|  | E |
SECTION E — FIXED CONSTRUCTIONS

EARTH OR ROCK DRILLING; MINING

|  | E21 |
EARTH OR ROCK DRILLING; MINING

|  | E21 |
Note(s) In this class, the following term is used with the meaning indicated: "drilling" covers boring and vice versa.

|  | E21B |
EARTH OR ROCK DRILLING (mining, quarrying Fulltext... Hierarchy... Expanded...E21C; making shafts, driving galleries or tunnels Fulltext... Hierarchy... Expanded...E21D); OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS [5]

|  | E21B |
Note(s) This subclass covers: [7] primarily equipment for drilling of earth or rock in their natural formation; [7] similar equipment for drilling of man-made structures in situ, e.g. of road surfaces or concrete structures. [7] This subclass does not cover: [7] hand-held drilling machines, e.g. for domestic use; [7] drilling equipment for manufacturing operations, i.e. where an article is worked, e.g. for further processing; [7] which are covered by relevant subclasses of section B, e.g. Fulltext... Hierarchy... Expanded...B23B; [7] compositions for drilling of boreholes or wells or for treating boreholes or wells, which compositions are covered by group Fulltext... Hierarchy... Expanded...C09K 8/00, e.g. compositions for enhanced recovery methods for obtaining hydrocarbons Fulltext... Hierarchy... Expanded...C09K 8/58. [8] Processes using enzymes or micro-organisms in order to: [8] liberate, separate or purify a pre-existing compound or composition, or to [8] treat textiles or clean solid surfaces of materials [8] are further classified in subclass Fulltext... Hierarchy... Expanded...C12S. [8]

|  | E21B |
Subclass index
METHODS OR APPARATUS FOR DRILLING | 1/00 - 7/00
DRILLING TOOLS; ACCESSORIES THEREFOR | 10/00, 11/00; 12/00
OTHER EQUIPMENT OR DETAILS FOR DRILLING; WELL EQUIPMENT OR MAINTENANCE |
Derricks; drilling rods or the like | 15/00; 17/00, 19/00
Flushing or cleaning; sealing; heating or cooling | 21/00, 37/00; 33/00; 36/00
Valve arrangements; fire-fighting | 34/00; 35/00
Other equipment or details | 23/00 - 31/00, 40/00, 41/00
OBTAINING FLUIDS FROM WELLS | 43/00
CONTROL; SURVEYING OR TESTING | 44/00; 45/00 - 49/00

|  | E21B 1/00 - E21B 7/00 |
Methods or apparatus for drilling

P:210 |  | E21B 1/00 |
Percussion drilling (drives used in the borehole Fulltext... Hierarchy... Expanded...E21B 4/00) [3]

|  | E21B 1/02 |
· | Surface drives for drop hammers, e.g. with a cable [1,7]

|  | E21B 1/04 |
· · | Devices for reversing the movement of the rod or cable at the surface

|  | E21B 1/12 |
· | with a reciprocating impulse member (Fulltext... Hierarchy... Expanded...E21B 1/02, Fulltext... Hierarchy... Expanded...E21B 1/38 take precedence) [7]

|  | E21B 1/14 |
· · | driven by a rotating mechanism [7]

|  | E21B 1/16 |
· · · | with spring-mounted reciprocating masses, e.g. with air cushion [7]

|  | E21B 1/18 |
· · · · | with elastic joining of the drive to the push-rod by double buffer springs [7]

|  | E21B 1/20 |
· · · | formed as centrifugal hammers [7]

|  | E21B 1/22 |
· · | driven by electromagnets [7]

|  | E21B 1/24 |
· · | the impulse member being a piston driven directly by fluid pressure [7]

|  | E21B 1/26 |
· · · | by liquid pressure [7]

|  | E21B 1/28 |
· · · · | working with pulses [7]

|  | E21B 1/30 |
· · · | by air, steam or gas pressure [7]

|  | E21B 1/32 |
· · · · | working with pulses [7]

|  | E21B 1/34 |
· · · · · | the impulse member being a piston of an internal-combustion engine [7]

|  | E21B 1/36 |
· | Tool-carrier piston type, i.e. in which the tool is connected to an impulse member [7]

|  | E21B 1/38 |
· | Hammer piston type, i.e. in which the tool bit or anvil is hit by an impulse member [7]

P:200 |  | E21B 3/00 |
Rotary drilling (drives used in the borehole Fulltext... Hierarchy... Expanded...E21B 4/00; rotary drilling machines in general Fulltext... Hierarchy... Expanded...B23B) [3]

|  | E21B 3/02 |
· | Surface drives for rotary drilling

|  | E21B 3/025 |
· · | with a to-and-fro rotation of the tool [7]

|  | E21B 3/03 |
· · | with an intermittent unidirectional rotation of the tool [7]

|  | E21B 3/035 |
· · | with slipping or elastic transmission [7]

|  | E21B 3/04 |
· · | Rotary tables

|  | E21B 3/06 |
· · · | Adaptation of rotary draw works to drive rotary tables (connecting or disconnecting couplings or joints Fulltext... Hierarchy... Expanded...E21B 19/16; rope, cable, or chain winding mechanisms, capstans Fulltext... Hierarchy... Expanded...B66D) [3]

P:180 |  | E21B 4/00 |
Drives used in the borehole [3]

|  | E21B 4/02 |
· | Fluid rotary type drives (hydraulic turbines for drilling wells Fulltext... Hierarchy... Expanded...F03B 13/02) [3]

|  | E21B 4/04 |
· | Electric drives (Fulltext... Hierarchy... Expanded...E21B 4/12 takes precedence) [3]

|  | E21B 4/06 |
· | Down-hole impacting means, e.g. hammers (percussion drill bits Fulltext... Hierarchy... Expanded...E21B 10/36; boring rams Fulltext... Hierarchy... Expanded...E21B 11/02; releasing-jars Fulltext... Hierarchy... Expanded...E21B 31/107) [3]

|  | E21B 4/08 |
· · | impact being obtained by gravity only, e.g. with lost-motion connection [3]

|  | E21B 4/10 |
· · | continuous unidirectional rotary motion of shaft or drilling pipe effecting consecutive impacts [3]

|  | E21B 4/12 |
· · | Electrically operated hammers [3]

|  | E21B 4/14 |
· · | Fluid operated hammers [3]

|  | E21B 4/16 |
· | Plural down-hole drives, e.g. for combined percussion and rotary drilling (Fulltext... Hierarchy... Expanded...E21B 4/10 takes precedence); Drives for multi-bit drilling units [3]

|  | E21B 4/18 |
· | Anchoring or feeding in the borehole [3,7]

|  | E21B 4/20 |
· | combined with surface drive (Fulltext... Hierarchy... Expanded...E21B 4/10 takes precedence) [3]

