CPC Main Group
E21B 7/00 Special methods or apparatus for drilling
Filing statistics
CPC E21B 7/00 belongs to the parent subclass E21B, which recorded 241,108 patent applications worldwide between 2013 and 2023. Annual filings declined from 20,629 in 2013 to 18,982 in 2023 (-8%), peaking at 24,423 applications in 2016. The most active applicants in class E21 are HALLIBURTON ENERGY SERVICES GROUP (27,652 applications), SAUDI ARABIAN OIL COMPANY (7,755 applications) and PETROCHINA COMPANY (7,025 applications).
Source: EPO PATSTAT, worldwide filings
15 direct subcodes
Child Classifications
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- E21B 7/02 Drilling rigs characterised by means for land transport , e.g. skid mounting or wheel mounting
- E21B 7/04 Directional drilling
- E21B 7/12 Underwater drilling (using heave compensators E21B19/09)
- E21B 7/14 Drilling by use of heat, e.g. flame drilling
- E21B 7/16 Applying separate balls or pellets by the pressure of the drill, so-called shot-drilling
- E21B 7/18 Drilling by liquid or gas jets, with or without entrained pellets (E21B7/14 takes precedence)
- E21B 7/20 Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes
- E21B 7/24 Drilling using vibrating or oscillating means, e.g. out-of-balance masses (percussion drilling E21B1/00)
- E21B 7/26 Drilling without earth removal, e.g. with self-propelled burrowing devices (E21B7/30 takes precedence)
- E21B 7/28 Enlarging drilled holes, e.g. by counterboring
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