1. CPC Sections
  2. CPC Section E
  3. CPC Class E21
  4. CPC Subclass E21B
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Version: 2023.05
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CPC
COOPERATIVE PATENT CLASSIFICATION
​
E21B
EARTH DRILLING, e.g. DEEP DRILLING (mining, quarrying E21C; making shafts, driving galleries or tunnels E21D); OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS [2020-05]
WARNINGS

  • The following IPC groups are not in the CPC scheme. The subject matter for these IPC groups is classified in the following CPC groups:
    E21B7/08 covered by E21B 7/06
    E21B43/22 covered by C09K 8/58
  • 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.
Methods or apparatus for drilling [2013-01]
​​
E21B 1/00
Percussion drilling (drives used in the borehole E21B 4/00) [2020-05]
NOTE

  • When classifying in groups E21B 1/12 - E21B 1/38, a symbol from one of the following main groups of B25D should also be given:
    • B25D 9/00 Portable percussive tools with fluid-pressure drives
    • B25D 11/00 Portable percussive tools with motor drive
    • B25D 16/00 Portable percussive machines with superimposed rotation
    • B25D 17/00 Details of, or accessories for, portable power-driven percussive tools
WARNING

​
E21B 1/02
.
Surface drives for drop hammers {or percussion drilling}, e.g. with a cable [2020-05]
WARNING

​
E21B 1/04
. .
Devices for reversing the movement of the rod or cable at the surface [2020-05]
WARNING

  • Group E21B 1/04 is incomplete pending reclassification of documents from groups E21B 1/02 and E21B 1/12.
    All groups listed in this Warning should be considered in order to perform a complete search.
​
E21B 1/12
.
with a reciprocating impulse member (E21B 1/02, E21B 1/38 take precedence) [2020-05]
WARNING

​
E21B 1/14
. .
driven by a rotating mechanism [2020-05]
WARNING

  • Groups E21B 1/14 - E21B 1/20 are incomplete pending reclassification of documents from groups E21B 1/00 and E21B 1/12.
    All groups listed in this Warning should be considered in order to perform a complete search.
E21B 1/16
. . .
with spring-mounted reciprocating masses, e.g. with air cushion [2020-05]
E21B 1/18
. . . .
with elastic joining of the drive to the push-rod by double buffer springs [2020-05]
E21B 1/20
. . .
formed as centrifugal hammers [2020-05]
​
E21B 1/22
. .
driven by electromagnets [2020-05]
WARNING

  • Group E21B 1/22 is incomplete pending reclassification of documents from groups E21B 1/00 and E21B 1/12.
    All groups listed in this Warning should be considered in order to perform a complete search.
​
E21B 1/24
. .
the impulse member being a piston driven directly by fluid pressure [2020-05]
WARNING

  • Groups E21B 1/24 - E21B 1/34 are incomplete pending reclassification of documents from groups E21B 1/00 and E21B 1/12.
    All groups listed in this Warning should be considered in order to perform a complete search.
E21B 1/26
. . .
by liquid pressure [2020-05]
E21B 1/28
. . . .
working with pulses [2020-05]
E21B 1/30
. . .
by air, steam or gas pressure [2020-05]
E21B 1/32
. . . .
working with pulses [2020-05]
E21B 1/34
. . . . .
the impulse member being a piston of an internal-combustion engine [2020-05]
​
E21B 1/36
.
Tool-carrier piston type, i.e. in which the tool is connected to an impulse member [2020-05]
WARNING

  • Group E21B 1/36 is incomplete pending reclassification of documents from groups E21B 1/00, E21B 1/02 and E21B 1/12.
    All groups listed in this Warning should be considered in order to perform a complete search.
​
E21B 1/38
.
Hammer piston type, i.e. in which the tool bit or anvil is hit by an impulse member [2020-05]
WARNING

  • Group E21B 1/38 is incomplete pending reclassification of documents from groups E21B 1/00, E21B 1/02 and E21B 1/12.
    All groups listed in this Warning should be considered in order to perform a complete search.
​
E21B 3/00
Rotary drilling (drives used in the borehole E21B 4/00; rotary drilling machines in general B23B) [2020-05]
WARNING

​
E21B 3/02
.
Surface drives for rotary drilling [2020-05]
WARNING

​
E21B 3/022
. .
{Top drives} [2020-05]
WARNING

​
E21B 3/025
. .
with a to-and-fro rotation of the tool [2020-05]
WARNING

​
E21B 3/03
. .
with an intermittent unidirectional rotation of the tool [2020-05]
WARNING

​
E21B 3/035
. .
with slipping or elastic transmission [2020-05]
WARNING

​
E21B 3/04
. .
Rotary tables {(portable drilling rigs with rotary tables E21B 7/021)} [2020-05]
WARNING

  • Groups E21B 3/04 – E21B 3/06 are incomplete pending reclassification of documents from group E21B 3/00.
    All groups listed in this Warning should be considered in order to perform a complete search.
E21B 3/045
. . .
{movably mounted on the drilling structure or platform (derricks adapted to be moved on their substructure E21B 15/003)} [2020-05]
E21B 3/06
. . .
Adaptation of rotary draw works to drive rotary tables (connecting or disconnecting couplings or joints E21B 19/16; rope, cable, or chain winding mechanisms, capstans B66D) [2013-01]
E21B 4/00
Drives for drilling, used in the borehole [2020-05]
E21B 4/003
.
{Bearing, sealing, lubricating details (for roller bits E21B 10/22)} [2020-05]
E21B 4/006
.
{Mechanical motion converting means, e.g. reduction gearings (E21B 4/10 takes precedence)} [2020-05]
E21B 4/02
.
Fluid rotary type drives (hydraulic turbines for drilling wells F03B 13/02) [2013-01]
E21B 4/04
.
Electric drives (E21B 4/12 takes precedence) [2013-01]
E21B 4/06
.
Down-hole impacting means, e.g. hammers (percussion drill bits E21B 10/36; boring rams E21B 11/02; releasing-jars E21B 31/107) [2013-01]
E21B 4/08
. .
impact being obtained by gravity only, e.g. with lost-motion connection [2013-01]
E21B 4/10
. .
continuous unidirectional rotary motion of shaft or drilling pipe effecting consecutive impacts [2013-01]
E21B 4/12
. .
Electrically operated hammers [2013-01]
E21B 4/14
. .
Fluid operated hammers [2013-01]
E21B 4/145
. . .
{of the self propelled-type, e.g. with a reverse mode to retract the device from the hole} [2013-01]
E21B 4/16
.
Plural down-hole drives, e.g. for combined percussion and rotary drilling (E21B 4/10 takes precedence); Drives for multi-bit drilling units [2013-01]
E21B 4/18
.
Anchoring or feeding in the borehole [2013-01]
E21B 4/20
.
combined with surface drive (E21B 4/10 takes precedence) [2013-01]
E21B 6/00
Drives for drilling with combined rotary and percussive action (drives used in the borehole E21B 4/00; portable percussive machines with superimposed rotation B25D 16/00) [2020-05]
E21B 6/02
.
the rotation being continuous [2013-01]
E21B 6/04
. .
Separate drives for percussion and rotation [2013-01]
E21B 6/06
.
the rotation being intermittent, e.g. obtained by ratchet device [2017-01]
E21B 6/08
. .
Separate drives for percussion and rotation [2013-01]
E21B 7/00
Special methods or apparatus for drilling [2013-01]
E21B 7/001
.
{Drilling a non circular hole (excavating trenches E02F 5/02; cutting machines for slitting E21C 25/00)} [2013-01]
E21B 7/002
.
{Drilling with diversely driven shafts extending into the borehole (simultaneously drilling and casing E21B 7/20; plural down-hole drives E21B 4/16; E21B 7/001 takes precedence)} [2013-01]
E21B 7/003
.
{Drilling with mechanical conveying means (tunnelling E21D)} [2020-05]
E21B 7/005
. .
{with helical conveying means (E21B 7/201 takes precedence; augers E21B 10/44; drilling rods or pipes with helical structure E21B 17/22)} [2013-01]
E21B 7/006
. . .
{combined with a bucket-type container} [2020-05]
E21B 7/007
.
{Drilling by use of explosives (underwater drilling using explosives E21B 7/1245)} [2020-05]
E21B 7/008
.
{Drilling ice or a formation covered by ice} [2013-01]
E21B 7/02
.
Drilling rigs characterized by means for land transport {with their own drive}, e.g. skid mounting or wheel mounting (portable drilling rigs for use on underwater floors E21B 7/124) [2020-05]
E21B 7/021
. .
{With a rotary table, i.e. a fixed rotary drive for a relatively advancing tool} [2020-05]
E21B 7/022
. .
{Control of the drilling operation; Hydraulic or pneumatic means for activation or operation (control circuits for drilling masts E21B 15/045)} [2013-01]
E21B 7/023
. .
{the mast being foldable or telescopically retractable} [2013-01]
E21B 7/024
. .
{having means for adapting to inclined terrain; having means for stabilizing the vehicle while drilling} [2013-01]
E21B 7/025
. .
{Rock drills, i.e. jumbo drills} [2013-01]
E21B 7/026
. .
{having auxiliary platforms, e.g. for observation purposes} [2013-01]
E21B 7/027
. .
{Drills for drilling shallow holes, e.g. for taking soil samples or for drilling postholes} [2013-01]
​
E21B 7/028
. . .
{the drilling apparatus being detachable from the vehicle, e.g. hand portable drills} [2020-05]
WARNING