P:190 |  | E21B 6/00 |
Drives for drilling with combined rotary and percussive action (drives used in the borehole Fulltext... Hierarchy... Expanded...E21B 4/00; portable percussive machines with superimposed rotation Fulltext... Hierarchy... Expanded...B25D 16/00) [3]

|  | E21B 6/02 |
· | the rotation being continuous [7]

|  | E21B 6/04 |
· · | Separate drives for percussion and rotation [7]

|  | E21B 6/06 |
· | the rotation being intermittent, e.g. obtained by a ratchet device [7]

|  | E21B 6/08 |
· · | Separate drives for percussion and rotation [7]

P:150 |  | E21B 7/00 |
Special methods or apparatus for drilling (supports for the drilling machine, e.g. derricks or masts, Fulltext... Hierarchy... Expanded...E21B 15/00) [1,7]

|  | E21B 7/02 |
· | Drilling rigs characterised by means for land transport, e.g. skid mounting or wheel mounting (portable drilling rigs for use on underwater floors Fulltext... Hierarchy... Expanded...E21B 7/124) [1,7]

|  | E21B 7/04 |
· | Directional drilling

|  | E21B 7/06 |
· · | Deflecting the direction of boreholes

|  | E21B 7/08 |
· · · | Special apparatus for deflecting the boring, e.g. special drill bits, knuckle joints, whipstocks (directional window cutting Fulltext... Hierarchy... Expanded...E21B 29/06; deflecting the direction of fishing tools Fulltext... Hierarchy... Expanded...E21B 31/14)

|  | E21B 7/10 |
· · | Correction of deflected boreholes

|  | E21B 7/12 |
· | Underwater drilling (telescoping joints Fulltext... Hierarchy... Expanded...E21B 17/07; using heave compensators Fulltext... Hierarchy... Expanded...E21B 19/09; well heads specially adapted for underwater installations Fulltext... Hierarchy... Expanded...E21B 33/035) [1,7]

|  | E21B 7/124 |
· · | with underwater tool drive prime mover, e.g. portable drilling rigs for use on underwater floors [3]

|  | E21B 7/128 |
· · | from floating support with independent underwater anchored guide base [3]

|  | E21B 7/132 |
· · | from underwater buoyant support [3]

|  | E21B 7/136 |
· · | from non-buoyant support (Fulltext... Hierarchy... Expanded...E21B 7/124 takes precedence) [3]

|  | E21B 7/14 |
· | Drilling by use of heat, e.g. flame drilling

|  | E21B 7/15 |
· · | of electrically generated heat [3]

|  | E21B 7/16 |
· | Applying separate balls or pellets by the pressure of the drill, so-called shot-drilling

|  | E21B 7/18 |
· | Drilling by liquid or gas jets, with or without entrained pellets (Fulltext... Hierarchy... Expanded...E21B 7/14 takes precedence; hydraulic monitors Fulltext... Hierarchy... Expanded...E21C 45/00) [5]

|  | 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 Fulltext... Hierarchy... Expanded...E21B 3/025; placing piles Fulltext... Hierarchy... Expanded...E02D 7/00; sinking shafts while moving the lining downwards Fulltext... Hierarchy... Expanded...E21D 1/08) [3]

|  | E21B 7/24 |
· | Drilling using vibrating or oscillating means, e.g. out-of-balance masses (percussion drilling Fulltext... Hierarchy... Expanded...E21B 1/00) [3]

|  | E21B 7/26 |
· | Drilling without earth removal, e.g. with self-propelled burrowing devices (Fulltext... Hierarchy... Expanded...E21B 7/30 takes precedence; down-hole drives Fulltext... Hierarchy... Expanded...E21B 4/00) [3,6]

|  | E21B 7/28 |
· | Enlarging drilled holes, e.g. by counterboring (drill bits for enlarging the borehole Fulltext... Hierarchy... Expanded...E21B 10/26) [3]

|  | E21B 7/30 |
· · | without earth removal [6]

|  | E21B 10/00 - E21B 12/00 |
Drilling tools

P:260 |  | E21B 10/00 |
Drill bits (specially adapted for deflecting the direction of boring Fulltext... Hierarchy... Expanded...E21B 7/08; with means for collecting substances Fulltext... Hierarchy... Expanded...E21B 27/00) [3,8]

|  | E21B 10/02 |
· | Core bits (characterised by wear resisting parts Fulltext... Hierarchy... Expanded...E21B 10/46; obtaining undisturbed cores Fulltext... Hierarchy... Expanded...E21B 25/00) [3]

|  | E21B 10/04 |
· · | with core destroying means [3]

|  | E21B 10/06 |
· · | Roller core bits [3]

|  | E21B 10/08 |
· | Roller bits (roller core bits Fulltext... Hierarchy... Expanded...E21B 10/06; with leading portion Fulltext... Hierarchy... Expanded...E21B 10/26; characterised by wear resisting parts Fulltext... Hierarchy... Expanded...E21B 10/46) [3]

|  | E21B 10/10 |
· · | with roller axle supported at both ends (with disc cutters Fulltext... Hierarchy... Expanded...E21B 10/12) [3]

|  | E21B 10/12 |
· · | with disc cutters [3]

|  | E21B 10/14 |
· · | combined with non-rolling cutters other than of leading-portion type [3]

|  | E21B 10/16 |
· · | characterised by tooth form or arrangement [3]

|  | E21B 10/18 |
· · | characterised by conduits or nozzles for drilling fluids (drilling fluid supply to the bearings Fulltext... Hierarchy... Expanded...E21B 10/23) [3,8]

|  | E21B 10/20 |
· · | characterised by detachable or adjustable parts, e.g. legs or axles (cross axle roller bits Fulltext... Hierarchy... Expanded...E21B 10/10) [3]

|  | E21B 10/22 |
· · | characterised by bearing, lubrication or sealing details [3,8]

|  | E21B 10/23 |
· · · | with drilling fluid supply to the bearings [8]

