cpc">E21B19/086</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/087" definition-exists="false" ipc-concordant="E21B19/087" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/087</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>by means of a swinging arm</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B19/087</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B19/08</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B19/08</class-ref> and <class-ref scheme="cpc">E21B19/087</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/089" definition-exists="false" ipc-concordant="E21B19/089" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/089</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with a spring or an additional weight</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B19/089</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B19/08</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B19/08</class-ref> and <class-ref scheme="cpc">E21B19/089</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/09" definition-exists="true" ipc-concordant="E21B19/09" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/09</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>specially adapted for drilling underwater formations from a floating support using heave compensators supporting the drill string </text><reference><text>drilling-pipe telescoping joints <class-ref scheme="cpc">E21B17/07</class-ref> </text><CPC-specific-text><text>; heave compensators for supporting a riser <class-ref scheme="cpc">E21B19/006</class-ref></text></CPC-specific-text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B19/09</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B19/08</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B19/08</class-ref> and <class-ref scheme="cpc">E21B19/09</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/10" definition-exists="true" ipc-concordant="E21B19/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/10</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Slips</text></title-part><title-part><text>Spiders </text><CPC-specific-text><text>; Catching devices </text><reference><text>rotary tables with master bushing or kelly bushing <class-ref scheme="cpc">E21B3/04</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B19/10</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B19/102</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B19/10</class-ref> and <class-ref scheme="cpc">E21B19/102</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/102" definition-exists="false" ipc-concordant="E21B19/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/102</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using rollers or spherical balls as load gripping elements</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B19/102</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B19/10</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B19/10</class-ref> and <class-ref scheme="cpc">E21B19/102</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/12" definition-exists="true" ipc-concordant="E21B19/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/12</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Rope clamps </text><CPC-specific-text><text>; Rod, casings or tube clamps not secured to elevators</text></CPC-specific-text><text> </text><reference><text>rope clamps in general <class-ref scheme="cpc">F16G11/00</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/14" definition-exists="true" ipc-concordant="E21B19/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B19/14</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Racks, ramps, troughs or bins, for holding the lengths of rod singly or connected</text></title-part><title-part><text>Handling between storage place and borehole </text><reference><text><class-ref scheme="cpc">E21B19/20</class-ref>, <class-ref scheme="cpc">E21B19/22</class-ref> take precedence</text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/143" definition-exists="false" ipc-concordant="E21B19/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/143</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>specially adapted for underwater drilling</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/146" definition-exists="false" ipc-concordant="E21B19/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/146</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Carousel systems, i.e. rotating rack systems</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/15" definition-exists="false" ipc-concordant="E21B19/15" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/15</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Racking of rods in horizontal position</text></title-part><title-part><text>Handling between horizontal and vertical position</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B19/155" definition-exists="false" ipc-concordant="E21B19/15" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/155</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Handling between horizontal and vertical position</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/16" definition-exists="true" ipc-concordant="E21B19/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-08-01" status="published"><classification-symbol>E21B19/16</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>Connecting or disconnecting pipe couplings or joints </text><reference><text><class-ref scheme="cpc">E21B19/20</class-ref> takes precedence; pipe wrenches or the like <class-ref scheme="cpc">B25B</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/161" definition-exists="false" ipc-concordant="E21B19/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/161</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using a wrench or a spinner adapted to engage a circular section of pipe </text><reference><text><class-ref scheme="cpc">E21B19/168</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B19/162" definition-exists="false" ipc-concordant="E21B19/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/162</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>cathead actuated</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B19/163" definition-exists="false" ipc-concordant="E21B19/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/163</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>piston-cylinder actuated</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B19/164" definition-exists="false" ipc-concordant="E21B19/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/164</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>motor actuated </text><reference><text><class-ref scheme="cpc">E21B19/162</class-ref> and <class-ref scheme="cpc">E21B19/163</class-ref> take precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/165" definition-exists="false" ipc-concordant="E21B19/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/165</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Control or monitoring arrangements therefor</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B19/166" definition-exists="false" ipc-concordant="E21B19/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/166</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Arrangements of torque limiters or torque indicators</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/167" definition-exists="false" ipc-concordant="E21B19/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/167</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using a wrench adapted to engage a non circular section of pipe, e.g. a section with flats or splines</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B19/168" definition-exists="false" ipc-concordant="E21B19/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/168</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using a spinner with rollers or a belt adapted to engage a well pipe</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/18" definition-exists="false" ipc-concordant="E21B19/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/18</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Connecting or disconnecting drill bit and drilling pipe</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/20" definition-exists="true" ipc-concordant="E21B19/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/20</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Combined feeding from rack and connecting, e.g. automatically</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/22" definition-exists="false" ipc-concordant="E21B19/22" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/22</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Handling reeled pipe or rod units, e.g. flexible drilling pipes </text><CPC-specific-text><reference><text>lifting or hauling appliances using two or more cooperating endless chains <class-ref scheme="cpc">B66D3/003</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B19/24" definition-exists="false" ipc-concordant="E21B19/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B19/24</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Guiding or centralising devices for drilling rods or pipes</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B21/00" definition-exists="true" ipc-concordant="E21B21/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor </text><reference><text>freeing objects stuck in boreholes by flushing <class-ref scheme="cpc">E21B31/03</class-ref>; well drilling compositions <class-ref scheme="cpc">C09K8/02</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B21/00</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B21/001</class-ref>, <class-ref scheme="cpc">E21B21/002</class-ref>, <class-ref scheme="cpc">E21B21/003</class-ref>, <class-ref scheme="cpc">E21B21/01</class-ref>, <class-ref scheme="cpc">E21B21/012</class-ref>, <class-ref scheme="cpc">E21B21/015</class-ref>, <class-ref scheme="cpc">E21B21/019</class-ref>, <class-ref scheme="cpc">E21B21/02</class-ref>, <class-ref scheme="cpc">E21B21/06</class-ref>, <class-ref scheme="cpc">E21B21/062</class-ref>, <class-ref scheme="cpc">E21B21/063</class-ref>, <class-ref scheme="cpc">E21B21/065</class-ref>, <class-ref scheme="cpc">E21B21/066</class-ref>, <class-ref scheme="cpc">E21B21/067</class-ref>, <class-ref scheme="cpc">E21B21/068</class-ref>, <class-ref scheme="cpc">E21B21/07</class-ref>, <class-ref scheme="cpc">E21B21/08</class-ref>, <class-ref scheme="cpc">E21B21/082</class-ref>, <class-ref scheme="cpc">E21B21/085</class-ref>, <class-ref scheme="cpc">E21B21/10</class-ref>, <class-ref scheme="cpc">E21B21/103</class-ref>, <class-ref scheme="cpc">E21B21/106</class-ref>, <class-ref scheme="cpc">E21B21/12</class-ref>, <class-ref scheme="cpc">E21B21/14</class-ref>, <class-ref scheme="cpc">E21B21/16</class-ref>, and <class-ref scheme="cpc">E21B21/18</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/001" definition-exists="false" ipc-concordant="E21B21/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/001</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>specially adapted for underwater drilling </text><reference><text>dual gradient drilling <class-ref scheme="cpc">E21B21/082</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/001</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Group <class-ref scheme="cpc">E21B21/001</class-ref> is also impacted by reclassification into group <class-ref scheme="cpc">E21B21/082</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref>, <class-ref scheme="cpc">E21B21/001</class-ref>, and <class-ref scheme="cpc">E21B21/082</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/002" definition-exists="false" ipc-concordant="E21B21/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/002</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Down-hole drilling fluid separation systems </text><reference><text>containers comprising collecting means with a strainer <class-ref scheme="cpc">E21B27/005</class-ref>; subsoil filtering <class-ref scheme="cpc">E21B43/02</class-ref>; down-hole production separators <class-ref scheme="cpc">E21B43/38</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/002</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref> and <class-ref scheme="cpc">E21B21/002</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/003" definition-exists="false" ipc-concordant="E21B21/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/003</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Means for stopping loss of drilling fluid </text><reference><text>plastering the borehole wall <class-ref scheme="cpc">E21B33/138</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/003</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref> and <class-ref scheme="cpc">E21B21/003</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/01" definition-exists="true" ipc-concordant="E21B21/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/01</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Arrangements for handling drilling fluids or cuttings outside the borehole, e.g. mud boxes </text><reference><text>arrangements for treating drilling fluids <class-ref scheme="cpc">E21B21/06</class-ref> </text><CPC-specific-text><text>; waste disposal systems <class-ref scheme="cpc">E21B41/005</class-ref></text></CPC-specific-text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/01</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Group <class-ref scheme="cpc">E21B21/01</class-ref> is also impacted by reclassification into group <class-ref scheme="cpc">E21B21/019</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref>, <class-ref scheme="cpc">E21B21/01</class-ref>, and <class-ref scheme="cpc">E21B21/019</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/011" definition-exists="false" ipc-concordant="E21B21/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/011</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Dust eliminating or dust removing while drilling</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B21/012" definition-exists="false" ipc-concordant="E21B21/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/012</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using exhaust air from the drilling motor for blowing off the dust at the borehole entrance</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/012</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref> and <class-ref scheme="cpc">E21B21/012</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B21/013" definition-exists="false" ipc-concordant="E21B21/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/013</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>by liquids</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B21/0135" definition-exists="false" ipc-concordant="E21B21/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/0135</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Liquid flushing installations</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B21/014" definition-exists="false" ipc-concordant="E21B21/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/014</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Preventing exhaust air from the drill motor from blowing-off towards the working face</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/015" definition-exists="false" ipc-concordant="E21B21/015" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/015</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Means engaging the bore entrance, e.g. hoods for collecting dust</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/015</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Group <class-ref scheme="cpc">E21B21/015</class-ref> is also impacted by reclassification into group <class-ref scheme="cpc">E21B21/019</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref>, <class-ref scheme="cpc">E21B21/015</class-ref>, and <class-ref scheme="cpc">E21B21/019</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/019" definition-exists="false" ipc-concordant="E21B21/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/019</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Arrangements for maintaining circulation of drilling fluid while connecting or disconnecting tubular joints</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/019</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B21/00</class-ref>, <class-ref scheme="cpc">E21B21/01</class-ref>, and <class-ref scheme="cpc">E21B21/015</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/02" definition-exists="true" ipc-concordant="E21B21/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/02</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Swivel joints in hose-lines</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/02</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref> and <class-ref scheme="cpc">E21B21/02</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/06" definition-exists="false" ipc-concordant="E21B21/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Arrangements for treating drilling fluids outside the borehole </text><reference><text>treating steps <u>per se</u>, <u>see</u> the relevant subclasses</text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Groups <class-ref scheme="cpc">E21B21/06</class-ref> - <class-ref scheme="cpc">E21B21/07</class-ref> are incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/062" definition-exists="false" ipc-concordant="E21B21/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B21/062</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>by mixing components</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/063" definition-exists="false" ipc-concordant="E21B21/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B21/063</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>by separating components</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B21/065" definition-exists="false" ipc-concordant="E21B21/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B21/065</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Separating solids from drilling fluids</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B21/066" definition-exists="false" ipc-concordant="E21B21/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B21/066</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with further treatment of the solids, e.g. for disposal</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B21/067" definition-exists="false" ipc-concordant="E21B21/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B21/067</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Separating gases from drilling fluids</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/068" definition-exists="false" ipc-concordant="E21B21/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B21/068</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using chemical treatment</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/07" definition-exists="false" ipc-concordant="E21B21/07" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B21/07</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>for treating dust-laden gaseous fluids</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/08" definition-exists="false" ipc-concordant="E21B21/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure </text><reference><text>valve arrangements therefor <class-ref scheme="cpc">E21B21/10</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/08</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Group <class-ref scheme="cpc">E21B21/08</class-ref> is also impacted by reclassification into groups <class-ref scheme="cpc">E21B21/082</class-ref> and <class-ref scheme="cpc">E21B21/085</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/082" definition-exists="false" ipc-concordant="E21B21/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/082</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Dual gradient systems, i.e. using two hydrostatic gradients or drilling fluid densities</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/082</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B21/00</class-ref>, <class-ref scheme="cpc">E21B21/001</class-ref>, and <class-ref scheme="cpc">E21B21/08</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/085" definition-exists="false" ipc-concordant="E21B21/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/085</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Underbalanced techniques, i.e. where borehole fluid pressure is below formation pressure</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/085</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B21/00</class-ref> and <class-ref scheme="cpc">E21B21/08</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref>, <class-ref scheme="cpc">E21B21/08</class-ref>, and <class-ref scheme="cpc">E21B21/085</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/10" definition-exists="true" ipc-concordant="E21B21/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/10</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Valve arrangements in drilling-fluid circulation systems </text><reference><text>valves in general <class-ref scheme="cpc">F16K</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Groups <class-ref scheme="cpc">E21B21/10</class-ref> - <class-ref scheme="cpc">E21B21/106</class-ref> are incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/103" definition-exists="false" ipc-concordant="E21B21/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B21/103</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Down-hole by-pass valve arrangements, i.e. between the inside of the drill string and the annulus</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B21/106" definition-exists="false" ipc-concordant="E21B21/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B21/106</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Valve