DIFF Main Group
E21B 4/00 Drives for drilling, used in the borehole
Introduced: January 1980
Of 8 combined children, 6 exist in both systems.
2 codes are CPC-only extensions.
4 shared codes have differing titles between IPC and CPC.
IPC defines codes here since 1980.
Child Classifications
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- E21B 4/06 Down-hole impacting means, e.g. hammers (boring rams E21B11/02) since 1980 IPC+CPC Available in IPC and CPC
- E21B 4/16 Plural down-hole drives, e.g. for combined percussion and rotary drilling (E21B4/10 takes precedence); Drives for multi-bit drilling units since 1980 IPC+CPC Available in IPC and CPC
- E21B 4/20 combined with surface drive (E21B4/10 takes precedence) since 1980 IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Class E21,2013–2023, worldwide · Source: EPO PATSTAT
- HALLIBURTON ENERGY SERVICES GROUP US 26,607
- PETROCHINA COMPANY 14,382
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 10,137
- CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 6,517
- BAKER HUGHES US 6,269
- SCHLUMBERGER TECHNOLOGY US 5,929
- SAUDI ARABIAN OIL COMPANY SA 5,880
- SOUTHWEST PETROLEUM UNIVERSITY 4,477
- CHINA UNIVERSITY OF MINING AND TECHNOLOGY 4,357
- SCHLUMBERGER TECHNOLOGY NL 4,219
Top Applicants (CPC)
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