|  | E21B 10/24 |
· · · | characterised by lubricating details (Fulltext... Hierarchy... Expanded...E21B 10/23 takes precedence) [3,8]

|  | E21B 10/25 |
· · · | characterised by sealing details [8]

|  | 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 Fulltext... Hierarchy... Expanded...E21B 10/40; augers with leading portion Fulltext... Hierarchy... Expanded...E21B 10/44) [3]

|  | E21B 10/28 |
· · | with non-expansible roller cutters [3]

|  | E21B 10/30 |
· · · | Longitudinal axis roller reamers, e.g. reamer stabilisers [3]

|  | E21B 10/32 |
· · | with expansible cutting tools [3]

|  | E21B 10/34 |
· · · | of roller-cutter type [3]

|  | E21B 10/36 |
· | Percussion drill bits (characterised by wear resisting parts Fulltext... Hierarchy... Expanded...E21B 10/46) [3]

|  | E21B 10/38 |
· · | characterised by conduits or nozzles for drilling fluids [3]

|  | E21B 10/40 |
· · | with leading portion [3]

|  | 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 Fulltext... Hierarchy... Expanded...E21B 10/46, by conduits or nozzles for drilling fluid Fulltext... Hierarchy... Expanded...E21B 10/60, by detachable parts Fulltext... Hierarchy... Expanded...E21B 10/62) [3,8]

|  | E21B 10/43 |
· · | characterised by the arrangement of teeth or other cutting elements [8]

|  | E21B 10/44 |
· | Bits with helical conveying portion, e.g. screw type bits; Augers with leading portion or with detachable parts (Fulltext... Hierarchy... Expanded...E21B 10/42 takes precedence; drilling rods with helical structure Fulltext... Hierarchy... Expanded...E21B 17/22) [3,8]

|  | E21B 10/46 |
· | characterised by wear resisting parts, e.g. diamond inserts [3]

|  | E21B 10/48 |
· · | the bit being of core type [3]

|  | E21B 10/50 |
· · | the bit being of roller type [3]

|  | E21B 10/52 |
· · · | with chisel- or button-type inserts [3]

|  | E21B 10/54 |
· · | the bit being of the rotary drag type, e.g. fork-type bits [3,8]

|  | E21B 10/55 |
· · · | with preformed cutting elements (inserts per se Fulltext... Hierarchy... Expanded...E21B 10/56, Fulltext... Hierarchy... Expanded...E21B 10/58) [8]

|  | E21B 10/56 |
· · | Button-type inserts (Fulltext... Hierarchy... Expanded...E21B 10/52 takes precedence) [3]

|  | E21B 10/567 |
· · · | with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts [8]

|  | E21B 10/573 |
· · · · | characterised by support details, e.g. the substrate construction or the interface between the substrate and the cutting element [8]

|  | E21B 10/58 |
· · | Chisel-type inserts (Fulltext... Hierarchy... Expanded...E21B 10/52, Fulltext... Hierarchy... Expanded...E21B 10/54 take precedence) [3]

|  | E21B 10/60 |
· | characterised by conduits or nozzles for drilling fluids (for roller bits Fulltext... Hierarchy... Expanded...E21B 10/18; for percussion drill bits Fulltext... Hierarchy... Expanded...E21B 10/38) [3]

|  | E21B 10/61 |
· · | characterised by nozzle structure [8]

|  | E21B 10/62 |
· | characterised by parts, e.g. cutting elements, which are detachable or adjustable (Fulltext... Hierarchy... Expanded...E21B 10/64 takes precedence; for roller bits Fulltext... Hierarchy... Expanded...E21B 10/20; for augers Fulltext... Hierarchy... Expanded...E21B 10/44) [3,8]

|  | E21B 10/627 |
· · | with plural detachable cutting elements [8]

|  | E21B 10/633 |
· · · | independently detachable [8]

|  | 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 Fulltext... Hierarchy... Expanded...E21B 25/02) [3]

|  | E21B 10/66 |
· · | the cutting element being movable through the drilling pipe and laterally shiftable [3]

P:280 |  | E21B 11/00 |
Other drilling tools

|  | E21B 11/02 |
· | Boring rams (percussion drives used in the borehole Fulltext... Hierarchy... Expanded...E21B 4/06; percussion drill bits Fulltext... Hierarchy... Expanded...E21B 10/36)

|  | E21B 11/04 |
· | Boring grabs

|  | E21B 11/06 |
· | with driven cutting chains or similarly-driven tools

P:290 |  | E21B 12/00 |
Accessories for drilling tools [3]

|  | E21B 12/02 |
· | Wear indicators [3]

|  | E21B 12/04 |
· | Drill bit protectors [3]

|  | E21B 12/06 |
· | Mechanical cleaning devices [3]

|  | E21B 15/00 - E21B 41/00 |
Other equipment or details for drilling; Well equipment or well maintenance

P:230 |  | E21B 15/00 |
Supports for the drilling machine, e.g. derricks or masts [1,7]

|  | E21B 15/02 |
· | specially adapted for underwater drilling (Fulltext... Hierarchy... Expanded...E21B 15/04 takes precedence; floating drilling platforms Fulltext... Hierarchy... Expanded...B63B 35/44; drilling platforms on legs Fulltext... Hierarchy... Expanded...E02B 17/00) [3]

|  | E21B 15/04 |
· | specially adapted for directional drilling, e.g. slant hole rigs [3]

P:270 |  | E21B 17/00 |
Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Casings; Tubings (rod couplings in general Fulltext... Hierarchy... Expanded...F16D; tubes or tube couplings in general Fulltext... Hierarchy... Expanded...F16L)

|  | E21B 17/01 |
· | Risers (riser connectors Fulltext... Hierarchy... Expanded...E21B 33/038) [3]

|  | E21B 17/02 |
· | Couplings; Joints

|  | E21B 17/03 |
· · | between drilling rod or pipe and drill motor, e.g. between drilling rod and hammer [7]

|  | E21B 17/04 |
· · | between rod and bit, or between rod and rod

|  | E21B 17/042 |
· · · | threaded

|  | E21B 17/043 |
· · · · | with locking means

|  | E21B 17/046 |
· · · | with ribs, pins, or jaws, and complementary grooves or the like, e.g. bayonet catches

|  | E21B 17/05 |
· · · | Swivel joints

|  | E21B 17/06 |
· · · | Releasing-joints, e.g. safety joints

|  | E21B 17/07 |
· · · | Telescoping joints for varying drill string lengths; Shock absorbers (heave compensators in the derrick Fulltext... Hierarchy... Expanded...E21B 19/09; releasing-jars Fulltext... Hierarchy... Expanded...E21B 31/107) [3]