E21B 7/04
.
Directional drilling {(derricks or masts specially adapted therefor E21B 15/04)} [2020-05]
E21B 7/043
. .
{for underwater installations} [2013-01]
E21B 7/046
. .
{horizontal drilling (drilling with mechanical conveying means E21B 7/003)} [2013-01]
E21B 7/06
. .
Deflecting the direction of boreholes [2020-05]
E21B 7/061
. . .
{the tool shaft advancing relative to a guide, e.g. a curved tube or a whipstock} [2013-01]
E21B 7/062
. . .
{the tool shaft rotating inside a non-rotating guide travelling with the shaft (E21B 7/067 and E21B 7/068 take precedence)} [2013-01]
E21B 7/064
. . .
{specially adapted drill bits therefor} [2013-01]
E21B 7/065
. . .
{using oriented fluid jets} [2013-01]
E21B 7/067
. . .
{with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub} [2013-01]
E21B 7/068
. . .
{drilled by a down-hole drilling motor (down-hole drives per se E21B 4/00, E21B 7/067 takes precedence)} [2013-01]
E21B 7/10
. .
Correction of deflected boreholes [2013-01]
E21B 7/12
.
Underwater drilling ({derricks or masts specially adapted therefor E21B 15/02;} telescoping joints E21B 17/07; using heave compensators E21B 19/09; well heads specially adapted for underwater installations E21B 33/035) [2020-05]
E21B 7/122
. .
{with submersible vertically movable guide} [2013-01]
E21B 7/124
. .
with underwater tool drive prime mover, e.g. portable drilling rigs for use on underwater floors [2013-01]
E21B 7/1245
. . .
{using explosive means (anchors driven in by explosive charges B63B 21/28)} [2017-08]
E21B 7/128
. .
from floating support with independent underwater anchored guide base [2020-05]
E21B 7/132
. .
from underwater buoyant support [2013-01]
E21B 7/136
. .
from non-buoyant support (E21B 7/124 takes precedence) [2013-01]
E21B 7/14
.
Drilling by use of heat, e.g. flame drilling [2020-05]
E21B 7/143
. .
{underwater} [2013-01]
E21B 7/146
. .
{Thermal lances} [2013-01]
E21B 7/15
. .
of electrically generated heat [2013-01]
E21B 7/16
.
Applying separate balls or pellets by the pressure of the drill, so-called shot-drilling [2013-01]
E21B 7/18
.
Drilling by liquid or gas jets, with or without entrained pellets (E21B 7/14 takes precedence; hydraulic monitors E21C 45/00) [2020-05]
E21B 7/185
. .
{underwater} [2013-01]
E21B 7/20
.
Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes (surface means for applying to-and-fro rotation movements to the casing E21B 3/025; placing piles E02D 7/00; sinking shafts while moving the lining downwards E21D 1/08 {; making galleries by forcing prefabricated elements through the ground E21D 9/005}) [2020-05]
E21B 7/201
. .
{with helical conveying means} [2020-05]
E21B 7/203
. . .
{using down-hole drives} [2020-05]
​
E21B 7/205
. .
{without earth removal (E21B 7/30 takes precedence)} [2013-01]
NOTE

  • Special methods or apparatus for drilling without earth removal E21B 7/26
E21B 7/206
. . .
{using down-hole drives} [2020-05]
E21B 7/208
. .
{using down-hole drives (E21B 7/203 and E21B 7/206 take precedence)} [2020-05]
E21B 7/24
.
Drilling using vibrating or oscillating means, e.g. out-of-balance masses (percussion drilling E21B 1/00) [2013-01]
​
E21B 7/26
.
Drilling without earth removal, e.g. with self-propelled burrowing devices (E21B 7/30 takes precedence; down-hole drives E21B 4/00 {, e.g. self-propelled fluid-operated hammers E21B 4/145}) [2020-05]
WARNING

​
E21B 7/265
. .
{Combined with earth removal} [2020-05]
WARNING

​
E21B 7/267
. .
{Drilling devices with senders, e.g. radio-transmitters for position of drilling tool} [2020-05]
WARNING

E21B 7/28
.
Enlarging drilled holes, e.g. by counterboring (drill bits for enlarging the borehole E21B 10/26) [2013-01]
E21B 7/30
. .
without earth removal [2013-01]
Drilling tools [2013-01]
E21B 10/00
Drill bits (specially adapted for deflecting the direction of boring E21B 7/064; with means for collecting substances E21B 27/00) [2013-01]
E21B 10/003
.
{with cutting edges facing in opposite axial directions} [2013-01]
E21B 10/006
.
{providing a cutting edge which is self-renewable during drilling} [2013-01]
E21B 10/02
.
Core bits (characterised by wear resisting parts E21B 10/46; obtaining undisturbed cores E21B 25/00) [2013-01]
E21B 10/04
. .
with core destroying means [2013-01]
E21B 10/06
. .
Roller core bits [2013-01]
E21B 10/08
.
Roller bits (roller core bits E21B 10/06; with leading portion E21B 10/26; characterised by wear resisting parts E21B 10/46) [2013-01]
E21B 10/083
. .
{with longitudinal axis, e.g. wobbling or nutating roller bit (longitudinal axis roller reamers E21B 10/30)} [2013-01]
E21B 10/086
. .
{with excentric movement} [2013-01]
E21B 10/10
. .
with roller axle supported at both ends (with disc-cutters E21B 10/12) [2013-01]
E21B 10/12
. .
with discs cutters [2013-01]
E21B 10/14
. .
combined with non-rolling cutters other than of leading-portion type [2013-01]
E21B 10/16
. .
characterised by tooth form or arrangement [2013-01]
E21B 10/18
. .
characterised by conduits or nozzles for drilling fluids (drilling fluid supply to the bearings E21B 10/23) [2013-01]
E21B 10/20
. .
characterised by detachable or adjustable parts, e.g. legs or axles (cross axle roller bits E21B 10/10) [2013-01]
E21B 10/22
. .
characterised by bearing, lubrication or sealing details [2013-01]
E21B 10/23
. . .
with drilling fluid supply to the bearings [2013-01]
E21B 10/24
. . .
characterised by lubricating details [2013-01]
E21B 10/246
. . . .
{with pumping means for feeding lubricant} [2013-01]
E21B 10/25
. . .
characterised by sealing details [2013-01]
​
E21B 10/26
.
Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers (percussion drill bits with leading portion E21B 10/40; augers with leading portion E21B 10/44) [2020-05]
WARNING

​
E21B 10/265
. .
{Bi-center drill bits, i.e. an integral bit and eccentric reamer used to simultaneously drill and underream the hole} [2020-05]
WARNING

​
E21B 10/28
. .
with non-expansible roller cutters [2020-05]
WARNING

​
E21B 10/30
. . .
Longitudinal axis roller reamers, e.g. reamer stabilisers [2020-05]
WARNING

​
E21B 10/32
. .
with expansible cutting tools [2020-05]
WARNING

​
E21B 10/322
. . .
{cutter shifted by fluid pressure (E21B 10/345 takes precedence)} [2020-05]
WARNING

​
E21B 10/325
. . .
{the cutter being shifted by a spring mechanism} [2020-05]
WARNING

​
E21B 10/327
. . .
{the cutter being pivoted about a longitudinal axis (E21B 10/34 takes precedence)} [2020-05]
WARNING

​
E21B 10/34
. . .
of roller-cutter type [2020-05]
WARNING

​
E21B 10/345
. . . .
{cutter shifted by fluid pressure} [2020-05]
WARNING

E21B 10/36
.
Percussion drill bits ({with helical conveying portion E21B 10/445;} characterised by wear resisting parts E21B 10/46) [2020-05]
E21B 10/38
. .
characterised by conduits or nozzles for drilling fluids [2013-01]
E21B 10/40
. .
with leading portion [2013-01]
​
E21B 10/42
.
Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits (characterised by wear resisting parts {E21B 10/54}; by conduits or nozzles for drilling fluid E21B 10/60; by detachable or adjustable parts E21B 10/62) [2020-05]
WARNING

​
E21B 10/43
. .
characterised by the arrangement of teeth or other cutting elements [2020-05]
WARNING

E21B 10/44
.
Bits with helical conveying portion, e.g. screw type bits; Augers with leading portion or with detachable parts (E21B 10/42 takes precedence; drilling rods with helical structure E21B 17/22) [2020-05]
E21B 10/445
. .
{percussion type, e.g. for masonry} [2020-05]
E21B 10/46
.
characterised by wear resisting parts, e.g. diamond inserts [2020-05]
E21B 10/48
. .
the bit being of core type [2020-05]
E21B 10/485
. . .
{with inserts in form of chisels, blades or the like} [2013-01]
E21B 10/50
. .
the bit being of roller type [2013-01]
E21B 10/52
. . .
with chisel- or button-type inserts [2020-05]
E21B 10/54
. .
the bit being of the rotary drag type, e.g. fork-type bits [2013-01]
E21B 10/55
. . .
with preformed cutting elements (inserts per se E21B 10/56, E21B 10/58) [2020-05]
E21B 10/56
. .
Button-type inserts (E21B 10/52 takes precedence) [2020-05]
​
E21B 10/567
. . .
with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts [2020-05]
WARNING

​
E21B 10/5671
. . . .
{with chip breaking arrangements} [2020-05]
WARNING

​
E21B 10/5673
. . . .
{having a non planar or non circular cutting face} [2020-05]
WARNING

E21B 10/5676
. . . .
{having a cutting face with different segments, e.g. mosaic-type inserts} [2013-01]
E21B 10/573
. . . .
characterised by support details, e.g. the substrate construction or the interface between the substrate and the cutting element [2020-05]
E21B 10/5735
. . . . .
{Interface between the substrate and the cutting element} [2013-01]
E21B 10/58
. .
Chisel-type inserts ({E21B 10/485,} E21B 10/52, E21B 10/54 take precedence) [2020-05]
E21B 10/60
.
characterised by conduits or nozzles for drilling fluids (for roller bits E21B 10/18; for percussion drill bits E21B 10/38) [2020-05]
E21B 10/602
. .
{the bit being a rotary drag type bit with blades} [2013-01]
E21B 10/605
. .
{the bit being a core-bit} [2013-01]
E21B 10/61
. .
characterised by the nozzle structure [2013-01]
​
E21B 10/62
.
characterised by parts, e.g. cutting elements, which are detachable or adjustable (E21B 10/64 takes precedence; for roller bits E21B 10/20; for augers E21B 10/44) [2020-05]
WARNING

E21B 10/627
. .
with plural detachable cutting elements [2013-01]
E21B 10/633
. . .
independently detachable [2013-01]
E21B 10/64
.
characterised by the whole or part thereof being insertable into or removable from the borehole without withdrawing the drilling pipe (retrievable core receivers E21B 25/02) [2013-01]
E21B 10/66
. .
the cutting element movable through the drilling pipe and laterally shiftable [2013-01]
​
E21B 11/00
Other drilling tools [2020-05]
WARNING

