CPC Subgroup
E21B 33/12 Packers; Plugs (used for cementing E21B33/134, E21B33/16)
Full Title
Sealing or packing boreholes or wells > in the borehole > Packers; Plugs (used for cementing E21B33/134, E21B33/16)
Filing statistics
CPC E21B 33/12 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
8 direct subcodes
Child Classifications
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- E21B 33/122 Multiple string packers
- E21B 33/124 Units with longitudinally-spaced plugs for isolating the intermediate space
- E21B 33/126 with fluid-pressure-operated elastic cup or skirt (E21B33/122, E21B33/124 take precedence)
- E21B 33/127 with inflatable sleeve (E21B33/122, E21B33/124 take precedence)
- E21B 33/128 with a member expanded radially by axial pressure (E21B33/122, E21B33/124 take precedence)
- E21B 33/129 with mechanical slips for hooking into the casing (E21B33/122, E21B33/124 take precedence)
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