arrangements outside the borehole, e.g. kelly valves</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/12" definition-exists="true" ipc-concordant="E21B21/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/12</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using drilling pipes with plural fluid passages, e.g. closed circulation systems </text><reference><text>pipes with plural fluid passages <class-ref scheme="cpc">E21B17/18</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/12</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref> and <class-ref scheme="cpc">E21B21/12</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/14" definition-exists="false" ipc-concordant="E21B21/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/14</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using liquids and gases, e.g. foams</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/14</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref> and <class-ref scheme="cpc">E21B21/14</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/16" definition-exists="false" ipc-concordant="E21B21/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/16</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using gaseous fluids </text><reference><text><class-ref scheme="cpc">E21B21/14</class-ref> takes precedence; arrangements for handling drilling fluids outside the borehole <class-ref scheme="cpc">E21B21/01</class-ref>; arrangements for treating drilling fluids <class-ref scheme="cpc">E21B21/06</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/16</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref> and <class-ref scheme="cpc">E21B21/16</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B21/18" definition-exists="false" ipc-concordant="E21B21/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B21/18</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Preventing exhaust air from the drill motor from blowing-off towards the working face</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B21/18</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B21/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B21/00</class-ref> and <class-ref scheme="cpc">E21B21/18</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B23/00" definition-exists="true" ipc-concordant="E21B23/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B23/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Apparatus for displacing, setting, locking, releasing, or removing tools, packers or the like in the boreholes or wells </text><reference><text>setting of casings, screens or liners <class-ref scheme="cpc">E21B43/10</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B23/001" definition-exists="false" ipc-concordant="E21B23/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/001</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Self-propelling systems or apparatus, e.g. for moving tools within the horizontal portion of a borehole</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B23/004" definition-exists="false" ipc-concordant="E21B23/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B23/004</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Indexing systems for guiding relative movement between telescoping parts of downhole tools</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/006" definition-exists="false" ipc-concordant="E21B23/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B23/006</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>&quot;J-slot&quot; systems, i.e. lug and slot indexing mechanisms</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B23/01" definition-exists="true" ipc-concordant="E21B23/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/01</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>for anchoring the tools or the like </text><reference><text><class-ref scheme="cpc">E21B23/02</class-ref>&#160;-&#160;<class-ref scheme="cpc">E21B23/06</class-ref> take precedence; anchoring of drives in the borehole <class-ref scheme="cpc">E21B4/18</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B23/02" definition-exists="false" ipc-concordant="E21B23/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2016-05-01" status="published"><classification-symbol>E21B23/02</classification-symbol><class-title date-revised="2016-05-01"><title-part><text>for locking the tools or the like in landing nipples or in recesses between adjacent sections of tubing </text><reference><text><class-ref scheme="cpc">E21B23/03</class-ref>&#160;-&#160;<class-ref scheme="cpc">E21B23/06</class-ref> take precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B23/03" definition-exists="false" ipc-concordant="E21B23/03" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/03</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>for setting the tools into, or removing the tools from, laterally offset landing nipples or pockets</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B23/03</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B23/12</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/03</class-ref> and <class-ref scheme="cpc">E21B23/12</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B23/04" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>operated by fluid means, e.g. actuated by explosion </text><reference><text><class-ref scheme="cpc">E21B23/06</class-ref>, <class-ref scheme="cpc">E21B23/08</class-ref> take precedence</text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B23/04</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B23/0411</class-ref>, <class-ref scheme="cpc">E21B23/04115</class-ref>, <class-ref scheme="cpc">E21B23/0412</class-ref>, <class-ref scheme="cpc">E21B23/0413</class-ref>, <class-ref scheme="cpc">E21B23/0414</class-ref>, <class-ref scheme="cpc">E21B23/0415</class-ref>, <class-ref scheme="cpc">E21B23/0416</class-ref>, <class-ref scheme="cpc">E21B23/0417</class-ref>, <class-ref scheme="cpc">E21B23/0418</class-ref>, <class-ref scheme="cpc">E21B23/0419</class-ref>, <class-ref scheme="cpc">E21B23/042</class-ref>, <class-ref scheme="cpc">E21B23/0421</class-ref>, <class-ref scheme="cpc">E21B23/0422</class-ref>, <class-ref scheme="cpc">E21B23/0423</class-ref>, and <class-ref scheme="cpc">E21B34/142</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0411" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0411</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>specially adapted for anchoring tools or the like to the borehole wall or to well tube</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0411</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0411</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B23/04115" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/04115</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using radial pistons</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/04115</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/04115</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0412" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0412</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>characterised by pressure chambers, e.g. vacuum chambers</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0412</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0412</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0413" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0413</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using means for blocking fluid flow, e.g. drop balls or darts </text><reference><text>using balls or the like for actuating downhole valves <class-ref scheme="cpc">E21B34/142</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0413</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0413</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0414" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0414</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using explosives</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0414</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0414</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0415" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0415</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using particular fluids, e.g. electro-active liquids</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0415</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0415</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0416" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0416</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>characterised by force amplification arrangements</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0416</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0416</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0417" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0417</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Down-hole non-explosive gas generating means, e.g. by chemical reaction</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0417</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0417</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0418" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0418</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>specially adapted for locking the tools in landing nipples or recesses</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0418</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0418</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0419" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0419</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using down-hole motor and pump arrangements for generating hydraulic pressure</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0419</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0419</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/042" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/042</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using a single piston or multiple mechanically interconnected pistons</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/042</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/042</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0421" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0421</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using multiple hydraulically interconnected pistons</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0421</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0421</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0422" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0422</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>characterised by radial pistons </text><reference><text>using radial pistons for anchoring <class-ref scheme="cpc">E21B23/04115</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0422</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0422</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/0423" definition-exists="false" ipc-concordant="E21B23/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/0423</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using step motors</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/0423</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/04</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B23/0423</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B23/06" definition-exists="false" ipc-concordant="E21B23/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B23/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>for setting packers</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/065" definition-exists="false" ipc-concordant="E21B23/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B23/065</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>setting tool actuated by explosion or gas generating means</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B23/08" definition-exists="true" ipc-concordant="E21B23/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/08</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Introducing or running tools by fluid pressure, e.g. through-the-flow-line tool systems </text><reference><text>special provisions on heads therefor <class-ref scheme="cpc">E21B33/068</class-ref>; cementing plugs <class-ref scheme="cpc">E21B33/16</class-ref>; scrapers operated by fluid pressure <class-ref scheme="cpc">E21B37/04</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/10" definition-exists="false" ipc-concordant="E21B23/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B23/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Tools specially adapted therefor</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B23/12" definition-exists="true" ipc-concordant="E21B23/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/12</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Tool diverters</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B23/12</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B23/03</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/03</class-ref> and <class-ref scheme="cpc">E21B23/12</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B23/14" definition-exists="true" ipc-concordant="E21B23/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B23/14</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>for displacing a cable or cable-operated tool, e.g. for logging or perforating operations in deviated wells </text><reference><text>by fluid pressure <class-ref scheme="cpc">E21B23/08</class-ref>; provision on well heads for introducing or removing cable-operated tools <class-ref scheme="cpc">E21B33/072</class-ref>, <class-ref scheme="cpc">E21B33/076</class-ref></text></reference></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B25/00" definition-exists="true" ipc-concordant="E21B25/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Apparatus for obtaining or removing undisturbed cores, e.g. core barrels, core extractors </text><reference><text>core bits <class-ref scheme="cpc">E21B10/02</class-ref>; using explosives or projectiles in boreholes <class-ref scheme="cpc">E21B49/04</class-ref>; side-wall sampling or coring <class-ref scheme="cpc">E21B49/06</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B25/005" definition-exists="false" ipc-concordant="E21B25/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/005</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Above ground means for handling the core, e.g. for extracting the core from the core barrel</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B25/02" definition-exists="true" ipc-concordant="E21B25/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe </text><reference><text>retrievable drill bits <class-ref scheme="cpc">E21B10/64</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B25/04" definition-exists="false" ipc-concordant="E21B25/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-01-01" status="published"><classification-symbol>E21B25/04</classification-symbol><class-title date-revised="2017-01-01"><title-part><text>the core receiver having a core forming cutting edge or element, e.g. punch type core barrels</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B25/06" definition-exists="false" ipc-concordant="E21B25/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>the core receiver having a flexible liner or inflatable retaining means</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B25/08" definition-exists="false" ipc-concordant="E21B25/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Coating, freezing, consolidating cores </text><reference><text><class-ref scheme="cpc">E21B25/06</class-ref> takes precedence</text></reference></title-part><title-part><text>Recovering uncontaminated cores or cores at formation pressure</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B25/10" definition-exists="false" ipc-concordant="E21B25/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Formed core retaining or severing means </text><reference><text><class-ref scheme="cpc">E21B25/06</class-ref>, <class-ref scheme="cpc">E21B25/08</class-ref> take precedence</text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B25/12" definition-exists="false" ipc-concordant="E21B25/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/12</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>of the sliding wedge type</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B25/14" definition-exists="false" ipc-concordant="E21B25/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/14</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>mounted on pivot transverse to core axis</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B25/16" definition-exists="false" ipc-concordant="E21B25/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/16</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>for obtaining oriented cores</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B25/18" definition-exists="false" ipc-concordant="E21B25/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B25/18</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>the core receiver being specially adapted for operation under water</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B27/00" definition-exists="true" ipc-concordant="E21B27/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B27/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Containers for collecting or depositing substances in boreholes or wells, e.g. bailers, </text><CPC-specific-text><text>baskets or buckets</text></CPC-specific-text><text> for collecting mud or sand</text></title-part><title-part><text>Drill bits with means for collecting substances, e.g. valve drill bits</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B27/00</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B11/04</class-ref> and <class-ref scheme="cpc">E21B31/08</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B27/00</class-ref>, <class-ref scheme="cpc">E21B11/04</class-ref>, and <class-ref scheme="cpc">E21B31/08</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B27/005" definition-exists="false" ipc-concordant="E21B27/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B27/005</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Collecting means with a strainer</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B27/02" definition-exists="false" ipc-concordant="E21B27/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B27/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Dump bailers, i.e. containers for depositing substances, e.g. cement or acids</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B27/04" definition-exists="false" ipc-concordant="E21B27/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B27/04</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>where the collecting or depositing means include helical conveying means </text><CPC-specific-text><reference><text>drilling with helical conveying means combined with bucket-type container <class-ref scheme="cpc">E21B7/006</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B28/00" definition-exists="true" ipc-concordant="E21B28/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-08-01" status="published"><classification-symbol>E21B28/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Vibration generating arrangements for boreholes or wells, e.g. for stimulating production </text><reference><text>for drilling <class-ref scheme="cpc">E21B7/24</class-ref>; </text><CPC-specific-text><text>for fishing for or freeing objects <class-ref scheme="cpc">E21B31/005</class-ref>;</text></CPC-specific-text><text> for transmitting measuring-signals <class-ref scheme="cpc">E21B47/14</class-ref>; for geophysical measurements <class-ref scheme="cpc">G01V1/02</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B29/00" definition-exists="true" ipc-concordant="E21B29/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B29/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Cutting or destroying pipes, packers, plugs, or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows </text><reference><text>perforators <class-ref scheme="cpc">E21B43/11</class-ref></text></reference></title-part><title-part><text>Deforming of pipes in boreholes or wells</text></title-part><title-part><text>Reconditioning of well casings while in the ground </text><CPC-specific-text><reference><text>by enlarging drilled holes or counterboring <class-ref scheme="cpc">E21B7/28</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B29/002" definition-exists="false" ipc-concordant="E21B29/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B29/002</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Cutting, e.g. milling, a pipe with a cutter rotating along the circumference of the pipe</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B29/005" definition-exists="false" ipc-concordant="E21B29/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B29/005</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with a radially-expansible cutter rotating inside the pipe, e.g. for cutting an annular window</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B29/007" definition-exists="false" ipc-concordant="E21B29/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B29/007</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with a radially-retracting cutter rotating outside the pipe</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B29/02" definition-exists="false" ipc-concordant="E21B29/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B29/02</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by explosives or by thermal or chemical