​
E21B 11/005
.
{Hand operated drilling tools (hand portable tools detachable from portable drilling rigs E21B 7/028)} [2020-05]
WARNING

E21B 11/02
.
Boring rams (percussion drives used in the borehole E21B 4/06; percussion drill bits E21B 10/36) [2013-01]
​
E21B 11/04
.
Boring grabs [2020-05]
WARNING

E21B 11/06
.
with driven cutting chains or similarly driven tools [2013-01]
E21B 12/00
Accessories for drilling tools [2020-05]
E21B 12/02
.
Wear indicators [2013-01]
E21B 12/04
.
Drill bit protectors [2013-01]
E21B 12/06
.
Mechanical cleaning devices [2013-01]
Other equipment or details for drilling; Well equipment or well maintenance [2013-01]
E21B 15/00
Supports for the drilling machine, e.g. derricks or masts [2020-05]
E21B 15/003
.
{adapted to be moved on their substructure, e.g. with skidding means; adapted to drill a plurality of wells} [2020-05]
E21B 15/006
.
{Means for anchoring the drilling machine to the ground} [2013-01]
E21B 15/02
.
specially adapted for underwater drilling (E21B 15/04 takes precedence; floating drilling platforms B63B 35/44; drilling platforms on legs E02B 17/00) [2020-05]
E21B 15/04
.
specially adapted for directional drilling, e.g. slant hole rigs [2020-05]
E21B 15/045
. .
{Hydraulic, pneumatic or electric circuits for their positioning} [2013-01]
E21B 17/00
Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; {Cables;} Casings; Tubings (rod couplings in general F16D; tubes or tube couplings in general F16L) [2020-05]
E21B 17/003
.
{with electrically conducting or insulating means (E21B 17/028 and E21B 17/023 take precedence)} [2013-01]
E21B 17/006
.
{Accessories for drilling pipes, e.g. cleaners (wear protectors E21B 17/10; handling drilling pipes E21B 19/00; thread protectors B65D 59/00)} [2013-01]
E21B 17/01
.
Risers ({supporting a riser from a drilling or production platform E21B 19/004;} riser connectors {on well heads} E21B 33/038) [2020-05]
E21B 17/012
. .
{with buoyancy elements (E21B 17/015 takes precedence)} [2013-01]
E21B 17/015
. .
{Non-vertical risers, e.g. articulated or catenary-type} [2013-01]
E21B 17/017
. .
{Bend restrictors for limiting stress on risers} [2013-01]
​
E21B 17/02
.
Couplings; joints {(expandable couplings or joints E21B 43/106)} [2020-05]
WARNING

E21B 17/021
. .
{Devices for subsurface connecting or disconnecting by rotation} [2020-05]
E21B 17/023
. .
{Arrangements for connecting cables or wirelines to downhole devices} [2013-01]
E21B 17/025
. . .
{Side entry subs} [2013-01]
E21B 17/026
. . .
{Arrangements for fixing cables or wirelines to the outside of downhole devices} [2020-05]
​
E21B 17/028
. .
{Electrical or electro-magnetic connections} [2020-05]
WARNING

​
E21B 17/0283
. . .
{characterised by the coupling being contactless, e.g. inductive} [2020-05]
WARNING

​
E21B 17/0285
. . .
{characterised by electrically insulating elements} [2020-05]
WARNING

E21B 17/03
. .
between drilling rod or pipe and drill motor {or surface drive}, e.g. between drilling rod and hammer [2020-05]
​
E21B 17/04
. .
between rod {or the like} and bit or between rod and rod {or the like} [2020-05]
WARNING

​
E21B 17/041
. . .
{specially adapted for coiled tubing} [2020-05]
WARNING

E21B 17/042
. . .
Threaded [2020-05]
E21B 17/0423
. . . .
{with plural threaded sections, e.g. with two-step threads} [2013-01]
E21B 17/0426
. . . .
{with a threaded cylindrical portion, e.g. for percussion rods} [2013-01]
E21B 17/043
. . . .
with locking means [2013-01]
​
E21B 17/046
. . .
with ribs, pins, or jaws, and complementary grooves or the like, e.g. bayonet catches [2020-05]
WARNING

​
E21B 17/0465
. . . .
{characterised by radially inserted locking elements} [2020-05]
WARNING

E21B 17/05
. . .
Swivel joints [2013-01]
E21B 17/06
. . .
Releasing-joints, e.g. safety joints [2013-01]
E21B 17/07
. . .
Telescoping joints for varying drill string lengths; Shock absorbers (heave compensators in the derrick E21B 19/09; releasing-jars E21B 31/107) [2020-05]
E21B 17/073
. . . .
{with axial rotation} [2013-01]
E21B 17/076
. . . .
{between rod or pipe and drill bit} [2013-01]
E21B 17/08
. .
Casing joints [2013-01]
​
E21B 17/085
. . .
{Riser connections (connectors for wellhead E21B 33/038)} [2020-05]
WARNING

​
E21B 17/0853
. . . .
{Connections between sections of riser provided with auxiliary lines, e.g. kill and choke lines} [2020-05]
WARNING

E21B 17/10
.
Wear protectors; Centralising devices {, e.g. stabilisers} (drives used in the borehole with anchoring means E21B 4/18; guiding or centralising devices outside the borehole E21B 19/24) [2020-05]
E21B 17/1007
. .
{for the internal surface of a pipe, e.g. wear bushings for underwater well-heads} [2013-01]
E21B 17/1014
. .
{Flexible or expansible centering means, e.g. with pistons pressing against the wall of the well (E21B 17/1042 takes precedence)} [2013-01]
E21B 17/1021
. . .
{with articulated arms or arcuate springs} [2020-05]
E21B 17/1028
. . . .
{with arcuate springs only, e.g. baskets with outwardly bowed strips for cementing operations} [2013-01]
E21B 17/1035
. .
{for plural rods, pipes or lines, e.g. for control lines} [2013-01]
E21B 17/1042
. .
{Elastomer protector or centering means} [2013-01]
E21B 17/105
. . .
{split type} [2013-01]
E21B 17/1057
. .
{Centralising devices with rollers or with a relatively rotating sleeve (E21B 17/1014 takes precedence)} [2013-01]
E21B 17/1064
. . .
{Pipes or rods with a relatively rotating sleeve} [2013-01]
E21B 17/1071
. .
{specially adapted for pump rods, e.g. sucker rods} [2013-01]
E21B 17/1078
. .
{Stabilisers or centralisers for casing, tubing or drill pipes (devices for off-center positioning E21B 17/10; E21B 17/1007 - E21B 17/1064 take precedence)} [2016-05]
E21B 17/1085
. .
{Wear protectors; Blast joints; Hard facing (wear protection included in centralising devices, see relevant subgroups)} [2013-01]
E21B 17/1092
. .
{Gauge section of drill bits} [2013-01]
E21B 17/12
. .
Devices for placing or drawing out wear protectors [2013-01]
E21B 17/14
.
Casing shoes {for the protection of the bottom of the casing} [2013-01]
E21B 17/16
.
Drill collars [2013-01]
E21B 17/18
.
Pipes provided with plural fluid passages ({E21B 17/203 takes precedence;} circulation of drilling fluid by means of such pipes E21B 21/12) [2020-05]
E21B 17/20
.
Flexible or articulated drilling pipes {, e.g. flexible or articulated rods, pipes or cables} [2020-05]
E21B 17/203
. .
{with plural fluid passages} [2013-01]
E21B 17/206
. .
{with conductors, e.g. electrical, optical} [2020-05]
E21B 17/22
.
Rods or pipes with helical structure (drill bits with helical conveying portion E21B 10/44) [2013-01]
E21B 19/00
Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables (surface drives E21B 1/02, E21B 3/02) [2020-05]
E21B 19/002
.
{specially adapted for underwater drilling (E21B 19/09, E21B 19/143 take precedence)} [2020-05]
E21B 19/004
. .
{supporting a riser from a drilling or production platform} [2013-01]
E21B 19/006
. . .
{including heave compensators} [2013-01]
E21B 19/008
.
{Winding units, specially adapted for drilling operations} [2020-05]
E21B 19/02
.
Rod or cable suspensions (load-engaging elements for hoisting or lowering purposes in general B66C 1/00; crown blocks or pulley blocks B66D; cable guides B66D 1/36) [2017-08]
E21B 19/04
. .
Hooks [2013-01]
E21B 19/06
. .
Elevators, i.e. rod- or tube-gripping devices [2020-05]
E21B 19/07
. . .
Slip-type elevators (slips in rotary tables E21B 19/10) [2020-05]
​
E21B 19/08
.
Apparatus for feeding the rods or cables (E21B 19/22 takes precedence; automatic feed E21B 44/02; hoisting drums B66D); Apparatus for increasing or decreasing the pressure on the drilling tool; Apparatus for counterbalancing the weight of the rods [2020-05]
WARNING

​
E21B 19/081
. .
Screw-and-nut feed mechanisms [2020-05]
WARNING

​
E21B 19/083
. .
Cam, rack or like feed mechanisms [2020-05]
WARNING

​
E21B 19/084
. .
with flexible drawing means, e.g. cables [2020-05]
WARNING

​
E21B 19/086
. .
with a fluid-actuated cylinder (E21B 19/084, E21B 19/087, E21B 19/09 take precedence) [2020-05]
WARNING

​
E21B 19/087
. .
by means of a swinging arm [2020-05]
WARNING

​
E21B 19/089
. .
with a spring or an additional weight [2020-05]
WARNING

​
E21B 19/09
. .
specially adapted for drilling underwater formations from a floating support using heave compensators supporting the drill string (drilling-pipe telescoping joints E21B 17/07 {; heave compensators for supporting a riser E21B 19/006}) [2020-05]
WARNING

​
E21B 19/10
.
Slips; Spiders {; Catching devices (rotary tables with master bushing or kelly bushing E21B 3/04)} [2020-05]
WARNING

​
E21B 19/102
. .
{using rollers or spherical balls as load gripping elements} [2020-05]
WARNING