|  | E21B 17/08 |
· · | Casing joints

|  | E21B 17/10 |
· | Wear protectors; Centralising devices (drives used in the borehole with anchoring means Fulltext... Hierarchy... Expanded...E21B 4/18; guiding or centralising devices outside the borehole Fulltext... Hierarchy... Expanded...E21B 19/24)

|  | E21B 17/12 |
· · | Devices for placing or drawing out wear protectors

|  | E21B 17/14 |
· | Casing shoes

|  | E21B 17/16 |
· | Drill collars [3]

|  | E21B 17/18 |
· | Pipes provided with plural fluid passages (circulation of drilling fluid by means of such pipes Fulltext... Hierarchy... Expanded...E21B 21/12) [3]

|  | E21B 17/20 |
· | Flexible or articulated drilling pipes [3]

|  | E21B 17/22 |
· | Rods or pipes with helical structure (drill bits with helical conveying portion Fulltext... Hierarchy... Expanded...E21B 10/44) [3]

P:220 |  | 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 Fulltext... Hierarchy... Expanded...E21B 1/02, Fulltext... Hierarchy... Expanded...E21B 3/02)

|  | E21B 19/02 |
· | Rod or cable suspensions (load-engaging elements for hoisting or lowering purposes in general Fulltext... Hierarchy... Expanded...B66C 1/00; crown blocks or pulley blocks Fulltext... Hierarchy... Expanded...B66D; cable guides Fulltext... Hierarchy... Expanded...B66D 1/36)

|  | E21B 19/04 |
· · | Hooks

|  | E21B 19/06 |
· · | Elevators, i.e. rod- or tube-gripping devices

|  | E21B 19/07 |
· · · | Slip-type elevators (slips in rotary tables Fulltext... Hierarchy... Expanded...E21B 19/10)

|  | E21B 19/08 |
· | Apparatus for feeding the rods or cables (Fulltext... Hierarchy... Expanded...E21B 19/22 takes precedence; automatic feed Fulltext... Hierarchy... Expanded...E21B 44/02; hoisting drums Fulltext... Hierarchy... Expanded...B66D); Apparatus for increasing or decreasing the pressure on the drilling tool; Apparatus for counterbalancing the weight of the rods [3,7]

|  | E21B 19/081 |
· · | Screw-and-nut feed mechanisms [7]

|  | E21B 19/083 |
· · | Cam, rack or like feed mechanisms [7]

|  | E21B 19/084 |
· · | with flexible drawing means, e.g. cables [7]

|  | E21B 19/086 |
· · | with a fluid-actuated cylinder (Fulltext... Hierarchy... Expanded...E21B 19/084, Fulltext... Hierarchy... Expanded...E21B 19/087, Fulltext... Hierarchy... Expanded...E21B 19/09 take precedence) [7]

|  | E21B 19/087 |
· · | by means of a swinging arm [7]

|  | E21B 19/089 |
· · | with a spring or an additional weight [7]

|  | E21B 19/09 |
· · | specially adapted for drilling underwater formations from a floating support using heave compensators supporting the drill string (drilling-pipe telescoping joints Fulltext... Hierarchy... Expanded...E21B 17/07) [3]

|  | E21B 19/10 |
· | Slips; Spiders

|  | E21B 19/12 |
· | Rope clamps (rope clamps in general Fulltext... Hierarchy... Expanded...F16G 11/00)

|  | E21B 19/14 |
· | Racks, ramps, troughs or bins, for holding the lengths of rod singly or connected; Handling between storage place and borehole (Fulltext... Hierarchy... Expanded...E21B 19/20, Fulltext... Hierarchy... Expanded...E21B 19/22 take precedence) [3]

|  | E21B 19/15 |
· · | Racking of rods in horizontal position; Handling between horizontal and vertical position [3]

|  | E21B 19/16 |
· | Connecting or disconnecting pipe couplings or joints (Fulltext... Hierarchy... Expanded...E21B 19/20 takes precedence; pipe wrenches or the like Fulltext... Hierarchy... Expanded...B25B) [3]

|  | E21B 19/18 |
· | Connecting or disconnecting drill bit and drilling pipe [3]

|  | E21B 19/20 |
· | Combined feeding from rack and connecting, e.g. automatically [3]

|  | E21B 19/22 |
· | Handling reeled pipe or rod units, e.g. flexible drilling pipes [3]

|  | E21B 19/24 |
· | Guiding or centralising devices for drilling rods or pipes [7]

P:100 |  | 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 Fulltext... Hierarchy... Expanded...E21B 31/03; well drilling compositions Fulltext... Hierarchy... Expanded...C09K 8/02) [2,7]

|  | E21B 21/01 |
· | Arrangements for handling drilling fluids or cuttings outside the borehole, e.g. mud boxes (arrangements for treating drilling fluids Fulltext... Hierarchy... Expanded...E21B 21/06) [7]

|  | E21B 21/015 |
· · | Means engaging the bore entrance, e.g. hoods for collecting dust [7]

|  | E21B 21/02 |
· | Swivel joints in hose lines

|  | E21B 21/06 |
· | Arrangements for treating drilling fluids outside the borehole (treating steps per se, see the relevant subclasses) [3]

|  | E21B 21/07 |
· · | for treating dust-laden gaseous fluids [7]

|  | 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 Fulltext... Hierarchy... Expanded...E21B 21/10) [3]

|  | E21B 21/10 |
· | Valves arrangements in drilling-fluid circulation systems (valves in general Fulltext... Hierarchy... Expanded...F16K) [3]

|  | E21B 21/12 |
· | using drilling pipes with plural fluid passages, e.g. closed circulation systems (pipes with plural fluid passages Fulltext... Hierarchy... Expanded...E21B 17/18) [3]

|  | E21B 21/14 |
· | using liquids and gases, e.g. foams [3]

|  | E21B 21/16 |
· | using gaseous fluids (Fulltext... Hierarchy... Expanded...E21B 21/14 takes precedence; arrangements for handling drilling fluids outside the borehole Fulltext... Hierarchy... Expanded...E21B 21/01; arrangements for treating drilling fluids Fulltext... Hierarchy... Expanded...E21B 21/06) [7]

|  | E21B 21/18 |
· | Preventing exhaust air from the drill motor from blowing-off towards the working face [7]

