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)
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