E21B 19/12
.
Rope clamps {; Rod, casings or tube clamps not secured to elevators} (rope clamps in general F16G 11/00) [2020-05]
E21B 19/14
.
Racks, ramps, troughs or bins, for holding the lengths of rod singly or connected; Handling between storage place and borehole (E21B 19/20, E21B 19/22 take precedence) [2020-05]
E21B 19/143
. .
{specially adapted for underwater drilling} [2013-01]
E21B 19/146
. .
{Carousel systems, i.e. rotating rack systems} [2013-01]
E21B 19/15
. .
Racking of rods in horizontal position; Handling between horizontal and vertical position [2013-01]
E21B 19/155
. . .
{Handling between horizontal and vertical position} [2013-01]
E21B 19/16
.
Connecting or disconnecting pipe couplings or joints (E21B 19/20 takes precedence; pipe wrenches or the like B25B) [2017-08]
E21B 19/161
. .
{using a wrench or a spinner adapted to engage a circular section of pipe (E21B 19/168 takes precedence)} [2013-01]
E21B 19/162
. . .
{cathead actuated} [2013-01]
E21B 19/163
. . .
{piston-cylinder actuated} [2013-01]
E21B 19/164
. . .
{motor actuated (E21B 19/162 and E21B 19/163 take precedence)} [2013-01]
E21B 19/165
. .
{Control or monitoring arrangements therefor} [2013-01]
E21B 19/166
. . .
{Arrangements of torque limiters or torque indicators} [2013-01]
E21B 19/167
. .
{using a wrench adapted to engage a non circular section of pipe, e.g. a section with flats or splines} [2013-01]
E21B 19/168
. .
{using a spinner with rollers or a belt adapted to engage a well pipe} [2013-01]
E21B 19/18
.
Connecting or disconnecting drill bit and drilling pipe [2013-01]
E21B 19/20
.
Combined feeding from rack and connecting, e.g. automatically [2013-01]
E21B 19/22
.
Handling reeled pipe or rod units, e.g. flexible drilling pipes {(lifting or hauling appliances using two or more cooperating endless chains B66D 3/003)} [2013-01]
E21B 19/24
.
Guiding or centralising devices for drilling rods or pipes [2013-01]
​
E21B 21/00
Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor (freeing objects stuck in boreholes by flushing E21B 31/03; well drilling compositions C09K 8/02) [2020-05]
WARNING

​
E21B 21/001
.
{specially adapted for underwater drilling (dual gradient drilling E21B 21/082)} [2020-05]
WARNING

​
E21B 21/002
.
{Down-hole drilling fluid separation systems (containers comprising collecting means with a strainer E21B 27/005; subsoil filtering E21B 43/02; down-hole production separators E21B 43/38)} [2020-05]
WARNING

​
E21B 21/003
.
{Means for stopping loss of drilling fluid (plastering the borehole wall E21B 33/138)} [2020-05]
WARNING

​
E21B 21/01
.
Arrangements for handling drilling fluids or cuttings outside the borehole, e.g. mud boxes (arrangements for treating drilling fluids E21B 21/06 {; waste disposal systems E21B 41/005}) [2020-05]
WARNING

E21B 21/011
. .
{Dust eliminating or dust removing while drilling} [2020-05]
​
E21B 21/012
. . .
{using exhaust air from the drilling motor for blowing off the dust at the borehole entrance} [2020-05]
WARNING

E21B 21/013
. . .
{by liquids} [2020-05]
E21B 21/0135
. . . .
{Liquid flushing installations} [2020-05]
E21B 21/014
. . .
{Preventing exhaust air from the drill motor from blowing-off towards the working face} [2020-05]
​
E21B 21/015
. .
Means engaging the bore entrance, e.g. hoods for collecting dust [2020-05]
WARNING

​
E21B 21/019
. .
{Arrangements for maintaining circulation of drilling fluid while connecting or disconnecting tubular joints} [2020-05]
WARNING

​
E21B 21/02
.
Swivel joints in hose-lines [2020-05]
WARNING

​
E21B 21/06
.
Arrangements for treating drilling fluids outside the borehole (treating steps per se, see the relevant subclasses) [2020-05]
WARNING

  • Groups E21B 21/06 - E21B 21/07 are incomplete pending reclassification of documents from group E21B 21/00.
    All groups listed in this Warning should be considered in order to perform a complete search.
E21B 21/062
. .
{by mixing components} [2013-01]
E21B 21/063
. .
{by separating components} [2013-01]
E21B 21/065
. . .
{Separating solids from drilling fluids} [2013-01]
E21B 21/066
. . . .
{with further treatment of the solids, e.g. for disposal} [2013-01]
E21B 21/067
. . .
{Separating gases from drilling fluids} [2013-01]
E21B 21/068
. .
{using chemical treatment} [2013-01]
E21B 21/07
. .
for treating dust-laden gaseous fluids [2013-01]
​
E21B 21/08
.
Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure (valve arrangements therefor E21B 21/10) [2020-05]
WARNING

​
E21B 21/082
. .
{Dual gradient systems, i.e. using two hydrostatic gradients or drilling fluid densities} [2020-05]
WARNING

​
E21B 21/085
. .
{Underbalanced techniques, i.e. where borehole fluid pressure is below formation pressure} [2020-05]
WARNING

​
E21B 21/10
.
Valve arrangements in drilling-fluid circulation systems (valves in general F16K) [2020-05]
WARNING

  • Groups E21B 21/10 - E21B 21/106 are incomplete pending reclassification of documents from group E21B 21/00.
    All groups listed in this Warning should be considered in order to perform a complete search.
E21B 21/103
. .
{Down-hole by-pass valve arrangements, i.e. between the inside of the drill string and the annulus} [2013-01]
E21B 21/106
. .
{Valve arrangements outside the borehole, e.g. kelly valves} [2013-01]
​
E21B 21/12
.
using drilling pipes with plural fluid passages, e.g. closed circulation systems (pipes with plural fluid passages E21B 17/18) [2020-05]
WARNING

​
E21B 21/14
.
using liquids and gases, e.g. foams [2020-05]
WARNING

​
E21B 21/16
.
using gaseous fluids (E21B 21/14 takes precedence; arrangements for handling drilling fluids outside the borehole E21B 21/01; arrangements for treating drilling fluids E21B 21/06) [2020-05]
WARNING

​
E21B 21/18
.
Preventing exhaust air from the drill motor from blowing-off towards the working face [2020-05]
WARNING

E21B 23/00
Apparatus for displacing, setting, locking, releasing, or removing tools, packers or the like in the boreholes or wells (setting of casings, screens or liners E21B 43/10) [2013-01]
E21B 23/001
.
{Self-propelling systems or apparatus, e.g. for moving tools within the horizontal portion of a borehole} [2020-05]
E21B 23/004
.
{Indexing systems for guiding relative movement between telescoping parts of downhole tools} [2013-01]
E21B 23/006
. .
{"J-slot" systems, i.e. lug and slot indexing mechanisms} [2013-01]
E21B 23/01
.
for anchoring the tools or the like (E21B 23/02 - E21B 23/06 take precedence; anchoring of drives in the borehole E21B 4/18) [2020-05]
E21B 23/02
.
for locking the tools or the like in landing nipples or in recesses between adjacent sections of tubing (E21B 23/03 - E21B 23/06 take precedence) [2016-05]
​
E21B 23/03
.
for setting the tools into, or removing the tools from, laterally offset landing nipples or pockets [2020-05]
WARNING

​
E21B 23/04
.
operated by fluid means, e.g. actuated by explosion (E21B 23/06, E21B 23/08 take precedence) [2020-05]
WARNING

​
E21B 23/0411
. .
{specially adapted for anchoring tools or the like to the borehole wall or to well tube} [2020-05]
WARNING

​
E21B 23/04115
. . .
{using radial pistons} [2020-05]
WARNING

​
E21B 23/0412
. .
{characterised by pressure chambers, e.g. vacuum chambers} [2020-05]
WARNING

​
E21B 23/0413
. .
{using means for blocking fluid flow, e.g. drop balls or darts (using balls or the like for actuating downhole valves E21B 34/142)} [2020-05]
WARNING

​
E21B 23/0414
. .
{using explosives} [2020-05]
WARNING

​
E21B 23/0415
. .
{using particular fluids, e.g. electro-active liquids} [2020-05]
WARNING

​
E21B 23/0416
. .
{characterised by force amplification arrangements} [2020-05]
WARNING

​
E21B 23/0417
. .
{Down-hole non-explosive gas generating means, e.g. by chemical reaction} [2020-05]
WARNING

​
E21B 23/0418
. .
{specially adapted for locking the tools in landing nipples or recesses} [2020-05]
WARNING

​
E21B 23/0419
. .
{using down-hole motor and pump arrangements for generating hydraulic pressure} [2020-05]
WARNING

​
E21B 23/042
. .
{using a single piston or multiple mechanically interconnected pistons} [2020-05]
WARNING

​
E21B 23/0421
. .
{using multiple hydraulically interconnected pistons} [2020-05]
WARNING

​
E21B 23/0422
. .
{characterised by radial pistons (using radial pistons for anchoring E21B 23/04115)} [2020-05]
WARNING

​
E21B 23/0423
. .
{using step motors} [2020-05]
WARNING

E21B 23/06
.
for setting packers [2013-01]
E21B 23/065
. .
{setting tool actuated by explosion or gas generating means} [2013-01]
E21B 23/08
.
Introducing or running tools by fluid pressure, e.g. through-the-flow-line tool systems (special provisions on heads therefor E21B 33/068; cementing plugs E21B 33/16; scrapers operated by fluid pressure E21B 37/04) [2020-05]
E21B 23/10
. .
Tools specially adapted therefor [2013-01]
​
E21B 23/12
. .
Tool diverters [2020-05]
WARNING