P:80 |  | E21B 23/00 |
Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells (setting of casings, screens, or liners Fulltext... Hierarchy... Expanded...E21B 43/10)

|  | E21B 23/01 |
· | for anchoring the tools or the like (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...E21B 23/02-E21B 23/06 take precedence; anchoring of drives in the borehole Fulltext... Hierarchy... Expanded...E21B 4/18) [6]

|  | E21B 23/02 |
· | for locking the tools or the like in landing nipples or in recesses between adjacent sections of tubing (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...E21B 23/03-E21B 23/06 take precedence) [3]

|  | E21B 23/03 |
· | for setting the tools into, or removing the tools from, laterally offset landing nipples or pockets [3]

|  | E21B 23/04 |
· | operated by fluid means, e.g. actuated by explosion (Fulltext... Hierarchy... Expanded...E21B 23/06, Fulltext... Hierarchy... Expanded...E21B 23/08 take precedence) [3]

|  | E21B 23/06 |
· | for setting packers

|  | E21B 23/08 |
· | Introducing or running tools by fluid pressure, e.g. through-the-flow-line tool systems (special provisions on heads therefor Fulltext... Hierarchy... Expanded...E21B 33/068; cementing plugs Fulltext... Hierarchy... Expanded...E21B 33/16; scrapers operated by fluid pressure Fulltext... Hierarchy... Expanded...E21B 37/04) [3]

|  | E21B 23/10 |
· · | Tools specially adapted therefor [3]

|  | E21B 23/12 |
· · | Tool diverters [3]

|  | E21B 23/14 |
· | for displacing a cable or a cable-operated tool, e.g. for logging or perforating operations in deviated wells (by fluid pressure Fulltext... Hierarchy... Expanded...E21B 23/08; provision on well heads for introducing or removing cable-operated tools Fulltext... Hierarchy... Expanded...E21B 33/072, Fulltext... Hierarchy... Expanded...E21B 33/076) [6]

P:40 |  | E21B 25/00 |
Apparatus for obtaining or removing undisturbed cores, e.g. core barrels, core extractors (core bits Fulltext... Hierarchy... Expanded...E21B 10/02; using explosives or projectiles in boreholes Fulltext... Hierarchy... Expanded...E21B 49/04; side-wall sampling or coring Fulltext... Hierarchy... Expanded...E21B 49/06)

|  | E21B 25/02 |
· | the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe (retrievable drill bits Fulltext... Hierarchy... Expanded...E21B 10/64) [3]

|  | E21B 25/04 |
· · | the core receiver having a core forming cutting edge or element, e.g. punch type core barrels [3]

|  | E21B 25/06 |
· | the core receiver having a flexible liner or inflatable retaining means [3]

|  | E21B 25/08 |
· | Coating, freezing, consolidating cores (Fulltext... Hierarchy... Expanded...E21B 25/06 takes precedence); Recovering uncontaminated cores or cores at formation pressure [3]

|  | E21B 25/10 |
· | Formed core retaining or severing means (Fulltext... Hierarchy... Expanded...E21B 25/06, Fulltext... Hierarchy... Expanded...E21B 25/08 take precedence) [3]

|  | E21B 25/12 |
· · | of the sliding wedge type [3]

|  | E21B 25/14 |
· · | mounted on pivot transverse to core axis [3]

|  | E21B 25/16 |
· | for obtaining oriented cores [3]

|  | E21B 25/18 |
· | the core receiver being specially adapted for operation under water [3]

P:250 |  | E21B 27/00 |
Containers for collecting or depositing substances in boreholes or wells, e.g. bailers for collecting mud or sand; Drill bits with means for collecting substances, e.g. valve drill bits [6,8]

|  | E21B 27/02 |
· | Dump bailers, i.e. containers for depositing substances, e.g. cement or acids [6,8]

|  | E21B 27/04 |
· | where the collecting or depositing means include helical conveying means [8]

P:0 |  | E21B 28/00 |
Vibration generating arrangements for boreholes or wells, e.g. for stimulating production (for drilling Fulltext... Hierarchy... Expanded...E21B 7/24; for transmitting measuring-signals Fulltext... Hierarchy... Expanded...E21B 47/14; for geophysical measurements Fulltext... Hierarchy... Expanded...G01V 1/02) [6]

P:60 |  | 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 Fulltext... Hierarchy... Expanded...E21B 43/11); Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground

|  | E21B 29/02 |
· | by explosives or by thermal or chemical means (destroying objects in boreholes or wells by explosives Fulltext... Hierarchy... Expanded...E21B 31/16)

|  | E21B 29/04 |
· | Cutting of wire lines or the like (Fulltext... Hierarchy... Expanded...E21B 29/02 takes precedence) [3]

|  | E21B 29/06 |
· | Cutting windows, e.g. directional window cutters for whipstock operations (Fulltext... Hierarchy... Expanded...E21B 29/08 takes precedence; whipstocks Fulltext... Hierarchy... Expanded...E21B 7/08) [3]

|  | E21B 29/08 |
· | Cutting or deforming pipes to control fluid flow (blow-out preventers Fulltext... Hierarchy... Expanded...E21B 33/06) [3]

|  | E21B 29/10 |
· | Reconditioning of well casings, e.g. straightening [3]

|  | E21B 29/12 |
· | specially adapted for underwater installations (Fulltext... Hierarchy... Expanded...E21B 29/08 takes precedence) [3]

P:90 |  | E21B 31/00 |
Fishing for or freeing objects in boreholes or wells (provisions on well heads for introducing or removing objects Fulltext... Hierarchy... Expanded...E21B 33/068; locating or determining the position of objects in boreholes or wells Fulltext... Hierarchy... Expanded...E21B 47/09)

|  | E21B 31/03 |
· | Freeing by flushing [3]

|  | E21B 31/06 |
· | using magnetic means [3]

|  | E21B 31/08 |
· | using junk baskets or the like [3]

|  | E21B 31/107 |
· | using impact means for releasing stuck parts, e.g. jars (telescoping joints Fulltext... Hierarchy... Expanded...E21B 17/07) [3]

|  | E21B 31/113 |
· · | hydraulically operated [3]

|  | E21B 31/12 |
· | Grappling tools, e.g. tongs or grabs

|  | E21B 31/14 |
· · | with means deflecting the direction of the tool, e.g. by use of knuckle joints (apparatus for deflecting the boring Fulltext... Hierarchy... Expanded...E21B 7/08) [3]

|  | E21B 31/16 |
· · | combined with cutting or destroying means (cutting or destroying means per se Fulltext... Hierarchy... Expanded...E21B 29/00) [3]

|  | E21B 31/18 |
· · | gripping externally, e.g. overshot [3]

|  | E21B 31/20 |
· · | gripping internally, e.g. fishing spears [3]