means </text><reference><CPC-specific-text><text>freeing stuck objects by explosives <class-ref scheme="cpc">E21B31/002</class-ref>;</text></CPC-specific-text><text> destroying objects in boreholes or wells by explosives <class-ref scheme="cpc">E21B31/16</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B29/04" definition-exists="false" ipc-concordant="E21B29/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B29/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Cutting of wire lines or the like </text><reference><text><class-ref scheme="cpc">E21B29/02</class-ref> takes precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B29/06" definition-exists="true" ipc-concordant="E21B29/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B29/06</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Cutting windows, e.g. directional window cutters for whipstock operations </text><reference><CPC-specific-text><text><class-ref scheme="cpc">E21B29/005</class-ref> and</text></CPC-specific-text><text> <class-ref scheme="cpc">E21B29/08</class-ref> take precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B29/08" definition-exists="false" ipc-concordant="E21B29/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B29/08</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Cutting or deforming pipes to control fluid flow </text><CPC-specific-text><reference><text>shear type blow-out preventers <class-ref scheme="cpc">E21B33/063</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B29/10" definition-exists="false" ipc-concordant="E21B29/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B29/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Reconditioning of well casings, e.g. straightening</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B29/12" definition-exists="false" ipc-concordant="E21B29/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B29/12</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>specially adapted for underwater installations </text><reference><text><class-ref scheme="cpc">E21B29/08</class-ref> takes precedence</text></reference></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B31/00" definition-exists="true" ipc-concordant="E21B31/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B31/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Fishing for or freeing objects in boreholes or wells </text><reference><text>provisions on well heads for introducing or removing objects <class-ref scheme="cpc">E21B33/068</class-ref>; locating or determining the position of objects in boreholes or wells <class-ref scheme="cpc">E21B47/09</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B31/00</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B31/08</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B31/00</class-ref> and <class-ref scheme="cpc">E21B31/08</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B31/002" definition-exists="true" ipc-concordant="E21B31/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B31/002</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Destroying the objects to be fished, e.g. by explosive means</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B31/005" definition-exists="true" ipc-concordant="E21B31/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B31/005</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using vibrating or oscillating means</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B31/007" definition-exists="false" ipc-concordant="E21B31/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/007</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>fishing tools with means for attaching comprising fusing or sticking</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B31/03" definition-exists="false" ipc-concordant="E21B31/03" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B31/03</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Freeing by flushing</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B31/03</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B31/035</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B31/03</class-ref> and <class-ref scheme="cpc">E21B31/035</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B31/035" definition-exists="false" ipc-concordant="E21B31/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B31/035</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>controlling differential pipe sticking</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B31/035</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B31/03</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B31/03</class-ref> and <class-ref scheme="cpc">E21B31/035</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B31/06" definition-exists="false" ipc-concordant="E21B31/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using magnetic means</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B31/08" definition-exists="false" ipc-concordant="E21B31/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B31/08</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using junk baskets or the like</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B31/08</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B27/00</class-ref> and <class-ref scheme="cpc">E21B31/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B27/00</class-ref>, <class-ref scheme="cpc">E21B31/00</class-ref>, and <class-ref scheme="cpc">E21B31/08</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B31/107" definition-exists="true" ipc-concordant="E21B31/107" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/107</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using impact means for releasing stuck parts, e.g. jars </text><reference><text>telescoping joints <class-ref scheme="cpc">E21B17/07</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B31/1075" definition-exists="false" ipc-concordant="E21B31/107" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/1075</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using explosives</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B31/113" definition-exists="false" ipc-concordant="E21B31/113" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/113</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>hydraulically-operated</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B31/1135" definition-exists="false" ipc-concordant="E21B31/113" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-05-01" status="published"><classification-symbol>E21B31/1135</classification-symbol><class-title date-revised="2017-05-01"><title-part><CPC-specific-text><text>Jars with a hydraulic impedance mechanism, i.e. a restriction, for initially delaying escape of a restraining fluid</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B31/12" definition-exists="false" ipc-concordant="E21B31/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/12</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Grappling tools, e.g. tongs or grabs</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B31/125" definition-exists="false" ipc-concordant="E21B31/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/125</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>specially adapted for parted wire line or ropes</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B31/14" definition-exists="false" ipc-concordant="E21B31/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B31/14</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>with means deflecting the direction of the tool, e.g. by use of knuckle joints </text><reference><text>apparatus for deflecting the boring </text><CPC-specific-text><text><class-ref scheme="cpc">E21B7/06</class-ref></text></CPC-specific-text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B31/16" definition-exists="false" ipc-concordant="E21B31/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/16</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>combined with cutting or destroying means </text><reference><text>cutting or destroying means <u>per se</u> <class-ref scheme="cpc">E21B29/00</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B31/18" definition-exists="false" ipc-concordant="E21B31/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/18</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>gripping externally, e.g. overshot</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B31/20" definition-exists="false" ipc-concordant="E21B31/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B31/20</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>gripping internally, e.g. fishing spears</text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B33/00" definition-exists="true" ipc-concordant="E21B33/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Sealing or packing boreholes or wells</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B33/00</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B2200/00</class-ref>, <class-ref scheme="cpc">E21B2200/01</class-ref>, <class-ref scheme="cpc">E21B2200/02</class-ref>, <class-ref scheme="cpc">E21B2200/03</class-ref>, <class-ref scheme="cpc">E21B2200/04</class-ref>, <class-ref scheme="cpc">E21B2200/05</class-ref>, <class-ref scheme="cpc">E21B2200/06</class-ref>, <class-ref scheme="cpc">E21B2200/08</class-ref>, <class-ref scheme="cpc">E21B2200/09</class-ref>, <class-ref scheme="cpc">E21B2200/20</class-ref>, and <class-ref scheme="cpc">E21B2200/22</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B33/02" definition-exists="true" ipc-concordant="E21B33/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Surface sealing or packing</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B33/03" definition-exists="false" ipc-concordant="E21B33/03" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/03</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Well heads</text></title-part><title-part><text>Setting-up thereof </text><reference><text>valve arrangements therefor <class-ref scheme="cpc">E21B34/02</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/035" definition-exists="false" ipc-concordant="E21B33/035" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/035</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>specially adapted for underwater installations </text><reference><text><class-ref scheme="cpc">E21B33/043</class-ref>, <class-ref scheme="cpc">E21B33/064</class-ref>, <class-ref scheme="cpc">E21B33/076</class-ref> take precedence</text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B33/035</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B33/0353</class-ref> and <class-ref scheme="cpc">E21B33/0387</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/035</class-ref>, <class-ref scheme="cpc">E21B33/0353</class-ref>, and <class-ref scheme="cpc">E21B33/0387</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/0353" definition-exists="false" ipc-concordant="E21B33/035" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/0353</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Horizontal or spool trees, i.e. without production valves in the vertical main bore</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B33/0353</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B33/035</class-ref>, <class-ref scheme="cpc">E21B33/0355</class-ref>, <class-ref scheme="cpc">E21B33/037</class-ref>, <class-ref scheme="cpc">E21B33/0375</class-ref>, <class-ref scheme="cpc">E21B33/038</class-ref>, <class-ref scheme="cpc">E21B33/0385</class-ref>, and <class-ref scheme="cpc">E21B33/0422</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/0355" definition-exists="false" ipc-concordant="E21B33/035" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/0355</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Control systems, e.g. hydraulic, pneumatic, electric, acoustic, for submerged well heads</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B33/0355</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B33/0353</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/0355</class-ref> and <class-ref scheme="cpc">E21B33/0353</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/037" definition-exists="false" ipc-concordant="E21B33/037" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/037</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>Protective housings therefor</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B33/037</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B33/0353</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/037</class-ref> and <class-ref scheme="cpc">E21B33/0353</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B33/0375" definition-exists="true" ipc-concordant="E21B33/037" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/0375</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Corrosion protection means</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B33/0375</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B33/0353</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/0375</class-ref> and <class-ref scheme="cpc">E21B33/0353</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/038" definition-exists="false" ipc-concordant="E21B33/038" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/038</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Connectors used on well heads, e.g. for connecting blow-out preventer and riser </text><reference><text>connecting a production flow-line to an underwater well head <class-ref scheme="cpc">E21B43/013</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B33/038</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B33/0353</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/038</class-ref> and <class-ref scheme="cpc">E21B33/0353</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B33/0385" definition-exists="true" ipc-concordant="E21B33/038" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/0385</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>electrical connectors</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B33/0385</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B33/0353</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/0385</class-ref> and <class-ref scheme="cpc">E21B33/0353</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/0387" definition-exists="false" ipc-concordant="E21B33/035" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/0387</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Hydraulic stab connectors</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B33/0387</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/035</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/035</class-ref> and <class-ref scheme="cpc">E21B33/0387</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/04" definition-exists="false" ipc-concordant="E21B33/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Casing heads</text></title-part><title-part><text>Suspending casings or tubings in well heads </text><reference><text>setting of casings in wells <class-ref scheme="cpc">E21B43/10</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/0407" definition-exists="false" ipc-concordant="E21B33/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/0407</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with a suspended electrical cable</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/0415" definition-exists="false" ipc-concordant="E21B33/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/0415</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>rotating or floating support for tubing or casing hanger</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/0422" definition-exists="true" ipc-concordant="E21B33/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/0422</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>a suspended tubing or casing being gripped by a slip or an internally serrated member</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B33/0422</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B33/0353</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/0422</class-ref> and <class-ref scheme="cpc">E21B33/0353</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/043" definition-exists="false" ipc-concordant="E21B33/043" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/043</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>specially adapted for underwater well heads </text><reference><CPC-specific-text><text><class-ref scheme="cpc">E21B33/0407</class-ref>,</text></CPC-specific-text><text> <class-ref scheme="cpc">E21B33/047</class-ref> take precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/047" definition-exists="false" ipc-concordant="E21B33/047" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/047</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>for plural tubing strings</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/05" definition-exists="false" ipc-concordant="E21B33/05" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/05</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Cementing-heads, e.g. having provision for introducing cementing plugs</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/06" definition-exists="true" ipc-concordant="E21B33/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/06</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Blow-out preventers </text><CPC-specific-text><text>, i.e. apparatus closing around a drill pipe, e.g. annular blow-out preventers </text><reference><text>rotating blow-out preventers <class-ref scheme="cpc">E21B33/085</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/061" definition-exists="false" ipc-concordant="E21B33/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/061</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Ram-type blow-out preventers, e.g. with pivoting rams</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B33/062" definition-exists="false" ipc-concordant="E21B33/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/062</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with sliding rams</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="13" additional-only="false" sort-key="E21B33/063" definition-exists="true" ipc-concordant="E21B33/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/063</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>for shearing drill pipes </text><reference><text>cutting of wireline <class-ref scheme="cpc">E21B29/04</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/064" definition-exists="false" ipc-concordant="E21B33/064" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/064</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>specially adapted for underwater well heads </text><reference><CPC-specific-text><text>control systems for submerged well-heads <class-ref scheme="cpc">E21B33/0355</class-ref>;</text></CPC-specific-text><text> connectors therefor <class-ref scheme="cpc">E21B33/038</class-ref></text></reference></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/068" definition-exists="false" ipc-concordant="E21B33/068" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/068</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>having provision for introducing objects or fluids into, or removing objects from, wells </text><reference><text>cementing heads <class-ref scheme="cpc">E21B33/05</class-ref> </text><CPC-specific-text><text>; wipers, oil savers <class-ref scheme="cpc">E21B33/08</class-ref></text></CPC-specific-text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/072" definition-exists="false" ipc-concordant="E21B33/072" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/072</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>for cable-operated tools </text><reference><text><class-ref scheme="cpc">E21B33/076</class-ref> takes precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/076" definition-exists="false" ipc-concordant="E21B33/076" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/076</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>specially adapted for underwater installations</text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B33/08" definition-exists="false" ipc-concordant="E21B33/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Wipers</text></title-part><title-part><text>Oil savers</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/085" definition-exists="false" ipc-concordant="E21B33/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/085</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Rotatable packing means, e.g. rotating blow-out preventers</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B33/10" definition-exists="false" ipc-concordant="E21B33/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>in the borehole </text><CPC-specific-text><reference><text>sealing the junction between main bore and laterals <class-ref scheme="cpc">E21B41/0042</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B33/12" definition-exists="true" ipc-concordant="E21B33/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/12</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Packers</text></title-part><title-part><text>Plugs </text><reference><text>used for cementing <class-ref scheme="cpc">E21B33/134</class-ref>, <class-ref scheme="cpc">E21B33/16</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/1204" definition-exists="false" ipc-concordant="E21B33/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1204</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>permanent; drillable</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/1208" definition-exists="false" ipc-concordant="E21B33/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1208</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>characterised by the construction of the sealing or packing means </text><reference><text><class-ref