E21B 23/14
.
for displacing a cable or cable-operated tool, e.g. for logging or perforating operations in deviated wells (by fluid pressure E21B 23/08; provision on well heads for introducing or removing cable-operated tools E21B 33/072, E21B 33/076) [2020-05]
E21B 25/00
Apparatus for obtaining or removing undisturbed cores, e.g. core barrels, core extractors (core bits E21B 10/02; using explosives or projectiles in boreholes E21B 49/04; side-wall sampling or coring E21B 49/06) [2013-01]
E21B 25/005
.
{Above ground means for handling the core, e.g. for extracting the core from the core barrel} [2013-01]
E21B 25/02
.
the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe (retrievable drill bits E21B 10/64) [2013-01]
E21B 25/04
. .
the core receiver having a core forming cutting edge or element, e.g. punch type core barrels [2017-01]
E21B 25/06
.
the core receiver having a flexible liner or inflatable retaining means [2013-01]
E21B 25/08
.
Coating, freezing, consolidating cores (E21B 25/06 takes precedence); Recovering uncontaminated cores or cores at formation pressure [2013-01]
E21B 25/10
.
Formed core retaining or severing means (E21B 25/06, E21B 25/08 take precedence) [2013-01]
E21B 25/12
. .
of the sliding wedge type [2013-01]
E21B 25/14
. .
mounted on pivot transverse to core axis [2013-01]
E21B 25/16
.
for obtaining oriented cores [2013-01]
E21B 25/18
.
the core receiver being specially adapted for operation under water [2013-01]
​
E21B 27/00
Containers for collecting or depositing substances in boreholes or wells, e.g. bailers, {baskets or buckets} for collecting mud or sand; Drill bits with means for collecting substances, e.g. valve drill bits [2020-05]
WARNING

E21B 27/005
.
{Collecting means with a strainer} [2013-01]
E21B 27/02
.
Dump bailers, i.e. containers for depositing substances, e.g. cement or acids [2013-01]
E21B 27/04
.
where the collecting or depositing means include helical conveying means {(drilling with helical conveying means combined with bucket-type container E21B 7/006)} [2020-05]
E21B 28/00
Vibration generating arrangements for boreholes or wells, e.g. for stimulating production (for drilling E21B 7/24; {for fishing for or freeing objects E21B 31/005;} for transmitting measuring-signals E21B 47/14; for geophysical measurements G01V 1/02) [2020-08]
E21B 29/00
Cutting or destroying pipes, packers, plugs, or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows (perforators E21B 43/11); Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground {(by enlarging drilled holes or counterboring E21B 7/28)} [2013-01]
E21B 29/002
.
{Cutting, e.g. milling, a pipe with a cutter rotating along the circumference of the pipe} [2013-01]
E21B 29/005
. .
{with a radially-expansible cutter rotating inside the pipe, e.g. for cutting an annular window} [2013-01]
E21B 29/007
. .
{with a radially-retracting cutter rotating outside the pipe} [2013-01]
E21B 29/02
.
by explosives or by thermal or chemical means ({freeing stuck objects by explosives E21B 31/002;} destroying objects in boreholes or wells by explosives E21B 31/16) [2020-05]
E21B 29/04
.
Cutting of wire lines or the like (E21B 29/02 takes precedence) [2013-01]
E21B 29/06
.
Cutting windows, e.g. directional window cutters for whipstock operations ({E21B 29/005 and} E21B 29/08 take precedence) [2020-05]
E21B 29/08
.
Cutting or deforming pipes to control fluid flow {(shear type blow-out preventers E21B 33/063)} [2020-05]
E21B 29/10
.
Reconditioning of well casings, e.g. straightening [2013-01]
E21B 29/12
.
specially adapted for underwater installations (E21B 29/08 takes precedence) [2013-01]
​
E21B 31/00
Fishing for or freeing objects in boreholes or wells (provisions on well heads for introducing or removing objects E21B 33/068; locating or determining the position of objects in boreholes or wells E21B 47/09) [2020-05]
WARNING

E21B 31/002
.
{Destroying the objects to be fished, e.g. by explosive means} [2020-05]
E21B 31/005
.
{using vibrating or oscillating means} [2020-05]
E21B 31/007
.
{fishing tools with means for attaching comprising fusing or sticking} [2013-01]
​
E21B 31/03
.
Freeing by flushing [2020-05]
WARNING

​
E21B 31/035
.
{controlling differential pipe sticking} [2020-05]
WARNING

E21B 31/06
.
using magnetic means [2013-01]
​
E21B 31/08
.
using junk baskets or the like [2020-05]
WARNING

E21B 31/107
.
using impact means for releasing stuck parts, e.g. jars (telescoping joints E21B 17/07) [2013-01]
E21B 31/1075
. .
{using explosives} [2013-01]
E21B 31/113
. .
hydraulically-operated [2013-01]
E21B 31/1135
. . .
{Jars with a hydraulic impedance mechanism, i.e. a restriction, for initially delaying escape of a restraining fluid} [2017-05]
E21B 31/12
.
Grappling tools, e.g. tongs or grabs [2013-01]
E21B 31/125
. .
{specially adapted for parted wire line or ropes} [2013-01]
E21B 31/14
. .
with means deflecting the direction of the tool, e.g. by use of knuckle joints (apparatus for deflecting the boring {E21B 7/06}) [2020-05]
E21B 31/16
. .
combined with cutting or destroying means (cutting or destroying means per se E21B 29/00) [2013-01]
E21B 31/18
. .
gripping externally, e.g. overshot [2013-01]
E21B 31/20
. .
gripping internally, e.g. fishing spears [2013-01]
​
E21B 33/00
Sealing or packing boreholes or wells [2020-05]
WARNING

E21B 33/02
.
Surface sealing or packing [2013-01]
E21B 33/03
. .
Well heads; Setting-up thereof (valve arrangements therefor E21B 34/02) [2013-01]
​
E21B 33/035
. . .
specially adapted for underwater installations (E21B 33/043, E21B 33/064, E21B 33/076 take precedence) [2020-05]
WARNING

​
E21B 33/0353
. . . .
{Horizontal or spool trees, i.e. without production valves in the vertical main bore} [2020-05]
WARNING

​
E21B 33/0355
. . . .
{Control systems, e.g. hydraulic, pneumatic, electric, acoustic, for submerged well heads} [2020-05]
WARNING

​
E21B 33/037
. . . .
Protective housings therefor [2020-05]
WARNING

​
E21B 33/0375
. . . . .
{Corrosion protection means} [2020-05]
WARNING

​
E21B 33/038
. . . .
Connectors used on well heads, e.g. for connecting blow-out preventer and riser (connecting a production flow-line to an underwater well head E21B 43/013) [2020-05]
WARNING

​
E21B 33/0385
. . . . .
{electrical connectors} [2020-05]
WARNING

​
E21B 33/0387
. . . .
{Hydraulic stab connectors} [2020-05]
WARNING

E21B 33/04
. . .
Casing heads; Suspending casings or tubings in well heads (setting of casings in wells E21B 43/10) [2013-01]
E21B 33/0407
. . . .
{with a suspended electrical cable} [2013-01]
E21B 33/0415
. . . .
{rotating or floating support for tubing or casing hanger} [2013-01]
​
E21B 33/0422
. . . .
{a suspended tubing or casing being gripped by a slip or an internally serrated member} [2020-05]
WARNING

E21B 33/043
. . . .
specially adapted for underwater well heads ({E21B 33/0407,} E21B 33/047 take precedence) [2013-01]
E21B 33/047
. . . .
for plural tubing strings [2013-01]
E21B 33/05
. . . .
Cementing-heads, e.g. having provision for introducing cementing plugs [2013-01]
E21B 33/06
. . .
Blow-out preventers {, i.e. apparatus closing around a drill pipe, e.g. annular blow-out preventers (rotating blow-out preventers E21B 33/085)} [2020-05]
E21B 33/061
. . . .
{Ram-type blow-out preventers, e.g. with pivoting rams} [2013-01]
E21B 33/062
. . . . .
{with sliding rams} [2013-01]
E21B 33/063
. . . . . .
{for shearing drill pipes (cutting of wireline E21B 29/04)} [2020-05]
E21B 33/064
. . . .
specially adapted for underwater well heads ({control systems for submerged well-heads E21B 33/0355;} connectors therefor E21B 33/038) [2020-05]
E21B 33/068
. . .
having provision for introducing objects or fluids into, or removing objects from, wells (cementing heads E21B 33/05 {; wipers, oil savers E21B 33/08}) [2020-05]
E21B 33/072
. . . .
for cable-operated tools (E21B 33/076 takes precedence) [2013-01]
E21B 33/076
. . . .
specially adapted for underwater installations [2013-01]
E21B 33/08
. .
Wipers; Oil savers [2013-01]
E21B 33/085
. . .
{Rotatable packing means, e.g. rotating blow-out preventers} [2013-01]
E21B 33/10
.
in the borehole {(sealing the junction between main bore and laterals E21B 41/0042)} [2013-01]
E21B 33/12
. .
Packers; Plugs (used for cementing E21B 33/134, E21B 33/16) [2020-05]
E21B 33/1204
. . .
{permanent; drillable} [2013-01]
E21B 33/1208
. . .
{characterised by the construction of the sealing or packing means (E21B 33/1277 takes precedence)} [2013-01]
E21B 33/1212
. . . .
{including a metal-to-metal seal element} [2013-01]
E21B 33/1216
. . . .
{Anti-extrusion means, e.g. means to prevent cold flow of rubber packing} [2013-01]
E21B 33/122
. . .
Multiple string packers [2013-01]
E21B 33/124
. . .
Units with longitudinally-spaced plugs for isolating the intermediate space [2013-01]
E21B 33/1243
. . . .
{with inflatable sleeves} [2013-01]
E21B 33/1246
. . . . .
{inflated by down-hole pumping means operated by a pipe string} [2013-01]
E21B 33/126
. . .
with fluid-pressure-operated elastic cup or skirt (E21B 33/122, E21B 33/124 take precedence) [2013-01]
E21B 33/1265
. . . .
{with mechanical slips} [2013-01]
E21B 33/127
. . .
with inflatable sleeve (E21B 33/122, E21B 33/124 take precedence) [2013-01]
E21B 33/1272
. . . .
{inflated by down-hole pumping means operated by a pipe string} [2013-01]
E21B 33/1275
. . . .
{inflated by down-hole pumping means operated by a down-hole drive} [2013-01]
E21B 33/1277
. . . .
{characterised by the construction or fixation of the sleeve} [2013-01]
E21B 33/128
. . .
with a member expanded radially by axial pressure (E21B 33/122, E21B 33/124 {, E21B 33/129} take precedence {; characterised by the construction of the sealing means E21B 33/1208}) [2020-05]
E21B 33/1285
. . . .
{by fluid pressure} [2013-01]
E21B 33/129
. . .
with mechanical slips for hooking into the casing (E21B 33/122, E21B 33/124 take precedence) [2013-01]
E21B 33/1291
. . . .
{anchor set by wedge or cam in combination with frictional effect, using so-called drag-blocks (E21B 33/1295 takes precedence)} [2013-01]
E21B 33/1292
. . . . .
{with means for anchoring against downward and upward movement} [2013-01]
E21B 33/1293
. . . .
{with means for anchoring against downward and upward movement (E21B 33/1291, E21B 33/1295 take precedence)} [2013-01]
E21B 33/1294
. . . .
{characterised by a valve, e.g. a by-pass valve} [2013-01]
E21B 33/1295
. . . .
actuated by fluid pressure [2013-01]
E21B 33/12955
. . . . .
{using drag blocks frictionally engaging the inner wall of the well} [2013-01]
E21B 33/13
. .
Methods or devices for cementing, for plugging holes, crevices, or the like (dump bailers E21B 27/02; chemical compositions therefor C09K 8/00) [2020-05]
E21B 33/134
. . .
Bridging plugs [2020-05]
E21B 33/136
. . .
Baskets, e.g. of umbrella type [2013-01]
E21B 33/138
. . .
Plastering the borehole wall; Injecting into the formation {(packers E21B 33/12)} [2020-05]
E21B 33/14
. . .
for cementing casings into boreholes {(control of cementation quality or level E21B 47/005)} [2020-05]
E21B 33/143
. . . .
{for underwater installations} [2013-01]
E21B 33/146
. . . .
{Stage cementing, i.e. discharging cement from casing at different levels} [2013-01]
​
E21B 33/16
. . . .
using plugs for isolating cement charge; Plugs therefor {(stage cementing E21B 33/146; spacer compositions C09K 8/424)} [2020-05]
WARNING