P:140 |  | E21B 33/00 |
Sealing or packing boreholes or wells

|  | E21B 33/02 |
· | Surface sealing or packing

|  | E21B 33/03 |
· · | Well heads; Setting-up thereof (valve arrangements therefor Fulltext... Hierarchy... Expanded...E21B 34/02)

|  | E21B 33/035 |
· · · | specially adapted for underwater installations (Fulltext... Hierarchy... Expanded...E21B 33/043, Fulltext... Hierarchy... Expanded...E21B 33/064, Fulltext... Hierarchy... Expanded...E21B 33/076 take precedence) [3]

|  | E21B 33/037 |
· · · · | Protective housings therefor [3]

|  | 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 Fulltext... Hierarchy... Expanded...E21B 43/013) [3]

|  | E21B 33/04 |
· · · | Casing heads; Suspending casings or tubings in well heads (setting of casings in wells Fulltext... Hierarchy... Expanded...E21B 43/10)

|  | E21B 33/043 |
· · · · | specially adapted for underwater well heads (Fulltext... Hierarchy... Expanded...E21B 33/047 takes precedence) [3]

|  | E21B 33/047 |
· · · · | for plural tubing strings [3]

|  | E21B 33/05 |
· · · · | Cementing-heads, e.g. having provision for introducing cementing plugs

|  | E21B 33/06 |
· · · | Blow-out preventers [3]

|  | E21B 33/064 |
· · · · | specially adapted for underwater well heads (connectors therefor Fulltext... Hierarchy... Expanded...E21B 33/038) [3]

|  | E21B 33/068 |
· · · | having provision for introducing objects or fluids into, or removing objects from, wells (cementing-heads Fulltext... Hierarchy... Expanded...E21B 33/05) [3]

|  | E21B 33/072 |
· · · · | for cable-operated tools (Fulltext... Hierarchy... Expanded...E21B 33/076 takes precedence) [3]

|  | E21B 33/076 |
· · · · | specially adapted for underwater installations [3]

|  | E21B 33/08 |
· · | Wipers; Oil savers

|  | E21B 33/10 |
· | in the borehole

|  | E21B 33/12 |
· · | Packers; Plugs (used for cementing Fulltext... Hierarchy... Expanded...E21B 33/134, Fulltext... Hierarchy... Expanded...E21B 33/16)

|  | E21B 33/122 |
· · · | Multiple-string packers

|  | E21B 33/124 |
· · · | Units with longitudinally-spaced plugs for isolating the intermediate space

|  | E21B 33/126 |
· · · | with fluid-pressure-operated elastic cup or skirt (Fulltext... Hierarchy... Expanded...E21B 33/122, Fulltext... Hierarchy... Expanded...E21B 33/124 take precedence)

|  | E21B 33/127 |
· · · | with inflatable sleeve (Fulltext... Hierarchy... Expanded...E21B 33/122, Fulltext... Hierarchy... Expanded...E21B 33/124 take precedence)

|  | E21B 33/128 |
· · · | with a member expanded radially by axial pressure (Fulltext... Hierarchy... Expanded...E21B 33/122, Fulltext... Hierarchy... Expanded...E21B 33/124 take precedence)

|  | E21B 33/129 |
· · · | with mechanical slips for hooking into the casing (Fulltext... Hierarchy... Expanded...E21B 33/122, Fulltext... Hierarchy... Expanded...E21B 33/124 take precedence)

|  | E21B 33/1295 |
· · · · | actuated by fluid pressure [6]

|  | E21B 33/13 |
· · | Methods or devices for cementing, for plugging holes, crevices, or the like (dump bailers Fulltext... Hierarchy... Expanded...E21B 27/02; chemical compositions therefor Fulltext... Hierarchy... Expanded...C09K 8/00) [1,8]

|  | E21B 33/134 |
· · · | Bridging plugs

|  | E21B 33/136 |
· · · | Baskets, e.g. of umbrella type

|  | E21B 33/138 |
· · · | Plastering the borehole wall; Injecting into the formation

|  | E21B 33/14 |
· · · | for cementing casings into boreholes

|  | E21B 33/16 |
· · · · | using plugs for isolating cement charge; Plugs therefor

P:130 |  | E21B 34/00 |
Valve arrangements for boreholes or wells (in drilling fluid circulation systems Fulltext... Hierarchy... Expanded...E21B 21/10; blow-out preventers Fulltext... Hierarchy... Expanded...E21B 33/06; oil flow regulating apparatus Fulltext... Hierarchy... Expanded...E21B 43/12; valves in general Fulltext... Hierarchy... Expanded...F16K) [3]

|  | E21B 34/02 |
· | in well heads [3]

|  | E21B 34/04 |
· · | in underwater well heads [3]

|  | E21B 34/06 |
· | in wells [3]

|  | E21B 34/08 |
· · | responsive to flow or pressure of the fluid obtained (Fulltext... Hierarchy... Expanded...E21B 34/10 takes precedence) [3]

|  | E21B 34/10 |
· · | operated by control fluid supplied from outside the borehole (control means being outside the borehole Fulltext... Hierarchy... Expanded...E21B 34/16) [3]

|  | E21B 34/12 |
· · | operated by movement of casings or tubings [3]

|  | E21B 34/14 |
· · | operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools [3]

|  | E21B 34/16 |
· | Control means therefor being outside the borehole [3]

P:70 |  | E21B 35/00 |
Methods or apparatus for preventing or extinguishing fires (cutting or deforming pipes to control fluid flow Fulltext... Hierarchy... Expanded...E21B 29/08; controlling flow of fluid to or in wells Fulltext... Hierarchy... Expanded...E21B 43/12; fire fighting in general Fulltext... Hierarchy... Expanded...A62C, Fulltext... Hierarchy... Expanded...A62D)