scheme="cpc">E21B33/1277</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1212" definition-exists="false" ipc-concordant="E21B33/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1212</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>including a metal-to-metal seal element</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1216" definition-exists="false" ipc-concordant="E21B33/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1216</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Anti-extrusion means, e.g. means to prevent cold flow of rubber packing</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/122" definition-exists="false" ipc-concordant="E21B33/122" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/122</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Multiple string packers</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/124" definition-exists="false" ipc-concordant="E21B33/124" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/124</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Units with longitudinally-spaced plugs for isolating the intermediate space</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1243" definition-exists="false" ipc-concordant="E21B33/124" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1243</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with inflatable sleeves</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B33/1246" definition-exists="false" ipc-concordant="E21B33/124" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1246</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>inflated by down-hole pumping means operated by a pipe string</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/126" definition-exists="false" ipc-concordant="E21B33/126" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/126</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with fluid-pressure-operated elastic cup or skirt </text><reference><text><class-ref scheme="cpc">E21B33/122</class-ref>, <class-ref scheme="cpc">E21B33/124</class-ref> take precedence</text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1265" definition-exists="false" ipc-concordant="E21B33/126" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1265</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with mechanical slips</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/127" definition-exists="false" ipc-concordant="E21B33/127" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/127</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with inflatable sleeve </text><reference><text><class-ref scheme="cpc">E21B33/122</class-ref>, <class-ref scheme="cpc">E21B33/124</class-ref> take precedence</text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1272" definition-exists="false" ipc-concordant="E21B33/127" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1272</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>inflated by down-hole pumping means operated by a pipe string</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1275" definition-exists="false" ipc-concordant="E21B33/127" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1275</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>inflated by down-hole pumping means operated by a down-hole drive</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1277" definition-exists="false" ipc-concordant="E21B33/127" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1277</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>characterised by the construction or fixation of the sleeve</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/128" definition-exists="false" ipc-concordant="E21B33/128" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/128</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>with a member expanded radially by axial pressure </text><reference><text><class-ref scheme="cpc">E21B33/122</class-ref>, <class-ref scheme="cpc">E21B33/124</class-ref> </text><CPC-specific-text><text>, <class-ref scheme="cpc">E21B33/129</class-ref></text></CPC-specific-text><text> take precedence </text><CPC-specific-text><text>; characterised by the construction of the sealing means <class-ref scheme="cpc">E21B33/1208</class-ref></text></CPC-specific-text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1285" definition-exists="false" ipc-concordant="E21B33/128" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1285</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>by fluid pressure</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/129" definition-exists="false" ipc-concordant="E21B33/129" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/129</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>with mechanical slips for hooking into the casing </text><reference><text><class-ref scheme="cpc">E21B33/122</class-ref>, <class-ref scheme="cpc">E21B33/124</class-ref> take precedence</text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1291" definition-exists="false" ipc-concordant="E21B33/129" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1291</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>anchor set by wedge or cam in combination with frictional effect, using so-called drag-blocks </text><reference><text><class-ref scheme="cpc">E21B33/1295</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B33/1292" definition-exists="false" ipc-concordant="E21B33/129" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1292</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with means for anchoring against downward and upward movement</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1293" definition-exists="false" ipc-concordant="E21B33/129" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1293</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with means for anchoring against downward and upward movement </text><reference><text><class-ref scheme="cpc">E21B33/1291</class-ref>, <class-ref scheme="cpc">E21B33/1295</class-ref> take precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1294" definition-exists="false" ipc-concordant="E21B33/129" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1294</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>characterised by a valve, e.g. a by-pass valve</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/1295" definition-exists="false" ipc-concordant="E21B33/1295" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/1295</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>actuated by fluid pressure</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B33/12955" definition-exists="false" ipc-concordant="E21B33/1295" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/12955</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using drag blocks frictionally engaging the inner wall of the well</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B33/13" definition-exists="true" ipc-concordant="E21B33/13" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/13</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Methods or devices for cementing, for plugging holes, crevices, or the like </text><reference><text>dump bailers <class-ref scheme="cpc">E21B27/02</class-ref>; chemical compositions therefor <class-ref scheme="cpc">C09K8/00</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/134" definition-exists="true" ipc-concordant="E21B33/134" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/134</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Bridging plugs</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/136" definition-exists="false" ipc-concordant="E21B33/136" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/136</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Baskets, e.g. of umbrella type</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/138" definition-exists="true" ipc-concordant="E21B33/138" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/138</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Plastering the borehole wall</text></title-part><title-part><text>Injecting into the formation </text><CPC-specific-text><reference><text>packers <class-ref scheme="cpc">E21B33/12</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B33/14" definition-exists="true" ipc-concordant="E21B33/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/14</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>for cementing casings into boreholes </text><CPC-specific-text><reference><text>control of cementation quality or level <class-ref scheme="cpc">E21B47/005</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/143" definition-exists="false" ipc-concordant="E21B33/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/143</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>for underwater installations</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/146" definition-exists="false" ipc-concordant="E21B33/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B33/146</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Stage cementing, i.e. discharging cement from casing at different levels</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B33/16" definition-exists="false" ipc-concordant="E21B33/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/16</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using plugs for isolating cement charge</text></title-part><title-part><text>Plugs therefor </text><CPC-specific-text><reference><text>stage cementing <class-ref scheme="cpc">E21B33/146</class-ref>; spacer compositions <class-ref scheme="cpc">C09K8/424</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B33/16</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B33/165</class-ref> and <class-ref scheme="cpc">E21B33/167</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/16</class-ref>, <class-ref scheme="cpc">E21B33/165</class-ref>, and <class-ref scheme="cpc">E21B33/167</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B33/165" definition-exists="false" ipc-concordant="E21B33/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/165</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Cementing plugs specially adapted for being released down-hole </text><reference><text>cementing heads <class-ref scheme="cpc">E21B33/05</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B33/165</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/16</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/16</class-ref> and <class-ref scheme="cpc">E21B33/165</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B33/167" definition-exists="false" ipc-concordant="E21B33/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B33/167</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Cementing plugs provided with anti-rotation mechanisms, e.g. for easier drill-out</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B33/167</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/16</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/16</class-ref> and <class-ref scheme="cpc">E21B33/167</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B34/00" definition-exists="true" ipc-concordant="E21B34/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B34/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Valve arrangements for boreholes or wells </text><reference><text>in drilling fluid circulation systems <class-ref scheme="cpc">E21B21/10</class-ref>; blow-out preventers <class-ref scheme="cpc">E21B33/06</class-ref>; oil flow regulating apparatus <class-ref scheme="cpc">E21B43/12</class-ref>; valves in general <class-ref scheme="cpc">F16K</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B34/02" definition-exists="false" ipc-concordant="E21B34/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B34/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>in well heads</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B34/02</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B34/025</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B34/02</class-ref> and <class-ref scheme="cpc">E21B34/025</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B34/025" definition-exists="false" ipc-concordant="E21B34/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B34/025</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Chokes or valves in wellheads and sub-sea wellheads for variably regulating fluid flow</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B34/025</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B34/02</class-ref>, <class-ref scheme="cpc">E21B34/04</class-ref>, and <class-ref scheme="cpc">E21B34/045</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B34/04" definition-exists="false" ipc-concordant="E21B34/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B34/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>in underwater well heads</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B34/04</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B34/025</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B34/04</class-ref> and <class-ref scheme="cpc">E21B34/025</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B34/045" definition-exists="false" ipc-concordant="E21B34/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B34/045</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>adapted to be lowered on a tubular string into position within a blow-out preventer stack, e.g. so-called test trees</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B34/045</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B34/025</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B34/045</class-ref> and <class-ref scheme="cpc">E21B34/025</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B34/06" definition-exists="false" ipc-concordant="E21B34/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>in wells</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B34/063" definition-exists="false" ipc-concordant="E21B34/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/063</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Valve or closure with destructible element, e.g. frangible disc </text><reference><text><class-ref scheme="cpc">E21B34/103</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B34/066" definition-exists="false" ipc-concordant="E21B34/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/066</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>electrically actuated</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B34/08" definition-exists="false" ipc-concordant="E21B34/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>responsive to flow or pressure of the fluid obtained </text><reference><text><class-ref scheme="cpc">E21B34/10</class-ref> takes precedence</text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B34/085" definition-exists="false" ipc-concordant="E21B34/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/085</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with time-delay systems, e.g. hydraulic impedance mechanisms</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B34/10" definition-exists="false" ipc-concordant="E21B34/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B34/10</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>operated by control fluid supplied from outside the borehole </text><reference><CPC-specific-text><text>by a dropped ball or piston <class-ref scheme="cpc">E21B34/142</class-ref>;</text></CPC-specific-text><text> control means being outside the borehole <class-ref scheme="cpc">E21B34/16</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B34/101" definition-exists="false" ipc-concordant="E21B34/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/101</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with means for equalizing fluid pressure above and below the valve</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B34/102" definition-exists="false" ipc-concordant="E21B34/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-05-01" status="published"><classification-symbol>E21B34/102</classification-symbol><class-title date-revised="2017-05-01"><title-part><CPC-specific-text><text>with means for locking the closing element in open or closed position </text><reference><text><class-ref scheme="cpc">E21B34/105</class-ref> and <class-ref scheme="cpc">E21B34/108</class-ref> take precedence</text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B34/103" definition-exists="false" ipc-concordant="E21B34/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/103</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with a shear pin</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B34/105" definition-exists="false" ipc-concordant="E21B34/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/105</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>retrievable, e.g. wire line retrievable, i.e. with an element which can be landed into a landing-nipple provided with a passage for control fluid</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B34/106" definition-exists="false" ipc-concordant="E21B34/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/106</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the retrievable element being a secondary control fluid actuated valve landed into the bore of a first inoperative control fluid actuated valve</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B34/107" definition-exists="false" ipc-concordant="E21B34/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/107</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the retrievable element being an operating or controlling means retrievable separately from the closure member, e.g. pilot valve landed into a side pocket </text><reference><text><class-ref scheme="cpc">E21B34/106</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B34/108" definition-exists="false" ipc-concordant="E21B34/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/108</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with time delay systems, e.g. hydraulic impedance mechanisms</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B34/12" definition-exists="false" ipc-concordant="E21B34/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/12</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>operated by movement of casings or tubings</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B34/125" definition-exists="false" ipc-concordant="E21B34/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B34/125</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with time delay systems, e.g. hydraulic impedance mechanisms</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B34/14" definition-exists="false" ipc-concordant="E21B34/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B34/14</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools </text><CPC-specific-text><reference><text><class-ref scheme="cpc">E21B34/066</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B34/14</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B34/142</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B34/14</class-ref> and <class-ref scheme="cpc">E21B34/142</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B34/142" definition-exists="false" ipc-concordant="E21B34/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B34/142</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>unsupported or free-falling elements, e.g. balls, plugs, darts or pistons</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B34/142</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B23/04</class-ref> and <class-ref scheme="cpc">E21B34/14</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B23/04</class-ref>, <class-ref scheme="cpc">E21B34/14</class-ref>, and <class-ref scheme="cpc">E21B34/142</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B34/16" definition-exists="false" ipc-concordant="E21B34/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B34/16</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Control means therefor being outside the borehole </text><CPC-specific-text><reference><text>control systems for submerged well heads <class-ref scheme="cpc">E21B33/0355</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B35/00" definition-exists="true" ipc-concordant="E21B35/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B35/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Methods or apparatus for preventing or extinguishing fires </text><reference><text>cutting or deforming pipes to control fluid flow <class-ref scheme="cpc">E21B29/08</class-ref>; controlling flow of fluid to or in wells <class-ref scheme="cpc">E21B43/12</class-ref>; fire fighting in general <class-ref scheme="cpc">A62C</class-ref>, <class-ref scheme="cpc">A62D</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B36/00" definition-exists="true" ipc-concordant="E21B36/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B36/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Heating, cooling, insulating arrangements for boreholes or wells, e.g. for use in permafrost zones </text><reference><text>drilling by use of heat <class-ref scheme="cpc">E21B7/14</class-ref>; secondary recovery methods using heat <class-ref scheme="cpc">E21B43/24</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B36/001" definition-exists="false" ipc-concordant="E21B36/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B36/001</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Cooling arrangements</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B36/003" definition-exists="false" ipc-concordant="E21B36/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B36/003</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Insulating arrangements</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B36/005" definition-exists="false" ipc-concordant="E21B36/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B36/005</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Heater