CPC Subclass Not Allocatable
E21B EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
Description
E21B encompasses drilling techniques, equipment, and systems for accessing subsurface resources including oil, natural gas, water, and mineral deposits. This subclass covers drilling apparatus (rigs, bits, pipe strings), well construction methods, borehole management, and extraction technologies for both solid minerals (ores, salts) and fluids. Related technologies include mud systems, pressure control, wellbore stabilization, and completion equipment used throughout the drilling and production lifecycle.
31 direct subcodes
Child Classifications
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- E21B 1/00 Percussion drilling
- E21B 10/00 Drill bits (specially adapted for deflecting the direction of boring ; with means for collecting substances E21B27/00)
- E21B 11/00 Other drilling tools
- E21B 12/00 Accessories for drilling tools
- E21B 15/00 Supports for the drilling machine, e.g. derricks or masts
- E21B 17/00 Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Casings; Tubings
- 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
- 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 E21B31/03)
- E21B 2200/00 Special features related to earth drilling for obtaining oil, gas or water
- 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 E21B43/10)
- E21B 25/00 Apparatus for obtaining or removing undisturbed cores, e.g. core barrels or core extractors (core bits E21B10/02)
- 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
- E21B 28/00 Vibration generating arrangements for boreholes or wells, e.g. for stimulating production ( for transmitting measuring-signals E21B47/14; for geophysical measurements G01V1/02)
- 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; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
- E21B 3/00 Rotary drilling
- E21B 31/00 Fishing for or freeing objects in boreholes or wells
- E21B 33/00 Sealing or packing boreholes or wells
- E21B 34/00 Valve arrangements for boreholes or wells
- E21B 35/00 Methods or apparatus for preventing or extinguishing fires
- E21B 36/00 Heating, cooling or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones
Top Applicants
Top 10 applicants by patent filingsfor class E21, 2013–2023, worldwide · Source: EPO PATSTAT
- HALLIBURTON ENERGY SERVICES GROUP US 27,652
- SAUDI ARABIAN OIL COMPANY SA 7,755
- PETROCHINA COMPANY 7,025
- BAKER HUGHES US 6,589
- SCHLUMBERGER TECHNOLOGY US 6,151
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 4,443
- SCHLUMBERGER TECHNOLOGY NL 4,255
- CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 3,991
- SERVICES PETROLIERS SCHLUMBERGER FR 3,300
- SCHLUMBERGER CANADA CA 3,086