P:10 |  | E21B 36/00 |
Heating, cooling, or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones (drilling by use of heat Fulltext... Hierarchy... Expanded...E21B 7/14; secondary recovery methods using heat Fulltext... Hierarchy... Expanded...E21B 43/24) [3]

|  | E21B 36/02 |
· | using burners [3]

|  | E21B 36/04 |
· | using electrical heaters [3]

P:110 |  | E21B 37/00 |
Methods or apparatus for cleaning boreholes or wells (Fulltext... Hierarchy... Expanded...E21B 21/00 takes precedence; cleaning pipes in general Fulltext... Hierarchy... Expanded...B08B 9/02)

|  | E21B 37/02 |
· | Scrapers specially adapted therefor

|  | E21B 37/04 |
· · | operated by fluid pressure, e.g. free-piston scrapers (operating other tools by fluid pressure Fulltext... Hierarchy... Expanded...E21B 23/08) [3]

|  | E21B 37/06 |
· | using chemical means for preventing or limiting the deposition of paraffins or like substances (chemical compositions therefor Fulltext... Hierarchy... Expanded...C09K 8/52) [3,8]

|  | E21B 37/08 |
· | cleaning in situ of down-hole filters, screens, or gravel packs (Fulltext... Hierarchy... Expanded...E21B 37/06 takes precedence) [3]

|  | E21B 37/10 |
· | Well swabs [3]

P:120 |  | E21B 40/00 |
Tubing catchers, automatically arresting the fall of oil-well tubing

P:240 |  | E21B 41/00 |
Equipment or details not covered by groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...E21B 15/00-E21B 40/00

|  | E21B 41/02 |
· | in situ inhibition of corrosion in boreholes or wells (dump bailers Fulltext... Hierarchy... Expanded...E21B 27/02; chemical compositions therefor Fulltext... Hierarchy... Expanded...C09K 8/54; inhibiting corrosion in general Fulltext... Hierarchy... Expanded...C23F) [3,6,8]

|  | E21B 41/04 |
· | Manipulators for underwater operations, e.g. temporarily connected to well heads (manipulators in general Fulltext... Hierarchy... Expanded...B25J) [3]

|  | E21B 41/06 |
· | Work chambers for underwater operations, e.g. temporarily connected to well heads (in general Fulltext... Hierarchy... Expanded...B63C 11/00) [3]

|  | E21B 41/08 |
· | Underwater guide bases, e.g. drilling templates; Levelling thereof [7]

|  | E21B 41/10 |
· | Guide posts, e.g. releasable; Attaching guide lines to underwater guide bases [7]

|  | E21B 43/00 |
Obtaining fluids from wells [3]

P:20 |  | 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 Fulltext... Hierarchy... Expanded...E03B; obtaining oil-bearing deposits or soluble or meltable materials by mining techniques Fulltext... Hierarchy... Expanded...E21C 41/00; pumps Fulltext... Hierarchy... Expanded...F04)

|  | E21B 43/01 |
· | specially adapted for obtaining from underwater installations (underwater well heads Fulltext... Hierarchy... Expanded...E21B 33/035)

|  | E21B 43/013 |
· · | Connecting a production flow line to an underwater well head [3]

|  | 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 Fulltext... Hierarchy... Expanded...E21B 43/36) [3]

|  | E21B 43/02 |
· | Subsoil filtering (Fulltext... Hierarchy... Expanded...E21B 43/11 takes precedence; chemical compositions for consolidating loose sand or the like around wells Fulltext... Hierarchy... Expanded...C09K 8/56) [1,8]

|  | E21B 43/04 |
· · | Gravelling of wells

|  | E21B 43/08 |
· · | Screens or liners

|  | E21B 43/10 |
· · | Setting of casings, screens or liners in wells (driving or forcing casings into boreholes, simultaneously drilling and casing boreholes Fulltext... Hierarchy... Expanded...E21B 7/20; setting of tools, packers or the like Fulltext... Hierarchy... Expanded...E21B 23/00; suspending casings in well heads Fulltext... Hierarchy... Expanded...E21B 33/04)

|  | E21B 43/11 |
· | Perforators; Permeators

|  | E21B 43/112 |
· · | Perforators with extendable perforating members, e.g. actuated by fluid means

|  | E21B 43/114 |
· · | Perforators using direct fluid action, e.g. abrasive jets

|  | E21B 43/116 |
· · | Gun or shaped-charge perforators

|  | E21B 43/117 |
· · · | Shaped-charge perforators (Fulltext... Hierarchy... Expanded...E21B 43/118 takes precedence)

|  | E21B 43/118 |
· · · | characterised by lowering in vertical position and subsequent tilting to operating position

|  | E21B 43/1185 |
· · · | Ignition systems [3]

|  | E21B 43/119 |
· · | Details, e.g. for locating perforating place or direction

|  | E21B 43/12 |
· | Methods or apparatus for controlling the flow of the obtained fluid to or in wells (Fulltext... Hierarchy... Expanded...E21B 43/25 takes precedence; valve arrangements Fulltext... Hierarchy... Expanded...E21B 34/00)

|  | E21B 43/14 |
· | Obtaining from a multiple-zone well

|  | E21B 43/16 |
· | Enhanced recovery methods for obtaining hydrocarbons (fracturing Fulltext... Hierarchy... Expanded...E21B 43/26; obtaining slurry Fulltext... Hierarchy... Expanded...E21B 43/29; reclamation of contaminated soil in situ Fulltext... Hierarchy... Expanded...B09C)

|  | E21B 43/17 |
· · | Interconnecting two or more wells by fracturing or otherwise attacking the formation (Fulltext... Hierarchy... Expanded...E21B 43/247 takes precedence) [3]

|  | E21B 43/18 |
· · | Repressuring or vacuum methods

|  | E21B 43/20 |
· · | Displacing by water

|  | E21B 43/22 |
· · | Use of chemicals or bacterial activity (Fulltext... Hierarchy... Expanded...E21B 43/27 takes precedence; chemical or bacterial compositions therefor Fulltext... Hierarchy... Expanded...C09K 8/58; chemical features in extracting oils from oil sands or shales Fulltext... Hierarchy... Expanded...C10G) [1,8]

|  | E21B 43/24 |
· · | using heat, e.g. steam injection (heating, cooling or insulating wells Fulltext... Hierarchy... Expanded...E21B 36/00)

|  | E21B 43/241 |
· · · | combined with solution mining of non-hydrocarbon minerals, e.g. solvent pyrolysis of oil shale [5]

|  | E21B 43/243 |
· · · | Combustion in situ [3]

