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DIFF Subgroup
E21B 43/24

using heat, e.g. steam injection

Introduced: September 1968

Full Title

Full titles differ between systems:

IPC:

Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells > Enhanced recovery methods for obtaining hydrocarbons > using heat, e.g. steam injection

CPC:

Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B) > Enhanced recovery methods for obtaining hydrocarbons > using heat, e.g. steam injection

CPC subdivides this area 3x more granularly than IPC with 4 additional codes.

4 codes are CPC-only extensions.

1 shared codes have differing titles between IPC and CPC.

IPC defines codes here since 1980.

Child Classifications

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  • E21B 43/2401 CPC only CPC only
  • E21B 43/2403 CPC only CPC only
  • E21B 43/2405 CPC only CPC only
  • E21B 43/241 combined with solution mining of non-hydrocarbon minerals, e.g. solvent pyrolysis of oil shale since 1990 IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class E21,2013–2023, worldwide · Source: EPO PATSTAT

  1. HALLIBURTON ENERGY SERVICES GROUP US 26,607
  2. PETROCHINA COMPANY 14,382
  3. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 10,137
  4. CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 6,517
  5. BAKER HUGHES US 6,269
  6. SCHLUMBERGER TECHNOLOGY US 5,929
  7. SAUDI ARABIAN OIL COMPANY SA 5,880
  8. SOUTHWEST PETROLEUM UNIVERSITY 4,477
  9. CHINA UNIVERSITY OF MINING AND TECHNOLOGY 4,357
  10. SCHLUMBERGER TECHNOLOGY NL 4,219

Top Applicants (CPC)

Class E21,2013–2023, worldwide · Source: EPO PATSTAT

  1. HALLIBURTON ENERGY SERVICES GROUP US 27,652
  2. SAUDI ARABIAN OIL COMPANY SA 7,755
  3. PETROCHINA COMPANY 7,025
  4. BAKER HUGHES US 6,589
  5. SCHLUMBERGER TECHNOLOGY US 6,151
  6. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 4,443
  7. SCHLUMBERGER TECHNOLOGY NL 4,255
  8. CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 3,991
  9. SERVICES PETROLIERS SCHLUMBERGER FR 3,300
  10. SCHLUMBERGER CANADA CA 3,086