IPC Main Group
E21B 43/00 Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
Introduced: September 1968
Last revised: January 2006
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
Additional Content
Installations or methods for obtaining, collecting or distributing water
Related Keywords
drilling for OIL(S)obtaining OIL(S) from deep wellsobtaining WATER from deep wells
14 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
- 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
- E21B 43/285 Melting minerals, e.g. sulfur
- 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
- E21B 43/3 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 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