|  | E21B 43/247 |
· · · · | in association with fracturing processes [3]

|  | E21B 43/248 |
· · · · · | using explosives [5]

|  | E21B 43/25 |
· | Methods for stimulating production (dump bailers Fulltext... Hierarchy... Expanded...E21B 27/02; vibration generating arrangements Fulltext... Hierarchy... Expanded...E21B 28/00; chemical compositions therefor Fulltext... Hierarchy... Expanded...C09K 8/60) [1,8]

|  | E21B 43/26 |
· · | by forming crevices or fractures

|  | E21B 43/263 |
· · · | using explosives [3]

|  | E21B 43/267 |
· · · | reinforcing fractures by propping [3]

|  | E21B 43/27 |
· · · | by use of eroding chemicals, e.g. acids

|  | E21B 43/28 |
· | Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent (Fulltext... Hierarchy... Expanded...E21B 43/241 takes precedence) [5]

|  | E21B 43/285 |
· | Melting minerals, e.g. sulfur (Fulltext... Hierarchy... Expanded...E21B 43/24 takes precedence; heating, cooling or insulating arrangements for wells Fulltext... Hierarchy... Expanded...E21B 36/00) [5]

|  | E21B 43/29 |
· | Obtaining a slurry of minerals, e.g. by using nozzles [5]

|  | E21B 43/295 |
· | Gasification of minerals, e.g. for producing mixtures of combustible gases (Fulltext... Hierarchy... Expanded...E21B 43/243 takes precedence) [5]

|  | E21B 43/30 |
· | Specific pattern of wells, e.g. optimizing the spacing of wells (production satellite stations Fulltext... Hierarchy... Expanded...E21B 43/017) [3]

|  | E21B 43/32 |
· | Preventing gas- or water-coning phenomena, i.e. the formation of a conical column of gas or water around wells [3]

|  | E21B 43/34 |
· | Arrangements for separating materials produced by the well (separating apparatus per se, see the relevant subclasses) [3]

|  | E21B 43/36 |
· · | Underwater separating arrangements (Fulltext... Hierarchy... Expanded...E21B 43/38 takes precedence) [3]

|  | E21B 43/38 |
· · | in the well [3]

|  | E21B 43/40 |
· · | Separation associated with re-injection of separated materials [3]

|  | E21B 44/00 |
Automatic control; Surveying or testing [3]

P:160 |  | 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 Fulltext... Hierarchy... Expanded...E21B 19/20; controlling pressure or flow of drilling fluid Fulltext... Hierarchy... Expanded...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 Fulltext... Hierarchy... Expanded...E21B 47/12) [3]

|  | E21B 44/02 |
· | Automatic control of the tool feed (Fulltext... Hierarchy... Expanded...E21B 44/10 takes precedence) [7]

|  | E21B 44/04 |
· · | in response to the torque of the drive [7]

|  | E21B 44/06 |
· · | in response to the flow or pressure of the motive fluid of the drive [7]

|  | E21B 44/08 |
· · | in response to the amplitude of the movement of the percussion tool, e.g. jump or recoil [7]

|  | E21B 44/10 |
· | Arrangements for automatic stopping when the tool is lifted from the working face [7]

|  | E21B 45/00 - E21B 49/00 |
Surveying or testing

P:170 |  | E21B 45/00 |
Measuring the drilling time or rate of penetration

P:30 |  | E21B 47/00 |
Survey of boreholes or wells (monitoring pressure or flow of drilling fluid Fulltext... Hierarchy... Expanded...E21B 21/08; geophysical logging Fulltext... Hierarchy... Expanded...G01V)

|  | E21B 47/01 |
· | Devices for supporting measuring instruments on a drill pipe, rod or wireline (setting or locking tools in boreholes or wells Fulltext... Hierarchy... Expanded...E21B 23/00); Protecting measuring instruments in boreholes against heat, shock, pressure or the like [6]

|  | E21B 47/02 |
· | Determining slope or direction (clinometers or direction meters Fulltext... Hierarchy... Expanded...G01C)

|  | E21B 47/022 |
· · | of the borehole

|  | E21B 47/024 |
· · | of devices in the borehole (Fulltext... Hierarchy... Expanded...E21B 47/022 takes precedence)

|  | E21B 47/026 |
· · | of penetrated ground layers (apparatus for obtaining oriented cores Fulltext... Hierarchy... Expanded...E21B 25/16; formation testing Fulltext... Hierarchy... Expanded...E21B 49/00)

|  | E21B 47/04 |
· | Measuring depth or liquid level (measuring liquid level in general Fulltext... Hierarchy... Expanded...G01F)

|  | E21B 47/06 |
· | Measuring temperature or pressure (measuring temperature in general Fulltext... Hierarchy... Expanded...G01K; measuring pressure in general Fulltext... Hierarchy... Expanded...G01L)

|  | E21B 47/08 |
· | Measuring diameter (measuring diameter in general Fulltext... Hierarchy... Expanded...G01B)

|  | E21B 47/09 |
· | Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes (measuring depth Fulltext... Hierarchy... Expanded...E21B 47/04; measuring diameter Fulltext... Hierarchy... Expanded...E21B 47/08) [3]

|  | E21B 47/10 |
· | Locating fluid leaks, intrusions, or movements

|  | E21B 47/12 |
· | Means for transmitting measuring-signals from the well to the surface, e.g. for logging while drilling (remote signalling in general Fulltext... Hierarchy... Expanded...G08)

|  | E21B 47/14 |
· · | using acoustic waves [6]

|  | E21B 47/16 |
· · · | through the drill string or casing [6]

|  | E21B 47/18 |
· · · | through the well fluid [6]

P:50 |  | 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 Fulltext... Hierarchy... Expanded...G01N 1/00)

|  | E21B 49/02 |
· | by mechanically taking samples of the soil (apparatus for obtaining undisturbed cores Fulltext... Hierarchy... Expanded...E21B 25/00; investigation of foundation soil in situ Fulltext... Hierarchy... Expanded...E02D 1/00)

|  | E21B 49/04 |
· · | using explosives in boreholes; using projectiles penetrating the wall [3]

|  | E21B 49/06 |
· · | using side-wall drilling tools or scrapers

|  | E21B 49/08 |
· | Obtaining fluid samples or testing fluids, in boreholes or wells [3]

|  | E21B 49/10 |
· · | using side-wall fluid samplers or testers [3]