CPC Main Group
E21B 1/00 Percussion drilling
4 direct subcodes
Child Classifications
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- E21B 1/02 Surface drives for drop hammers , e.g. with a cable
- E21B 1/12 with a reciprocating impulse member (E21B1/02, E21B1/38 take precedence)
- E21B 1/36 Tool-carrier piston type, i.e. in which the tool is connected to an impulse member
- E21B 1/38 Hammer piston type, i.e. in which the tool bit or anvil is hit by an impulse member
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