​
E21B 33/165
. . . . .
{Cementing plugs specially adapted for being released down-hole (cementing heads E21B 33/05)} [2020-05]
WARNING

​
E21B 33/167
. . . . .
{Cementing plugs provided with anti-rotation mechanisms, e.g. for easier drill-out} [2020-05]
WARNING

E21B 34/00
Valve arrangements for boreholes or wells (in drilling fluid circulation systems E21B 21/10; blow-out preventers E21B 33/06; oil flow regulating apparatus E21B 43/12; valves in general F16K) [2020-05]
​
E21B 34/02
.
in well heads [2020-05]
WARNING

​
E21B 34/025
. .
{Chokes or valves in wellheads and sub-sea wellheads for variably regulating fluid flow} [2020-05]
WARNING

​
E21B 34/04
. .
in underwater well heads [2020-05]
WARNING

​
E21B 34/045
. . .
{adapted to be lowered on a tubular string into position within a blow-out preventer stack, e.g. so-called test trees} [2020-05]
WARNING

E21B 34/06
.
in wells [2013-01]
E21B 34/063
. .
{Valve or closure with destructible element, e.g. frangible disc (E21B 34/103 takes precedence)} [2013-01]
E21B 34/066
. .
{electrically actuated} [2013-01]
E21B 34/08
. .
responsive to flow or pressure of the fluid obtained (E21B 34/10 takes precedence) [2013-01]
E21B 34/085
. . .
{with time-delay systems, e.g. hydraulic impedance mechanisms} [2013-01]
E21B 34/10
. .
operated by control fluid supplied from outside the borehole ({by a dropped ball or piston E21B 34/142;} control means being outside the borehole E21B 34/16) [2020-05]
E21B 34/101
. . .
{with means for equalizing fluid pressure above and below the valve} [2013-01]
E21B 34/102
. . .
{with means for locking the closing element in open or closed position (E21B 34/105 and E21B 34/108 take precedence)} [2017-05]
E21B 34/103
. . . .
{with a shear pin} [2013-01]
E21B 34/105
. . .
{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} [2013-01]
E21B 34/106
. . . .
{the retrievable element being a secondary control fluid actuated valve landed into the bore of a first inoperative control fluid actuated valve} [2013-01]
E21B 34/107
. . . .
{the retrievable element being an operating or controlling means retrievable separately from the closure member, e.g. pilot valve landed into a side pocket (E21B 34/106 takes precedence)} [2013-01]
E21B 34/108
. . .
{with time delay systems, e.g. hydraulic impedance mechanisms} [2013-01]
E21B 34/12
. .
operated by movement of casings or tubings [2013-01]
E21B 34/125
. . .
{with time delay systems, e.g. hydraulic impedance mechanisms} [2013-01]
​
E21B 34/14
. .
operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools {(E21B 34/066 takes precedence)} [2020-05]
WARNING

​
E21B 34/142
. . .
{unsupported or free-falling elements, e.g. balls, plugs, darts or pistons} [2020-05]
WARNING

E21B 34/16
.
Control means therefor being outside the borehole {(control systems for submerged well heads E21B 33/0355)} [2020-05]
E21B 35/00
Methods or apparatus for preventing or extinguishing fires (cutting or deforming pipes to control fluid flow E21B 29/08; controlling flow of fluid to or in wells E21B 43/12; fire fighting in general A62C, A62D) [2013-01]
E21B 36/00
Heating, cooling, insulating arrangements for boreholes or wells, e.g. for use in permafrost zones (drilling by use of heat E21B 7/14; secondary recovery methods using heat E21B 43/24) [2013-01]
E21B 36/001
.
{Cooling arrangements} [2013-01]
E21B 36/003
.
{Insulating arrangements} [2013-01]
E21B 36/005
.
{Heater surrounding production tube} [2013-01]
E21B 36/006
.
{Combined heating and pumping means} [2013-01]
E21B 36/008
.
{using chemical heat generating means} [2013-01]
E21B 36/02
.
using burners [2013-01]
E21B 36/025
. .
{the burners being above ground or outside the bore hole} [2013-01]
E21B 36/04
.
using electrical heaters [2013-01]
E21B 37/00
Methods or apparatus for cleaning boreholes or wells (E21B 21/00 takes precedence; {bailers E21B 27/00;} cleaning pipes in general B08B 9/02) [2013-01]
E21B 37/02
.
Scrapers specially adapted therefor [2013-01]
E21B 37/04
. .
operated by fluid pressure, e.g. free-piston scrapers (operating other tools by fluid pressure E21B 23/08) [2013-01]
E21B 37/045
. . .
{Free-piston scrapers} [2013-01]
E21B 37/06
.
using chemical means for preventing, limiting {or eliminating} the deposition of paraffins or like substances (chemical compositions therefor C09K 8/52) [2013-01]
E21B 37/08
.
cleaning in situ of down-hole filters, screens, {e.g. casing perforations,} or gravel packs (E21B 37/06 takes precedence) [2013-01]
E21B 37/10
.
Well swabs [2020-05]
​
E21B 40/00
Tubing catchers, automatically arresting the fall of oil-well tubing {(preventing small objects from falling into the borehole E21B 41/0021)} [2020-05]
WARNING

​
E21B 40/001
.
{in the borehole (anchoring tools in the borehole E21B 23/01)} [2020-05]
WARNING

​
E21B 41/00
Equipment or details not covered by groups E21B 15/00 - E21B 40/00 [2020-05]
WARNING

E21B 41/0007
.
{for underwater installations (E21B 41/005, E21B 41/04, E21B 41/06, E21B 41/08, E21B 41/10 take precedence)} [2013-01]
E21B 41/0014
. .
{Underwater well locating or reentry systems} [2013-01]
E21B 41/0021
.
{Safety devices, e.g. for preventing small objects from falling into the borehole} [2013-01]
E21B 41/0035
.
{Apparatus or methods for multilateral well technology, e.g. for the completion of or workover on wells with one or more lateral branches} [2020-05]
E21B 41/0042
. .
{characterised by sealing the junction between a lateral and a main bore} [2013-01]
E21B 41/005
.
{Waste disposal systems} [2020-05]
E21B 41/0057
. .
{Disposal of a fluid by injection into a subterranean formation} [2013-01]
E21B 41/0064
. . .
{Carbon dioxide sequestration (storing fluids in porous layers B65G 5/005)} [2013-01]
E21B 41/0071
. .
{Adaptation of flares, e.g. arrangements of flares in offshore installations (flares of waste gases or noxious gases F23G 7/08)} [2013-01]
E21B 41/0078
.
{Nozzles used in boreholes (drilling by liquid or gas jets E21B 7/18; drill bits with nozzles E21B 10/60; perforators using direct fluid action E21B 43/114; obtaining a slurry of minerals using nozzles E21B 43/29)} [2020-05]
E21B 41/0085
.
{Adaptations of electric power generating means for use in boreholes} [2020-05]
​
E21B 41/0092
(Frozen)
.
{Methods relating to program engineering, design or optimisation} [2020-05]
WARNING

  • Group E21B 41/0092 is no longer used for the classification of documents as of May 1, 2020.
    The content of this group is being reclassified into groups E21B 41/00, E21B 43/00, E21B 43/16, and G06Q 10/06.
    All groups listed in this Warning should be considered in order to perform a complete search.
​
E21B 41/0099
.
{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} [2020-05]
WARNING

E21B 41/02
.
in situ inhibition of corrosion in boreholes or wells (dump bailers E21B 27/02; chemical compositions therefor C09K 8/54; inhibiting corrosion in general C23F) [2013-01]
E21B 41/04
.
Manipulators for underwater operations, e.g. temporarily connected to well heads (manipulators in general B25J) [2013-01]
E21B 41/06
.
Work chambers for underwater operations, e.g. temporarily connected to well heads (in general B63C 11/00) [2013-01]
E21B 41/08
.
Underwater guide bases, e.g. drilling templates; Levelling thereof [2020-08]
E21B 41/10
.
Guide posts, e.g. releasable; Attaching guide lines to underwater guide bases [2013-01]
Obtaining fluids from wells [2013-01]
​
E21B 43/00
Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B; obtaining oil-bearing deposits or soluble or meltable materials by mining techniques E21C 41/00; pumps F04) [2020-05]
WARNING

