CPC Main Group
E21B 43/00 Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B)
Filing statistics
CPC E21B 43/00 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
16 direct subcodes
Child Classifications
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- E21B 43/01 specially adapted for obtaining from underwater installations
- E21B 43/02 Subsoil filtering
- E21B 43/11 Perforators; Permeators
- E21B 43/12 Methods or apparatus for controlling the flow of the obtained fluid to or in wells (E21B43/25 takes precedence; valve arrangements E21B34/00)
- E21B 43/14 Obtaining from a multiple-zone well
- E21B 43/16 Enhanced recovery methods for obtaining hydrocarbons
- E21B 43/25 Methods for stimulating production
- E21B 43/28 Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent (E21B43/241 takes precedence)
- E21B 43/285 Melting minerals, e.g. sulfur (E21B43/24 takes precedence)
- E21B 43/29 Obtaining a slurry of minerals, e.g. by using nozzles
- E21B 43/295 Gasification of minerals, e.g. for producing mixtures of combustible gases (E21B43/243 takes precedence)
- E21B 43/30 Specific pattern of wells, e.g. optimising the spacing of wells
- E21B 43/32 Preventing gas- or water-coning phenomena, i.e. the formation of a conical column of gas or water around wells
- E21B 43/34 Arrangements for separating materials produced by the well
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