surrounding production tube</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B36/006" definition-exists="false" ipc-concordant="E21B36/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B36/006</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Combined heating and pumping means</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B36/008" definition-exists="false" ipc-concordant="E21B36/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B36/008</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using chemical heat generating means</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B36/02" definition-exists="false" ipc-concordant="E21B36/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B36/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using burners</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B36/025" definition-exists="false" ipc-concordant="E21B36/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B36/025</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>the burners being above ground or outside the bore hole</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B36/04" definition-exists="false" ipc-concordant="E21B36/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B36/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using electrical heaters</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B37/00" definition-exists="true" ipc-concordant="E21B37/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B37/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Methods or apparatus for cleaning boreholes or wells </text><reference><text><class-ref scheme="cpc">E21B21/00</class-ref> takes precedence; </text><CPC-specific-text><text>bailers <class-ref scheme="cpc">E21B27/00</class-ref>;</text></CPC-specific-text><text> cleaning pipes in general <class-ref scheme="cpc">B08B9/02</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B37/02" definition-exists="false" ipc-concordant="E21B37/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B37/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Scrapers specially adapted therefor</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B37/04" definition-exists="true" ipc-concordant="E21B37/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B37/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>operated by fluid pressure, e.g. free-piston scrapers </text><reference><text>operating other tools by fluid pressure <class-ref scheme="cpc">E21B23/08</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B37/045" definition-exists="false" ipc-concordant="E21B37/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B37/045</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Free-piston scrapers</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B37/06" definition-exists="false" ipc-concordant="E21B37/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B37/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using chemical means for preventing, limiting </text><CPC-specific-text><text>or eliminating</text></CPC-specific-text><text> the deposition of paraffins or like substances </text><reference><text>chemical compositions therefor <class-ref scheme="cpc">C09K8/52</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B37/08" definition-exists="false" ipc-concordant="E21B37/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B37/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>cleaning <u>in situ</u> of down-hole filters, screens, </text><CPC-specific-text><text>e.g. casing perforations,</text></CPC-specific-text><text> or gravel packs </text><reference><text><class-ref scheme="cpc">E21B37/06</class-ref> takes precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B37/10" definition-exists="true" ipc-concordant="E21B37/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B37/10</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Well swabs</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B40/00" definition-exists="true" ipc-concordant="E21B40/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B40/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Tubing catchers, automatically arresting the fall of oil-well tubing </text><CPC-specific-text><reference><text>preventing small objects from falling into the borehole <class-ref scheme="cpc">E21B41/0021</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B40/00</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B40/001</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B40/00</class-ref> and <class-ref scheme="cpc">E21B40/001</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B40/001" definition-exists="false" ipc-concordant="E21B40/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B40/001</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>in the borehole </text><reference><text>anchoring tools in the borehole <class-ref scheme="cpc">E21B23/01</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B40/001</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B40/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B40/00</class-ref> and <class-ref scheme="cpc">E21B40/001</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B41/00" definition-exists="true" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B41/00</classification-symbol><class-title date-revised="2016-05-01"><title-part><text>Equipment or details not covered by groups <class-ref scheme="cpc">E21B15/00</class-ref>&#160;-&#160;<class-ref scheme="cpc">E21B40/00</class-ref></text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B41/00</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B41/0092</class-ref>.<br/>Group <class-ref scheme="cpc">E21B41/00</class-ref> is also impacted by reclassification into group <class-ref scheme="cpc">E21B41/0099</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B41/0092</class-ref>, <class-ref scheme="cpc">E21B41/00</class-ref>, and <class-ref scheme="cpc">E21B41/0099</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/0007" definition-exists="false" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/0007</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>for underwater installations </text><reference><text><class-ref scheme="cpc">E21B41/005</class-ref>, <class-ref scheme="cpc">E21B41/04</class-ref>, <class-ref scheme="cpc">E21B41/06</class-ref>, <class-ref scheme="cpc">E21B41/08</class-ref>, <class-ref scheme="cpc">E21B41/10</class-ref> take precedence</text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B41/0014" definition-exists="false" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/0014</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Underwater well locating or reentry systems</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/0021" definition-exists="false" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/0021</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Safety devices, e.g. for preventing small objects from falling into the borehole</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/0035" definition-exists="true" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B41/0035</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Apparatus or methods for multilateral well technology, e.g. for the completion of or workover on wells with one or more lateral branches</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B41/0042" definition-exists="false" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/0042</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>characterised by sealing the junction between a lateral and a main bore</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/005" definition-exists="true" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B41/005</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Waste disposal systems</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B41/0057" definition-exists="false" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/0057</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Disposal of a fluid by injection into a subterranean formation</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B41/0064" definition-exists="false" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/0064</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Carbon dioxide sequestration </text><reference><text>storing fluids in porous layers <class-ref scheme="cpc">B65G5/005</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B41/0071" definition-exists="false" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/0071</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Adaptation of flares, e.g. arrangements of flares in offshore installations </text><reference><text>flares of waste gases or noxious gases <class-ref scheme="cpc">F23G7/08</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/0078" definition-exists="true" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B41/0078</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Nozzles used in boreholes </text><reference><text>drilling by liquid or gas jets <class-ref scheme="cpc">E21B7/18</class-ref>; drill bits with nozzles <class-ref scheme="cpc">E21B10/60</class-ref>; perforators using direct fluid action <class-ref scheme="cpc">E21B43/114</class-ref>; obtaining a slurry of minerals using nozzles <class-ref scheme="cpc">E21B43/29</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/0085" definition-exists="true" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B41/0085</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Adaptations of electric power generating means for use in boreholes</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/0092" definition-exists="false" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="frozen"><classification-symbol>E21B41/0092</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Methods relating to program engineering, design or optimisation</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B41/0092</class-ref> is no longer used for the classification of documents as of <reclassification-date>2020-05-01</reclassification-date>.<br/>The content of this group is being reclassified into groups <class-ref scheme="cpc">E21B41/00</class-ref>, <class-ref scheme="cpc">E21B43/00</class-ref>, <class-ref scheme="cpc">E21B43/16</class-ref>, and <class-ref scheme="cpc">G06Q10/06</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/0099" definition-exists="false" ipc-concordant="E21B41/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B41/0099</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>specially adapted for drilling for or production of natural hydrate or clathrate gas reservoirs; Drilling through or monitoring of formations containing gas hydrates or clathrates</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B41/0099</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B41/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B41/00</class-ref> and <class-ref scheme="cpc">E21B41/0099</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/02" definition-exists="true" ipc-concordant="E21B41/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text><u>in situ</u> inhibition of corrosion in boreholes or wells </text><reference><text>dump bailers <class-ref scheme="cpc">E21B27/02</class-ref>; chemical compositions therefor <class-ref scheme="cpc">C09K8/54</class-ref>; inhibiting corrosion in general <class-ref scheme="cpc">C23F</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/04" definition-exists="false" ipc-concordant="E21B41/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Manipulators for underwater operations, e.g. temporarily connected to well heads </text><reference><text>manipulators in general <class-ref scheme="cpc">B25J</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/06" definition-exists="false" ipc-concordant="E21B41/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Work chambers for underwater operations, e.g. temporarily connected to well heads </text><reference><text>in general <class-ref scheme="cpc">B63C11/00</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/08" definition-exists="false" ipc-concordant="E21B41/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-08-01" status="published"><classification-symbol>E21B41/08</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Underwater guide bases, e.g. drilling templates</text></title-part><title-part><text>Levelling thereof</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B41/10" definition-exists="false" ipc-concordant="E21B41/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B41/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Guide posts, e.g. releasable</text></title-part><title-part><text>Attaching guide lines to underwater guide bases</text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="true" level="6" additional-only="false" sort-key="E21B43/00" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Obtaining fluids from wells</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B43/00" definition-exists="true" ipc-concordant="E21B43/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells </text><reference><text>applicable only to water <class-ref scheme="cpc">E03B</class-ref>; obtaining oil-bearing deposits or soluble or meltable materials by mining techniques <class-ref scheme="cpc">E21C41/00</class-ref>; pumps <class-ref scheme="cpc">F04</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/00</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B41/0092</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B41/0092</class-ref> and <class-ref scheme="cpc">E21B43/00</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/003" definition-exists="true" ipc-concordant="E21B43/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/003</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Vibrating earth formations</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/006" definition-exists="true" ipc-concordant="E21B43/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/006</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Production of coal-bed methane </text><reference><text><class-ref scheme="cpc">E21B43/243</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/01" definition-exists="true" ipc-concordant="E21B43/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/01</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>specially adapted for obtaining from underwater installations </text><reference><text>underwater well heads <class-ref scheme="cpc">E21B33/035</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/0107" definition-exists="false" ipc-concordant="E21B43/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/0107</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Connecting of flow lines to offshore structures </text><reference><text><class-ref scheme="cpc">E21B43/013</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/0122" definition-exists="false" ipc-concordant="E21B43/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/0122</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Collecting oil or the like from a submerged leakage </text><reference><text>cleaning or keeping clear the surface of open water from oil or the like <class-ref scheme="cpc">E02B15/04</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/013" definition-exists="false" ipc-concordant="E21B43/013" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-08-01" status="published"><classification-symbol>E21B43/013</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>Connecting a production flow line to an underwater well head</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/0135" definition-exists="false" ipc-concordant="E21B43/013" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/0135</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using a pulling cable</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/017" definition-exists="false" ipc-concordant="E21B43/017" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/017</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Production satellite stations, i.e. underwater installations comprising a plurality of satellite well heads connected to a central station </text><reference><text>underwater separating arrangements <class-ref scheme="cpc">E21B43/36</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/017</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/0175</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/017</class-ref> and <class-ref scheme="cpc">E21B43/0175</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/0175" definition-exists="false" ipc-concordant="E21B43/017" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/0175</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Hydraulic schemes for production manifolds</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/0175</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B43/017</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/017</class-ref> and <class-ref scheme="cpc">E21B43/0175</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/02" definition-exists="true" ipc-concordant="E21B43/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/02</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Subsoil filtering </text><reference><text><class-ref scheme="cpc">E21B43/11</class-ref> takes precedence; chemical compositions for consolidating loose sand or the like around wells <class-ref scheme="cpc">C09K8/56</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/025" definition-exists="true" ipc-concordant="E21B43/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/025</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Consolidation of loose sand or the like round the wells without excessively decreasing the permeability thereof</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/04" definition-exists="false" ipc-concordant="E21B43/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/04</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Gravelling of wells</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/045" definition-exists="false" ipc-concordant="E21B43/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/045</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Crossover tools</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/08" definition-exists="true" ipc-concordant="E21B43/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/08</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Screens or liners </text><CPC-specific-text><reference><text>expandable screens or liners <class-ref scheme="cpc">E21B43/108</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/082" definition-exists="false" ipc-concordant="E21B43/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/082</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Screens comprising porous materials, e.g. prepacked screens</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/084" definition-exists="false" ipc-concordant="E21B43/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/084</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Screens comprising woven materials, e.g. mesh or cloth</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/086" definition-exists="false" ipc-concordant="E21B43/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/086</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Screens with preformed openings, e.g. slotted liners </text><reference><text>comprising porous materials <class-ref scheme="cpc">E21B43/082</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/088" definition-exists="false" ipc-concordant="E21B43/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/088</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Wire screens </text><reference><text>comprising porous materials <class-ref scheme="cpc">E21B43/082</class-ref>; comprising woven materials <class-ref scheme="cpc">E21B43/084</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/10" definition-exists="true" ipc-concordant="E21B43/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Setting of casings, screens, liners </text><CPC-specific-text><text>or the like</text></CPC-specific-text><text> in wells </text><reference><text>driving or forcing casings into boreholes, simultaneously drilling and casing boreholes <class-ref scheme="cpc">E21B7/20</class-ref>; setting of tools, packers or the like <class-ref scheme="cpc">E21B23/00</class-ref>; suspending casings in well heads <class-ref scheme="cpc">E21B33/04</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/101" definition-exists="false" ipc-concordant="E21B43/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/101</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>for underwater installations</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/103" definition-exists="false" ipc-concordant="E21B43/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/103</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>of expandable casings, screens, liners, or the like</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/105" definition-exists="false" ipc-concordant="E21B43/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/105</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Expanding tools specially adapted therefor</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/106" definition-exists="false" ipc-concordant="E21B43/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/106</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Couplings or joints therefor</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/108" definition-exists="false" ipc-concordant="E21B43/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/108</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Expandable