E21B 43/003
.
{Vibrating earth formations} [2020-05]
E21B 43/006
.
{Production of coal-bed methane (E21B 43/243 takes precedence)} [2020-05]
E21B 43/01
.
specially adapted for obtaining from underwater installations (underwater well heads E21B 33/035) [2013-01]
E21B 43/0107
. .
{Connecting of flow lines to offshore structures (E21B 43/013 takes precedence)} [2013-01]
E21B 43/0122
. .
{Collecting oil or the like from a submerged leakage (cleaning or keeping clear the surface of open water from oil or the like E02B 15/04)} [2013-01]
E21B 43/013
. .
Connecting a production flow line to an underwater well head [2017-08]
E21B 43/0135
. . .
{using a pulling cable} [2013-01]
​
E21B 43/017
. .
Production satellite stations, i.e. underwater installations comprising a plurality of satellite well heads connected to a central station (underwater separating arrangements E21B 43/36) [2020-05]
WARNING

​
E21B 43/0175
. . .
{Hydraulic schemes for production manifolds} [2020-05]
WARNING

E21B 43/02
.
Subsoil filtering (E21B 43/11 takes precedence; chemical compositions for consolidating loose sand or the like around wells C09K 8/56) [2020-05]
E21B 43/025
. .
{Consolidation of loose sand or the like round the wells without excessively decreasing the permeability thereof} [2020-05]
E21B 43/04
. .
Gravelling of wells [2013-01]
E21B 43/045
. . .
{Crossover tools} [2013-01]
E21B 43/08
. .
Screens or liners {(expandable screens or liners E21B 43/108)} [2020-05]
E21B 43/082
. . .
{Screens comprising porous materials, e.g. prepacked screens} [2013-01]
E21B 43/084
. . .
{Screens comprising woven materials, e.g. mesh or cloth} [2013-01]
E21B 43/086
. . .
{Screens with preformed openings, e.g. slotted liners (comprising porous materials E21B 43/082)} [2013-01]
E21B 43/088
. . .
{Wire screens (comprising porous materials E21B 43/082; comprising woven materials E21B 43/084)} [2013-01]
E21B 43/10
. .
Setting of casings, screens, liners {or the like} in wells (driving or forcing casings into boreholes, simultaneously drilling and casing boreholes E21B 7/20; setting of tools, packers or the like E21B 23/00; suspending casings in well heads E21B 33/04) [2013-01]
E21B 43/101
. . .
{for underwater installations} [2013-01]
E21B 43/103
. . .
{of expandable casings, screens, liners, or the like} [2013-01]
E21B 43/105
. . . .
{Expanding tools specially adapted therefor} [2013-01]
E21B 43/106
. . . .
{Couplings or joints therefor} [2013-01]
E21B 43/108
. . . .
{Expandable screens or perforated liners} [2020-05]
E21B 43/11
.
Perforators; Permeators [2013-01]
E21B 43/112
. .
Perforators with extendable perforating members, e.g. actuated by fluid means [2017-01]
E21B 43/114
. .
Perforators using direct fluid action {on the wall to be perforated}, e.g. abrasive jets [2013-01]
E21B 43/116
. .
Gun or shaped-charge perforators [2020-05]
E21B 43/117
. . .
Shaped-charge perforators (E21B 43/118 takes precedence) [2020-05]
E21B 43/118
. . .
characterised by lowering in vertical position and subsequent tilting to operating position [2013-01]
E21B 43/1185
. . .
Ignition systems [2013-01]
E21B 43/11852
. . . .
{hydraulically actuated} [2013-01]
E21B 43/11855
. . . .
{mechanically actuated, e.g. by movement of a wireline or a drop-bar (E21B 43/11852 takes precedence)} [2013-01]
E21B 43/11857
. . . .
{firing indication systems} [2013-01]
​
E21B 43/119
. .
Details, e.g. for locating perforating place or direction [2020-05]
WARNING

​
E21B 43/1193
. . .
{Dropping perforation guns after gun actuation} [2020-05]
WARNING

E21B 43/1195
. . .
{Replacement of drilling mud; decrease of undesirable shock waves} [2013-01]
E21B 43/12
.
Methods or apparatus for controlling the flow of the obtained fluid to or in wells (E21B 43/25 takes precedence; valve arrangements E21B 34/00) [2013-01]
​
E21B 43/121
. .
{Lifting well fluids (monitoring of down-hole pump systems E21B 47/008)} [2020-05]
WARNING

​
E21B 43/122
. . .
{Gas lift} [2020-05]
WARNING

​
E21B 43/123
. . . .
{Gas lift valves} [2020-05]
WARNING

​
E21B 43/1235
. . . . .
{characterised by electromagnetic actuation} [2020-05]
WARNING

​
E21B 43/124
. . .
{Adaptation of jet-pump systems} [2020-05]
WARNING

​
E21B 43/126
. . .
{Adaptations of down-hole pump systems powered by drives outside the borehole, e.g. by a rotary or oscillating drive (powered by fluid E21B 43/129)} [2020-05]
WARNING

​
E21B 43/127
. . . .
{Adaptations of walking-beam pump systems} [2020-05]
WARNING

​
E21B 43/128
. . .
{Adaptation of pump systems with down-hole electric drives} [2020-05]
WARNING

​
E21B 43/129
. . .
{Adaptations of down-hole pump systems powered by fluid supplied from outside the borehole (gas-lift E21B 43/122; jet pumps E21B 43/124)} [2020-05]
WARNING

​
E21B 43/13
. . .
{specially adapted to dewatering of wells of gas producing reservoirs, e.g. methane producing coal beds} [2020-05]
WARNING

E21B 43/14
.
Obtaining from a multiple-zone well [2013-01]
​
E21B 43/16
.
Enhanced recovery methods for obtaining hydrocarbons (fracturing E21B 43/26; obtaining slurry E21B 43/29; reclamation of contaminated soil in situ B09C {; chemical compositions therefor C09K 8/58}) [2020-05]
WARNING

E21B 43/162
. .
{Injecting fluid from longitudinally spaced locations in injection well} [2013-01]
E21B 43/164
. .
{Injecting CO2 or carbonated water (in combination with organic material C09K 8/594)} [2013-01]
E21B 43/166
. .
{Injecting a gaseous medium; Injecting a gaseous medium and a liquid medium (CO2 injection E21B 43/164; steam injection E21B 43/24)} [2013-01]
E21B 43/168
. . .
{Injecting a gaseous medium} [2013-01]
E21B 43/17
. .
Interconnecting two or more wells by fracturing or otherwise attacking the formation ({E21B 43/2405,} E21B 43/247 take precedence) [2013-01]
E21B 43/18
. .
Repressuring or vacuum methods [2013-01]
E21B 43/20
. .
Displacing by water [2013-01]
E21B 43/24
. .
using heat, e.g. steam injection (heating, cooling or insulating wells E21B 36/00 {; in combination with organic material C09K 8/592}) [2013-01]
E21B 43/2401
. . .
{by means of electricity} [2013-01]
E21B 43/2403
. . .
{by means of nuclear energy} [2020-05]
E21B 43/2405
. . .
{in association with fracturing or crevice forming processes (E21B 43/247 takes precedence)} [2013-01]
E21B 43/2406
. . .
{Steam assisted gravity drainage [SAGD]} [2013-01]
E21B 43/2408
. . . .
{SAGD in combination with other methods} [2020-08]
E21B 43/241
. . .
combined with solution mining of non-hydrocarbon minerals, e.g. solvent pyrolysis of oil shale [2013-01]
E21B 43/243
. . .
Combustion in situ [2013-01]
E21B 43/247
. . . .
in association with fracturing processes {or crevice forming processes} [2013-01]
E21B 43/248
. . . . .
using explosives [2013-01]
E21B 43/25
.
Methods for stimulating production (dump bailers E21B 27/02; vibration generating arrangements E21B 28/00; {by vibrating earth formations E21B 43/003;} chemical compositions therefor C09K 8/60) [2020-05]
E21B 43/255
. .
{including the injection of a gaseous medium as treatment fluid into the formation} [2013-01]
​
E21B 43/26
. .
by forming crevices or fractures {(chemical compositions therefor C09K 8/62)} [2020-05]
WARNING

​
E21B 43/2605
. . .
{using gas or liquefied gas} [2020-05]
WARNING

​
E21B 43/2607
. . .
{Surface equipment specially adapted for fracturing operations} [2020-05]
WARNING

E21B 43/261
. . .
{Separate steps of (1) cementing, plugging or consolidating and (2) fracturing or attacking the formation} [2013-01]
E21B 43/263
. . .
using explosives {(combustion in situ using explosives E21B 43/248)} [2017-08]
E21B 43/2635
. . . .
{by means of nuclear energy} [2020-05]
E21B 43/267
. . .
reinforcing fractures by propping {(chemical compositions therefor C09K 8/80)} [2013-01]
​
E21B 43/27
. . .
by use of eroding chemicals, e.g. acids [2020-05]
WARNING

E21B 43/28
.
Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent (E21B 43/241 takes precedence) [2020-05]
E21B 43/281
. .
{using heat} [2020-05]
E21B 43/283
. .
{in association with a fracturing process} [2013-01]
E21B 43/285
.
Melting minerals, e.g. sulfur (E21B 43/24 takes precedence; heating, cooling or insulating arrangements for wells E21B 36/00) [2013-01]
E21B 43/29
.
Obtaining a slurry of minerals, e.g. by using nozzles [2013-01]
E21B 43/292
. .
{using steerable or laterally extendable nozzles} [2013-01]
E21B 43/295
.
Gasification of minerals, e.g. for producing mixtures of combustible gases (E21B 43/243 takes precedence) [2013-01]
E21B 43/30
.
Specific pattern of wells, e.g. optimizing the spacing of wells (production satellite stations E21B 43/017) [2013-01]
E21B 43/305
. .
{comprising at least one inclined or horizontal well} [2013-01]
E21B 43/32
.
Preventing gas- or water-coning phenomena, i.e. the formation of a conical column of gas or water around wells [2020-05]
​
E21B 43/34
.
Arrangements for separating materials produced by the well (separating apparatus per se, see the relevant subclasses) [2020-05]
WARNING

​
E21B 43/35
. .
{specially adapted for separating solids (down-hole drilling fluid separation systems E21B 21/002; separating solids from drilling fluids E21B 21/065)} [2020-05]
WARNING

​
E21B 43/36
. .
Underwater separating arrangements (E21B 43/38 takes precedence) [2020-05]
WARNING

