DIFF Subgroup
E21B 25/02 the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe
Introduced: January 1980
Full Title
Full titles differ between systems:
IPC:
Apparatus for obtaining or removing undisturbed cores, e.g. core barrels or core extractors > the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe
CPC:
Apparatus for obtaining or removing undisturbed cores, e.g. core barrels or core extractors (core bits E21B10/02) > the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe
IPC and CPC are identically structured here. All 1 subcodes exist in both systems.
IPC defines codes here since 1980.
Child Classifications
Navigate with arrow keys, Enter to open
- E21B 25/04 the core receiver having a core forming cutting edge or element, e.g. punch type core barrels 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