screens or perforated liners</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/11" definition-exists="true" ipc-concordant="E21B43/11" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/11</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Perforators</text></title-part><title-part><text>Permeators</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/112" definition-exists="false" ipc-concordant="E21B43/112" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-01-01" status="published"><classification-symbol>E21B43/112</classification-symbol><class-title date-revised="2017-01-01"><title-part><text>Perforators with extendable perforating members, e.g. actuated by fluid means</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/114" definition-exists="false" ipc-concordant="E21B43/114" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/114</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Perforators using direct fluid action </text><CPC-specific-text><text>on the wall to be perforated</text></CPC-specific-text><text>, e.g. abrasive jets</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/116" definition-exists="true" ipc-concordant="E21B43/116" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/116</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Gun or shaped-charge perforators</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/117" definition-exists="false" ipc-concordant="E21B43/117" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/117</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Shaped-charge perforators </text><reference><text><class-ref scheme="cpc">E21B43/118</class-ref> takes precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/118" definition-exists="false" ipc-concordant="E21B43/118" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/118</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>characterised by lowering in vertical position and subsequent tilting to operating position</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/1185" definition-exists="false" ipc-concordant="E21B43/1185" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/1185</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Ignition systems</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/11852" definition-exists="false" ipc-concordant="E21B43/1185" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/11852</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>hydraulically actuated</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/11855" definition-exists="false" ipc-concordant="E21B43/1185" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/11855</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>mechanically actuated, e.g. by movement of a wireline or a drop-bar </text><reference><text><class-ref scheme="cpc">E21B43/11852</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/11857" definition-exists="false" ipc-concordant="E21B43/1185" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/11857</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>firing indication systems</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/119" definition-exists="false" ipc-concordant="E21B43/119" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/119</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Details, e.g. for locating perforating place or direction</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/119</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/1193</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/119</class-ref> and <class-ref scheme="cpc">E21B43/1193</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/1193" definition-exists="true" ipc-concordant="E21B43/119" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/1193</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Dropping perforation guns after gun actuation</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/1193</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B43/119</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/119</class-ref> and <class-ref scheme="cpc">E21B43/1193</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/1195" definition-exists="false" ipc-concordant="E21B43/119" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/1195</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Replacement of drilling mud; decrease of undesirable shock waves</text></CPC-specific-text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/12" definition-exists="true" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/12</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Methods or apparatus for controlling the flow of the obtained fluid to or in wells </text><reference><text><class-ref scheme="cpc">E21B43/25</class-ref> takes precedence; valve arrangements <class-ref scheme="cpc">E21B34/00</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/121" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/121</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Lifting well fluids </text><reference><text>monitoring of down-hole pump systems <class-ref scheme="cpc">E21B47/008</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/121</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/13</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/121</class-ref> and <class-ref scheme="cpc">E21B43/13</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/122" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/122</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Gas lift</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/122</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/13</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/122</class-ref> and <class-ref scheme="cpc">E21B43/13</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/123" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/123</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Gas lift valves</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/123</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B43/1235</class-ref> and <class-ref scheme="cpc">E21B43/13</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/123</class-ref>, <class-ref scheme="cpc">E21B43/1235</class-ref>, and <class-ref scheme="cpc">E21B43/13</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B43/1235" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/1235</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>characterised by electromagnetic actuation</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/1235</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B43/123</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/123</class-ref> and <class-ref scheme="cpc">E21B43/1235</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/124" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/124</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Adaptation of jet-pump systems</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/124</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/13</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/124</class-ref> and <class-ref scheme="cpc">E21B43/13</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/126" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/126</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Adaptations of down-hole pump systems powered by drives outside the borehole, e.g. by a rotary or oscillating drive </text><reference><text>powered by fluid <class-ref scheme="cpc">E21B43/129</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/126</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/13</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/126</class-ref> and <class-ref scheme="cpc">E21B43/13</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/127" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/127</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Adaptations of walking-beam pump systems</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/127</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/13</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/127</class-ref> and <class-ref scheme="cpc">E21B43/13</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/128" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/128</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Adaptation of pump systems with down-hole electric drives</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/128</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/13</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/128</class-ref> and <class-ref scheme="cpc">E21B43/13</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/129" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/129</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Adaptations of down-hole pump systems powered by fluid supplied from outside the borehole </text><reference><text>gas-lift <class-ref scheme="cpc">E21B43/122</class-ref>; jet pumps <class-ref scheme="cpc">E21B43/124</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/129</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/13</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/129</class-ref> and <class-ref scheme="cpc">E21B43/13</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/13" definition-exists="false" ipc-concordant="E21B43/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/13</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>specially adapted to dewatering of wells of gas producing reservoirs, e.g. methane producing coal beds</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/13</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B43/121</class-ref>, <class-ref scheme="cpc">E21B43/122</class-ref>, <class-ref scheme="cpc">E21B43/123</class-ref>, <class-ref scheme="cpc">E21B43/124</class-ref>, <class-ref scheme="cpc">E21B43/126</class-ref>, <class-ref scheme="cpc">E21B43/127</class-ref>, <class-ref scheme="cpc">E21B43/128</class-ref>, and <class-ref scheme="cpc">E21B43/129</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/14" definition-exists="false" ipc-concordant="E21B43/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/14</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Obtaining from a multiple-zone well</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/16" definition-exists="true" ipc-concordant="E21B43/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/16</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>Enhanced recovery methods for obtaining hydrocarbons </text><reference><text>fracturing <class-ref scheme="cpc">E21B43/26</class-ref>; obtaining slurry <class-ref scheme="cpc">E21B43/29</class-ref>; reclamation of contaminated soil <u>in situ</u> <class-ref scheme="cpc">B09C</class-ref> </text><CPC-specific-text><text>; chemical compositions therefor <class-ref scheme="cpc">C09K8/58</class-ref></text></CPC-specific-text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/16</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B41/0092</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B41/0092</class-ref> and <class-ref scheme="cpc">E21B43/16</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/162" definition-exists="false" ipc-concordant="E21B43/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/162</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Injecting fluid from longitudinally spaced locations in injection well</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/164" definition-exists="false" ipc-concordant="E21B43/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/164</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Injecting CO<sub>2</sub> or carbonated water </text><reference><text>in combination with organic material <class-ref scheme="cpc">C09K8/594</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/166" definition-exists="false" ipc-concordant="E21B43/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/166</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Injecting a gaseous medium; Injecting a gaseous medium and a liquid medium </text><reference><text>CO<sub>2</sub> injection <class-ref scheme="cpc">E21B43/164</class-ref>; steam injection <class-ref scheme="cpc">E21B43/24</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/168" definition-exists="false" ipc-concordant="E21B43/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/168</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Injecting a gaseous medium</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/17" definition-exists="false" ipc-concordant="E21B43/17" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/17</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Interconnecting two or more wells by fracturing or otherwise attacking the formation </text><reference><CPC-specific-text><text><class-ref scheme="cpc">E21B43/2405</class-ref>,</text></CPC-specific-text><text> <class-ref scheme="cpc">E21B43/247</class-ref> take precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/18" definition-exists="false" ipc-concordant="E21B43/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/18</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Repressuring or vacuum methods</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/20" definition-exists="false" ipc-concordant="E21B43/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/20</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Displacing by water</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/24" definition-exists="true" ipc-concordant="E21B43/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/24</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using heat, e.g. steam injection </text><reference><text>heating, cooling or insulating wells <class-ref scheme="cpc">E21B36/00</class-ref> </text><CPC-specific-text><text>; in combination with organic material <class-ref scheme="cpc">C09K8/592</class-ref></text></CPC-specific-text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/2401" definition-exists="false" ipc-concordant="E21B43/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/2401</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>by means of electricity</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/2403" definition-exists="true" ipc-concordant="E21B43/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/2403</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>by means of nuclear energy</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/2405" definition-exists="false" ipc-concordant="E21B43/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/2405</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>in association with fracturing or crevice forming processes </text><reference><text><class-ref scheme="cpc">E21B43/247</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/2406" definition-exists="false" ipc-concordant="E21B43/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/2406</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Steam assisted gravity drainage [SAGD]</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/2408" definition-exists="false" ipc-concordant="E21B43/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-08-01" status="published"><classification-symbol>E21B43/2408</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>SAGD in combination with other methods</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/241" definition-exists="false" ipc-concordant="E21B43/241" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/241</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>combined with solution mining of non-hydrocarbon minerals, e.g. solvent pyrolysis of oil shale</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/243" definition-exists="false" ipc-concordant="E21B43/243" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/243</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Combustion <u>in situ</u></text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/247" definition-exists="false" ipc-concordant="E21B43/247" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/247</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>in association with fracturing processes </text><CPC-specific-text><text>or crevice forming processes</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="12" additional-only="false" sort-key="E21B43/248" definition-exists="false" ipc-concordant="E21B43/248" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/248</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using explosives</text></title-part></class-title></classification-item></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/25" definition-exists="true" ipc-concordant="E21B43/25" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/25</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Methods for stimulating production </text><reference><text>dump bailers <class-ref scheme="cpc">E21B27/02</class-ref>; vibration generating arrangements <class-ref scheme="cpc">E21B28/00</class-ref>; </text><CPC-specific-text><text>by vibrating earth formations <class-ref scheme="cpc">E21B43/003</class-ref>;</text></CPC-specific-text><text> chemical compositions therefor <class-ref scheme="cpc">C09K8/60</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/255" definition-exists="false" ipc-concordant="E21B43/25" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/255</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>including the injection of a gaseous medium as treatment fluid into the formation</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/26" definition-exists="false" ipc-concordant="E21B43/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/26</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>by forming crevices or fractures </text><CPC-specific-text><reference><text>chemical compositions therefor <class-ref scheme="cpc">C09K8/62</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/26</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B43/2605</class-ref>, <class-ref scheme="cpc">E21B43/2607</class-ref>, and <class-ref scheme="cpc">E21B43/27</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/2605" definition-exists="false" ipc-concordant="E21B43/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/2605</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using gas or liquefied gas</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/2605</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B43/26</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/26</class-ref> and <class-ref scheme="cpc">E21B43/2605</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/2607" definition-exists="false" ipc-concordant="E21B43/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/2607</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Surface equipment specially adapted for fracturing operations</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/2607</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B43/26</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/26</class-ref> and <class-ref scheme="cpc">E21B43/2607</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/261" definition-exists="false" ipc-concordant="E21B43/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/261</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Separate steps of (1) cementing, plugging or consolidating and (2) fracturing or attacking the formation</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/263" definition-exists="false" ipc-concordant="E21B43/263" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-08-01" status="published"><classification-symbol>E21B43/263</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>using explosives </text><CPC-specific-text><reference><text>combustion <u>in situ</u> using explosives <class-ref scheme="cpc">E21B43/248</class-ref></text></reference></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B43/2635" definition-exists="true" ipc-concordant="E21B43/263" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/2635</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>by means of nuclear energy</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/267" definition-exists="false" ipc-concordant="E21B43/267" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/267</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>reinforcing fractures by propping </text><CPC-specific-text><reference><text>chemical compositions therefor <class-ref scheme="cpc">C09K8/80</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/27" definition-exists="false" ipc-concordant="E21B43/27" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/27</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by use of eroding chemicals, e.g. acids</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/27</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B43/26</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/26</class-ref> and <class-ref scheme="cpc">E21B43/27</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/28" definition-exists="true" ipc-concordant="E21B43/28" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/28</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent </text><reference><text><class-ref scheme="cpc">E21B43/241</class-ref> takes precedence</text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/281" definition-exists="true" ipc-concordant="E21B43/28" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/281</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using heat</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/283" definition-exists="false" ipc-concordant="E21B43/28" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/283</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>in association with a fracturing