​
E21B 43/38
. .
in the well [2020-05]
WARNING

​
E21B 43/385
. . .
{by reinjecting the separated materials into an earth formation in the same well} [2020-05]
WARNING

​
E21B 43/40
. .
Separation associated with re-injection of separated materials {(E21B 43/385 takes precedence)} [2020-05]
WARNING

Automatic control, surveying or testing [2013-01]
E21B 44/00
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 (for non-automatic drilling control, see the operation controlled; automatic feeding from rack and connecting of drilling pipes E21B 19/20; controlling pressure or flow of drilling fluid E21B 21/08); Systems specially adapted for monitoring a plurality of drilling variables or conditions (means for transmitting measuring-signals from the well to the surface E21B 47/12) [2020-05]
E21B 44/005
.
{Below-ground automatic control systems} [2013-01]
E21B 44/02
.
Automatic control of the tool feed ({E21B 44/005,} E21B 44/10 take precedence) [2020-05]
E21B 44/04
. .
in response to the torque of the drive {; Measuring drilling torque (E21B 44/06 takes precedence; measuring stresses in a well bore pipe E21B 47/007)} [2020-05]
E21B 44/06
. .
in response to the flow or pressure of the motive fluid of the drive [2013-01]
E21B 44/08
. .
in response to the amplitude of the movement of the percussion tool, e.g. jump or recoil [2013-01]
E21B 44/10
.
Arrangements for automatic stopping when the tool is lifted from the working face [2020-05]
E21B 45/00
Measuring the drilling time or rate of penetration [2013-01]
​
E21B 47/00
Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B 21/08) [2020-05]
WARNING

E21B 47/001
.
for underwater installation [2020-05]
​
E21B 47/002
.
by visual inspection [2020-05]
WARNING

​
E21B 47/0025
. .
{generating an image of the borehole wall using down-hole measurements, e.g. acoustic or electric} [2020-05]
WARNING

E21B 47/003
.
Determining well or borehole volumes (determining depth E21B 47/04; diameter E21B 47/08) [2020-05]
E21B 47/005
.
Monitoring or checking of cementation quality or level [2020-05]
​
E21B 47/006
.
{Detection of corrosion or deposition of substances} [2020-05]
WARNING

E21B 47/007
.
Measuring stresses in a pipe string or casing (for locating blocked portions of pipes E21B 47/09) [2020-05]
E21B 47/008
.
Monitoring of down-hole pump systems, e.g. for the detection of "pumped-off" conditions [2020-05]
E21B 47/009
. .
Monitoring of walking-beam pump systems [2020-05]
​​
E21B 47/01
.
Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines; Protecting measuring instruments in boreholes against heat, shock, pressure or the like [2020-05]
NOTE

  • Devices for both supporting and protecting measuring instruments are only classified in E21B 47/017
WARNING

​
E21B 47/013
. .
Devices specially adapted for supporting measuring instruments on drill bits [2020-05]
WARNING

​
E21B 47/017
. .
Protecting measuring instruments [2020-05]
WARNING

​
E21B 47/0175
. . .
{Cooling arrangements} [2020-05]
WARNING

E21B 47/02
.
Determining slope or direction [2020-05]
E21B 47/022
. .
of the borehole, e.g. using geomagnetism [2020-05]
E21B 47/0224
. . .
using seismic or acoustic means [2020-05]
E21B 47/0228
. . .
using electromagnetic energy or detectors therefor [2020-05]
E21B 47/0232
. . . .
at least one of the energy sources or one of the detectors being located on or above the ground surface [2020-05]
E21B 47/0236
. . .
using a pendulum [2020-05]
E21B 47/024
. .
of devices in the borehole (E21B 47/022 takes precedence) [2013-01]
E21B 47/026
. .
of penetrated ground layers [2020-05]
E21B 47/04
.
Measuring depth or liquid level [2020-05]
E21B 47/047
. .
Liquid level (E21B 47/053 takes precedence) [2020-05]
E21B 47/053
. .
using radioactive markers [2020-05]
E21B 47/06
.
Measuring temperature or pressure [2020-05]
E21B 47/07
. .
Temperature [2020-05]
E21B 47/08
.
Measuring diameters or related dimensions at the borehole [2020-05]
E21B 47/085
. .
using radiant means, e.g. acoustic, radioactive or electromagnetic [2020-05]
E21B 47/09
.
Locating or determining the position of objects in boreholes or wells {, e.g. the position of an extending arm}; Identifying the free or blocked portions of pipes [2020-05]
E21B 47/092
. .
by detecting magnetic anomalies [2020-05]
E21B 47/095
. .
by detecting an acoustic anomalies, e.g. using mud-pressure pulses [2020-05]
E21B 47/098
. .
using impression packers, e.g. to detect recesses or perforations [2020-05]
​
E21B 47/10
.
Locating fluid leaks, intrusions or movements {(using impression packers E21B 47/098)} [2020-05]
WARNING

E21B 47/103
. .
using thermal measurements {(measurement temperature E21B 47/07)} [2020-05]
E21B 47/107
. .
using acoustic means [2020-05]
​
E21B 47/11
. .
using tracers; using radioactivity [2020-05]
WARNING

​
E21B 47/111
. . .
{using radioactivity} [2020-05]
WARNING

​
E21B 47/113
. .
using electrical indications; using light radiations [2020-05]
WARNING

​
E21B 47/114
. . .
{using light radiation} [2020-05]
WARNING

E21B 47/117
. .
Detecting leaks, e.g. from tubing, by pressure testing [2020-05]
​
E21B 47/12
.
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 [2020-05]
WARNING

E21B 47/125
. .
using earth as an electrical conductor (E21B 47/13 takes precedence) [2020-05]
E21B 47/13
. .
by electromagnetic energy, e.g. radio frequency [2020-05]
E21B 47/135
. . .
using light waves, e.g. infrared or ultraviolet waves [2020-05]
​
E21B 47/138
. .
{Devices entrained in the flow of well-bore fluid for transmitting data, control or actuation signals} [2020-05]
WARNING

E21B 47/14
. .
using acoustic waves [2013-01]
E21B 47/16
. . .
through the drill string or casing {, e.g. by torsional acoustic waves} [2017-08]
E21B 47/18
. . .
through the well fluid {, e.g. mud pressure pulse telemetry} [2017-08]
E21B 47/20
. . . .
by modulation of mud waves, e.g. by continuous modulation [2020-05]
E21B 47/22
. . . .
by negative mud pulses using a pressure relieve valve between drill pipe and annulus [2020-05]
E21B 47/24
. . . .
by positive mud pulses using a flow restricting valve within the drill pipe [2020-05]
E21B 47/26
.
Storing data down-hole, e.g. in a memory or on a record carrier [2020-05]
E21B 49/00
Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells (sampling in general G01N 1/00) [2013-01]
E21B 49/001
.
{specially adapted for underwater installations} [2013-01]
E21B 49/003
.
{by analysing drilling variables or conditions (E21B 49/005 takes precedence; systems specially adapted for monitoring a plurality of drilling variables or conditions E21B 44/00)} [2017-08]
E21B 49/005
.
{Testing the nature of borehole walls or the formation by using drilling mud or cutting data} [2020-05]
E21B 49/006
.
{Measuring wall stresses in the borehole} [2020-05]
E21B 49/008
.
{by injection test; by analysing pressure variations in an injection or production test, e.g. for estimating the skin factor (measuring pressure E21B 47/06)} [2020-05]
E21B 49/02
.
by mechanically taking samples of the soil (apparatus for obtaining undisturbed cores E21B 25/00; investigation of foundation soil in situ E02D 1/00) [2013-01]
E21B 49/025
. .
{of underwater soil, e.g. with grab devices} [2020-05]
E21B 49/04
. .
using explosives in boreholes; using projectiles penetrating the wall [2020-05]
E21B 49/06
. .
using side-wall drilling tools {pressing} or scrapers [2020-05]
E21B 49/08
.
Obtaining fluid samples or testing fluids, in boreholes or wells [2020-05]
​
E21B 49/081
. .
{with down-hole means for trapping a fluid sample (E21B 49/10 takes precedence)} [2020-05]
WARNING

​
E21B 49/0813
. . .
{Sampling valve actuated by annulus pressure changes} [2020-05]
WARNING

​
E21B 49/0815
. . .
{Sampling valve actuated by tubing pressure changes} [2020-05]
WARNING

E21B 49/082
. . .
{Wire-line fluid samplers (E21B 49/083 takes precedence)} [2013-01]
​
E21B 49/083
. . .
{Samplers adapted to be lowered into or retrieved from a landing nipple, e.g. for testing a well without removing the drill string} [2020-05]
WARNING

E21B 49/084
. .
{with means for conveying samples through pipe to surface} [2013-01]
E21B 49/086
. .
{Withdrawing samples at the surface} [2013-01]
​
E21B 49/087
. .
{Well testing, e.g. testing for reservoir productivity or formation parameters} [2020-05]
WARNING

​
E21B 49/0875
. . .
{determining specific fluid parameters} [2020-05]
WARNING

E21B 49/088
. . .
{combined with sampling} [2013-01]
E21B 49/10
. .
using side-wall fluid samplers or testers [2013-01]
​
E21B 2200/00
Special features related to earth drilling for obtaining oil, gas or water [2020-05]
WARNING

​
E21B 2200/01
.
Sealings characterised by their shape [2020-05]
WARNING

​
E21B 2200/02
.
Down-hole chokes or valves for variably regulating fluid flow [2020-05]
WARNING

​
E21B 2200/03
.
Valves operated by gear mechanisms, e.g. rack and pinion mechanisms [2020-05]
WARNING

​
E21B 2200/04
.
Ball valves [2020-05]
WARNING

​
E21B 2200/05
.
Flapper valves [2020-05]
WARNING

​
E21B 2200/06
.
Sleeve valves [2020-05]
WARNING

​
E21B 2200/08
.
Down-hole devices using materials which decompose under well-bore conditions [2020-05]
WARNING

​
E21B 2200/09
.
Detecting, eliminating, preventing liquid slugs in production pipes [2020-05]
WARNING

​
E21B 2200/20
.
Computer models or simulations, e.g. for reservoirs under production, drill bits [2020-05]
WARNING

​
E21B 2200/22
.
Fuzzy logic, artificial intelligence, neural networks or the like [2020-05]
WARNING