CPC Main Group Additional Only
E21B 2200/00 Special features related to earth drilling for obtaining oil, gas or water
10 direct subcodes
Child Classifications
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- E21B 2200/01 Sealings characterised by their shape
- E21B 2200/02 Down-hole chokes or valves for variably regulating fluid flow
- E21B 2200/03 Valves operated by gear mechanisms, e.g. rack and pinion mechanisms
- E21B 2200/04 Ball valves
- E21B 2200/05 Flapper valves
- E21B 2200/06 Sleeve valves
- E21B 2200/08 Down-hole devices using materials which decompose under well-bore conditions
- E21B 2200/09 Detecting, eliminating, preventing liquid slugs in production pipes
- E21B 2200/20 Computer models or simulations, e.g. for reservoirs under production, drill bits
- E21B 2200/22 Fuzzy logic, artificial intelligence, neural networks or the like
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