process</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/285" definition-exists="false" ipc-concordant="E21B43/285" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/285</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Melting minerals, e.g. sulfur </text><reference><text><class-ref scheme="cpc">E21B43/24</class-ref> takes precedence; heating, cooling or insulating arrangements for wells <class-ref scheme="cpc">E21B36/00</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/29" definition-exists="false" ipc-concordant="E21B43/29" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/29</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Obtaining a slurry of minerals, e.g. by using nozzles</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/292" definition-exists="false" ipc-concordant="E21B43/29" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/292</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>using steerable or laterally extendable nozzles</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/295" definition-exists="true" ipc-concordant="E21B43/295" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/295</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Gasification of minerals, e.g. for producing mixtures of combustible gases </text><reference><text><class-ref scheme="cpc">E21B43/243</class-ref> takes precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/30" definition-exists="false" ipc-concordant="E21B43/30" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/30</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Specific pattern of wells, e.g. optimizing the spacing of wells </text><reference><text>production satellite stations <class-ref scheme="cpc">E21B43/017</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/305" definition-exists="false" ipc-concordant="E21B43/30" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B43/305</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>comprising at least one inclined or horizontal well</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/32" definition-exists="false" ipc-concordant="E21B43/32" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/32</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Preventing gas- or water-coning phenomena, i.e. the formation of a conical column of gas or water around wells</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B43/34" definition-exists="true" ipc-concordant="E21B43/34" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/34</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Arrangements for separating materials produced by the well </text><reference><text>separating apparatus <u>per se</u>, <u>see</u> the relevant subclasses</text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/34</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/35</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/34</class-ref> and <class-ref scheme="cpc">E21B43/35</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/35" definition-exists="false" ipc-concordant="E21B43/34" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/35</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>specially adapted for separating solids </text><reference><text>down-hole drilling fluid separation systems <class-ref scheme="cpc">E21B21/002</class-ref>; separating solids from drilling fluids <class-ref scheme="cpc">E21B21/065</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B43/35</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B43/34</class-ref>, <class-ref scheme="cpc">E21B43/36</class-ref>, <class-ref scheme="cpc">E21B43/38</class-ref>, <class-ref scheme="cpc">E21B43/385</class-ref>, and <class-ref scheme="cpc">E21B43/40</class-ref>.<br/>All groups listed in this Warning should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/36" definition-exists="false" ipc-concordant="E21B43/36" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/36</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Underwater separating arrangements </text><reference><text><class-ref scheme="cpc">E21B43/38</class-ref> takes precedence</text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/36</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/35</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/36</class-ref> and <class-ref scheme="cpc">E21B43/35</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/38" definition-exists="false" ipc-concordant="E21B43/38" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/38</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>in the well</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/38</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/35</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/38</class-ref> and <class-ref scheme="cpc">E21B43/35</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B43/385" definition-exists="false" ipc-concordant="E21B43/38" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/385</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>by reinjecting the separated materials into an earth formation in the same well</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/385</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/35</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/385</class-ref> and <class-ref scheme="cpc">E21B43/35</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B43/40" definition-exists="false" ipc-concordant="E21B43/40" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B43/40</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Separation associated with re-injection of separated materials </text><CPC-specific-text><reference><text><class-ref scheme="cpc">E21B43/385</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B43/40</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B43/35</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B43/40</class-ref> and <class-ref scheme="cpc">E21B43/35</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="true" level="6" additional-only="false" sort-key="E21B44/00" date-revised="2013-01-01" status="published"><classification-symbol>E21B44/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Automatic control, surveying or testing</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B44/00" definition-exists="true" ipc-concordant="E21B44/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B44/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems </text><reference><text>for non-automatic drilling control, see the operation controlled; automatic feeding from rack and connecting of drilling pipes <class-ref scheme="cpc">E21B19/20</class-ref>; controlling pressure or flow of drilling fluid <class-ref scheme="cpc">E21B21/08</class-ref></text></reference></title-part><title-part><text>Systems specially adapted for monitoring a plurality of drilling variables or conditions </text><reference><text>means for transmitting measuring-signals from the well to the surface <class-ref scheme="cpc">E21B47/12</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B44/005" definition-exists="false" ipc-concordant="E21B44/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B44/005</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Below-ground automatic control systems</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B44/02" definition-exists="false" ipc-concordant="E21B44/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B44/02</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Automatic control of the tool feed </text><reference><CPC-specific-text><text><class-ref scheme="cpc">E21B44/005</class-ref>,</text></CPC-specific-text><text> <class-ref scheme="cpc">E21B44/10</class-ref> take precedence</text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B44/04" definition-exists="false" ipc-concordant="E21B44/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B44/04</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>in response to the torque of the drive </text><CPC-specific-text><text>; Measuring drilling torque </text><reference><text><class-ref scheme="cpc">E21B44/06</class-ref> takes precedence; measuring stresses in a well bore pipe <class-ref scheme="cpc">E21B47/007</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B44/06" definition-exists="false" ipc-concordant="E21B44/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B44/06</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>in response to the flow or pressure of the motive fluid of the drive</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B44/08" definition-exists="false" ipc-concordant="E21B44/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B44/08</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>in response to the amplitude of the movement of the percussion tool, e.g. jump or recoil</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B44/10" definition-exists="true" ipc-concordant="E21B44/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B44/10</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Arrangements for automatic stopping when the tool is lifted from the working face</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B45/00" definition-exists="false" ipc-concordant="E21B45/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B45/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Measuring the drilling time or rate of penetration</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B47/00" definition-exists="true" ipc-concordant="E21B47/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Survey of boreholes or wells </text><reference><text>monitoring pressure or flow of drilling fluid <class-ref scheme="cpc">E21B21/08</class-ref></text></reference></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B47/00</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B47/006</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/00</class-ref> and <class-ref scheme="cpc">E21B47/006</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/001" definition-exists="false" ipc-concordant="E21B47/001" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/001</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>for underwater installation</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/002" definition-exists="true" ipc-concordant="E21B47/002" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/002</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by visual inspection</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B47/002</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B47/0025</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/002</class-ref> and <class-ref scheme="cpc">E21B47/0025</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/0025" definition-exists="false" ipc-concordant="E21B47/002" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/0025</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>generating an image of the borehole wall using down-hole measurements, e.g. acoustic or electric</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B47/0025</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B47/002</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/002</class-ref> and <class-ref scheme="cpc">E21B47/0025</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/003" definition-exists="true" ipc-concordant="E21B47/003" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/003</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Determining well or borehole volumes </text><reference><text>determining depth <class-ref scheme="cpc">E21B47/04</class-ref>; diameter <class-ref scheme="cpc">E21B47/08</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/005" definition-exists="true" ipc-concordant="E21B47/005" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/005</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Monitoring or checking of cementation quality or level</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/006" definition-exists="false" ipc-concordant="E21B47/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/006</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Detection of corrosion or deposition of substances</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B47/006</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B47/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/00</class-ref> and <class-ref scheme="cpc">E21B47/006</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/007" definition-exists="false" ipc-concordant="E21B47/007" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/007</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Measuring stresses in a pipe string or casing </text><reference><text>for locating blocked portions of pipes <class-ref scheme="cpc">E21B47/09</class-ref></text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/008" definition-exists="false" ipc-concordant="E21B47/008" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/008</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Monitoring of down-hole pump systems, e.g. for the detection of &quot;pumped-off&quot; conditions</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/009" definition-exists="false" ipc-concordant="E21B47/009" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/009</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Monitoring of walking-beam pump systems</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/01" definition-exists="true" ipc-concordant="E21B47/01" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/01</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines</text></title-part><title-part><text>Protecting measuring instruments in boreholes against heat, shock, pressure or the like</text></title-part></class-title><notes-and-warnings date-revised="2013-01-01"><note type="note"><note-paragraph>Devices for both supporting and protecting measuring instruments are only classified in <class-ref scheme="cpc">E21B47/017</class-ref></note-paragraph></note><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B47/01</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B47/013</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/01</class-ref> and <class-ref scheme="cpc">E21B47/013</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/013" definition-exists="false" ipc-concordant="E21B47/013" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/013</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Devices specially adapted for supporting measuring instruments on drill bits</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B47/013</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B47/01</class-ref> and <class-ref scheme="cpc">E21B47/017</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/01</class-ref>, <class-ref scheme="cpc">E21B47/017</class-ref>, and <class-ref scheme="cpc">E21B47/013</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/017" definition-exists="true" ipc-concordant="E21B47/017" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/017</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Protecting measuring instruments</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B47/017</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B47/013</class-ref> and <class-ref scheme="cpc">E21B47/0175</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/017</class-ref>, <class-ref scheme="cpc">E21B47/013</class-ref>, and <class-ref scheme="cpc">E21B47/0175</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B47/0175" definition-exists="true" ipc-concordant="E21B47/017" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/0175</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Cooling arrangements</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B47/0175</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B47/017</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/017</class-ref> and <class-ref scheme="cpc">E21B47/0175</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/02" definition-exists="true" ipc-concordant="E21B47/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/02</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Determining slope or direction</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/022" definition-exists="false" ipc-concordant="E21B47/022" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/022</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>of the borehole, e.g. using geomagnetism</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B47/0224" definition-exists="false" ipc-concordant="E21B47/0224" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/0224</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using seismic or acoustic means</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B47/0228" definition-exists="false" ipc-concordant="E21B47/0228" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/0228</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using electromagnetic energy or detectors therefor</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B47/0232" definition-exists="false" ipc-concordant="E21B47/0232" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/0232</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>at least one of the energy sources or one of the detectors being located on or above the ground surface</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B47/0236" definition-exists="false" ipc-concordant="E21B47/0236" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/0236</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using a pendulum</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/024" definition-exists="false" ipc-concordant="E21B47/024" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B47/024</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>of devices in the borehole </text><reference><text><class-ref scheme="cpc">E21B47/022</class-ref> takes precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/026" definition-exists="true" ipc-concordant="E21B47/026" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/026</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>of penetrated ground layers</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/04" definition-exists="true" ipc-concordant="E21B47/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/04</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Measuring depth or liquid level</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/047" definition-exists="false" ipc-concordant="E21B47/047" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/047</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Liquid level </text><reference><text><class-ref scheme="cpc">E21B47/053</class-ref> takes precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/053" definition-exists="false" ipc-concordant="E21B47/053" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/053</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using radioactive markers</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/06" definition-exists="true" ipc-concordant="E21B47/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/06</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Measuring temperature or pressure</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/07" definition-exists="false" ipc-concordant="E21B47/07" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/07</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Temperature</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/08" definition-exists="true" ipc-concordant="E21B47/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/08</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Measuring diameters or related dimensions at the borehole</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/085" definition-exists="false" ipc-concordant="E21B47/085" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/085</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using radiant means, e.g. acoustic, radioactive or electromagnetic</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/09" definition-exists="true" ipc-concordant="E21B47/09" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/09</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Locating or determining the position of objects in boreholes or wells </text><CPC-specific-text><text>, e.g. the position of an extending arm</text></CPC-specific-text></title-part><title-part><text>Identifying the free or blocked portions of pipes</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/092" definition-exists="true" ipc-concordant="E21B47/092" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/092</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by detecting magnetic anomalies</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/095" definition-exists="false" ipc-concordant="E21B47/095" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/095</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by detecting an acoustic anomalies, e.g. using mud-pressure pulses</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/098" definition-exists="false" ipc-concordant="E21B47/098" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/098</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using impression packers, e.g. to detect recesses or perforations</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/10" definition-exists="true" ipc-concordant="E21B47/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/10</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Locating fluid leaks, intrusions or movements </text><CPC-specific-text><reference><text>using impression packers <class-ref scheme="cpc">E21B47/098</class-ref></text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B47/10</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B47/113</class-ref> and <class-ref scheme="cpc">E21B47/114</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/10</class-ref>, <class-ref scheme="cpc">E21B47/113</class-ref>, and <class-ref scheme="cpc">E21B47/114</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/103" definition-exists="false" ipc-concordant="E21B47/103" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/103</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using thermal measurements </text><CPC-specific-text><reference><text>measurement temperature <class-ref scheme="cpc">E21B47/07</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/107" definition-exists="false" ipc-concordant="E21B47/107" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/107</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using acoustic means</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/11" definition-exists="false" ipc-concordant="E21B47/11" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/11</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using tracers</text></title-part><title-part><text>using radioactivity</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B47/11</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B47/111</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/11</class-ref> and <class-ref scheme="cpc">E21B47/111</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B47/111" definition-exists="false" ipc-concordant="E21B47/11" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/111</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using radioactivity</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B47/111</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B47/11</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/11</class-ref> and <class-ref scheme="cpc">E21B47/111</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/113" definition-exists="false" ipc-concordant="E21B47/113" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/113</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using electrical indications</text></title-part><title-part><text>using light radiations</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B47/113</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B47/10</class-ref>.<br/>Group <class-ref scheme="cpc">E21B47/113</class-ref> is also impacted by reclassification into group <class-ref scheme="cpc">E21B47/114</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/10</class-ref>, <class-ref scheme="cpc">E21B47/113</class-ref>, and <class-ref scheme="cpc">E21B47/114</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B47/114" definition-exists="false" ipc-concordant="E21B47/113" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/114</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>using light radiation</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B47/114</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B47/10</class-ref> and <class-ref scheme="cpc">E21B47/113</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/10</class-ref>, <class-ref scheme="cpc">E21B47/113</class-ref>, and <class-ref scheme="cpc">E21B47/114</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/117" definition-exists="true" ipc-concordant="E21B47/117" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/117</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Detecting leaks, e.g. from tubing, by pressure testing</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/12" definition-exists="true" ipc-concordant="E21B47/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/12</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B47/12</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B47/138</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/12</class-ref> and <class-ref scheme="cpc">E21B47/138</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/125" definition-exists="true" ipc-concordant="E21B47/125" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/125</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using earth as an electrical conductor </text><reference><text><class-ref scheme="cpc">E21B47/13</class-ref> takes precedence</text></reference></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/13" definition-exists="true" ipc-concordant="E21B47/13" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/13</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by electromagnetic energy, e.g. radio frequency</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B47/135" definition-exists="true" ipc-concordant="E21B47/135" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/135</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using light waves, e.g. infrared or ultraviolet waves</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/138" definition-exists="false" ipc-concordant="E21B47/12" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/138</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Devices entrained in the flow of well-bore fluid for transmitting data, control or actuation signals</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B47/138</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B47/12</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B47/12</class-ref> and <class-ref scheme="cpc">E21B47/138</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B47/14" definition-exists="false" ipc-concordant="E21B47/14" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B47/14</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using acoustic waves</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B47/16" definition-exists="false" ipc-concordant="E21B47/16" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-08-01" status="published"><classification-symbol>E21B47/16</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>through the drill string or casing </text><CPC-specific-text><text>, e.g. by torsional acoustic waves</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B47/18" definition-exists="false" ipc-concordant="E21B47/18" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-08-01" status="published"><classification-symbol>E21B47/18</classification-symbol><class-title date-revised="2017-08-01"><title-part><text>through the well fluid </text><CPC-specific-text><text>, e.g. mud pressure pulse telemetry</text></CPC-specific-text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B47/20" definition-exists="false" ipc-concordant="E21B47/20" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/20</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by modulation of mud waves, e.g. by continuous modulation</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B47/22" definition-exists="false" ipc-concordant="E21B47/22" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/22</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by negative mud pulses using a pressure relieve valve between drill pipe and annulus</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="11" additional-only="false" sort-key="E21B47/24" definition-exists="false" ipc-concordant="E21B47/24" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/24</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>by positive mud pulses using a flow restricting valve within the drill pipe</text></title-part></class-title></classification-item></classification-item></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B47/26" definition-exists="true" ipc-concordant="E21B47/26" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B47/26</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Storing data down-hole, e.g. in a memory or on a record carrier</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="7" additional-only="false" sort-key="E21B49/00" definition-exists="true" ipc-concordant="E21B49/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B49/00</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>Testing the nature of borehole walls</text></title-part><title-part><text>Formation testing</text></title-part><title-part><text>Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells </text><reference><text>sampling in general <class-ref scheme="cpc">G01N1/00</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B49/001" definition-exists="false" ipc-concordant="E21B49/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B49/001</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>specially adapted for underwater installations</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B49/003" definition-exists="false" ipc-concordant="E21B49/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2017-08-01" status="published"><classification-symbol>E21B49/003</classification-symbol><class-title date-revised="2017-08-01"><title-part><CPC-specific-text><text>by analysing drilling variables or conditions </text><reference><text><class-ref scheme="cpc">E21B49/005</class-ref> takes precedence; systems specially adapted for monitoring a plurality of drilling variables or conditions <class-ref scheme="cpc">E21B44/00</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B49/005" definition-exists="true" ipc-concordant="E21B49/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/005</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Testing the nature of borehole walls or the formation by using drilling mud or cutting data</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B49/006" definition-exists="true" ipc-concordant="E21B49/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/006</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Measuring wall stresses in the borehole</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B49/008" definition-exists="true" ipc-concordant="E21B49/00" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/008</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>by injection test; by analysing pressure variations in an injection or production test, e.g. for estimating the skin factor </text><reference><text>measuring pressure <class-ref scheme="cpc">E21B47/06</class-ref></text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B49/02" definition-exists="true" ipc-concordant="E21B49/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B49/02</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>by mechanically taking samples of the soil </text><reference><text>apparatus for obtaining undisturbed cores <class-ref scheme="cpc">E21B25/00</class-ref>; investigation of foundation soil <u>in situ</u> <class-ref scheme="cpc">E02D1/00</class-ref></text></reference></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B49/025" definition-exists="true" ipc-concordant="E21B49/02" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/025</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>of underwater soil, e.g. with grab devices</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B49/04" definition-exists="true" ipc-concordant="E21B49/04" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/04</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using explosives in boreholes</text></title-part><title-part><text>using projectiles penetrating the wall</text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B49/06" definition-exists="false" ipc-concordant="E21B49/06" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/06</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>using side-wall drilling tools </text><CPC-specific-text><text>pressing</text></CPC-specific-text><text> or scrapers</text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="8" additional-only="false" sort-key="E21B49/08" definition-exists="true" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/08</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Obtaining fluid samples or testing fluids, in boreholes or wells</text></title-part></class-title>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B49/081" definition-exists="false" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/081</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with down-hole means for trapping a fluid sample </text><reference><text><class-ref scheme="cpc">E21B49/10</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B49/081</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B49/0813</class-ref> and <class-ref scheme="cpc">E21B49/0815</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B49/081</class-ref>, <class-ref scheme="cpc">E21B49/0813</class-ref>, and <class-ref scheme="cpc">E21B49/0815</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B49/0813" definition-exists="false" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/0813</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Sampling valve actuated by annulus pressure changes</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B49/0813</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B49/081</class-ref> and <class-ref scheme="cpc">E21B49/083</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B49/081</class-ref>, <class-ref scheme="cpc">E21B49/083</class-ref>, and <class-ref scheme="cpc">E21B49/0813</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B49/0815" definition-exists="false" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/0815</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>Sampling valve actuated by tubing pressure changes</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B49/0815</class-ref> is incomplete pending reclassification of documents from groups <class-ref scheme="cpc">E21B49/081</class-ref> and <class-ref scheme="cpc">E21B49/083</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B49/081</class-ref>, <class-ref scheme="cpc">E21B49/083</class-ref>, and <class-ref scheme="cpc">E21B49/0815</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B49/082" definition-exists="false" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B49/082</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Wire-line fluid samplers </text><reference><text><class-ref scheme="cpc">E21B49/083</class-ref> takes precedence</text></reference></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B49/083" definition-exists="false" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/083</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Samplers adapted to be lowered into or retrieved from a landing nipple, e.g. for testing a well without removing the drill string</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B49/083</class-ref> is impacted by reclassification into groups <class-ref scheme="cpc">E21B49/0813</class-ref> and <class-ref scheme="cpc">E21B49/0815</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B49/083</class-ref>, <class-ref scheme="cpc">E21B49/0813</class-ref>, and <class-ref scheme="cpc">E21B49/0815</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B49/084" definition-exists="false" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B49/084</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>with means for conveying samples through pipe to surface</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B49/086" definition-exists="false" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B49/086</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Withdrawing samples at the surface</text></CPC-specific-text></title-part></class-title></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B49/087" definition-exists="false" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/087</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>Well testing, e.g. testing for reservoir productivity or formation parameters</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-source">Group <class-ref scheme="cpc">E21B49/087</class-ref> is impacted by reclassification into group <class-ref scheme="cpc">E21B49/0875</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B49/087</class-ref> and <class-ref scheme="cpc">E21B49/0875</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B49/0875" definition-exists="true" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B49/0875</classification-symbol><class-title date-revised="2020-05-01"><title-part><CPC-specific-text><text>determining specific fluid parameters</text></CPC-specific-text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B49/0875</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B49/087</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B49/087</class-ref> and <class-ref scheme="cpc">E21B49/0875</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="10" additional-only="false" sort-key="E21B49/088" definition-exists="false" ipc-concordant="E21B49/08" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B49/088</classification-symbol><class-title date-revised="2013-01-01"><title-part><CPC-specific-text><text>combined with sampling</text></CPC-specific-text></title-part></class-title></classification-item></classification-item>
<classification-item breakdown-code="false" not-allocatable="false" level="9" additional-only="false" sort-key="E21B49/10" definition-exists="false" ipc-concordant="E21B49/10" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2013-01-01" status="published"><classification-symbol>E21B49/10</classification-symbol><class-title date-revised="2013-01-01"><title-part><text>using side-wall fluid samplers or testers</text></title-part></class-title></classification-item></classification-item></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="7" additional-only="true" sort-key="E21B200/00" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/00</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Special features related to earth drilling for obtaining oil, gas or water</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/00</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/00</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/01" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/01</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Sealings characterised by their shape</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/01</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/01</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/02" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/02</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Down-hole chokes or valves for variably regulating fluid flow</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/02</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/02</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/03" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/03</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Valves operated by gear mechanisms, e.g. rack and pinion mechanisms</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/03</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/03</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/04" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/04</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Ball valves</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/04</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/04</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/05" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/05</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Flapper valves</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/05</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/05</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/06" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/06</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Sleeve valves</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/06</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/06</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/08" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/08</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Down-hole devices using materials which decompose under well-bore conditions</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/08</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/08</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/09" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/09</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Detecting, eliminating, preventing liquid slugs in production pipes</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/09</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/09</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/20" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/20</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Computer models or simulations, e.g. for reservoirs under production, drill bits</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/20</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/20</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item>
<classification-item breakdown-code="true" not-allocatable="false" level="8" additional-only="true" sort-key="E21B200/22" definition-exists="false" ipc-concordant="CPCONLY" c-set-base-allowed="false" c-set-subsequent-allowed="true" date-revised="2020-05-01" status="published"><classification-symbol>E21B2200/22</classification-symbol><class-title date-revised="2020-05-01"><title-part><text>Fuzzy logic, artificial intelligence, neural networks or the like</text></title-part></class-title><notes-and-warnings><note type="warning"><note-paragraph warning-type="reclass-destination">Group <class-ref scheme="cpc">E21B2200/22</class-ref> is incomplete pending reclassification of documents from group <class-ref scheme="cpc">E21B33/00</class-ref>.<br/>Groups <class-ref scheme="cpc">E21B33/00</class-ref> and <class-ref scheme="cpc">E21B2200/22</class-ref> should be considered in order to perform a complete search.</note-paragraph></note></notes-and-warnings></classification-item></classification-item></classification-item></classification-item></class-scheme>