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DIFF Subgroup
E21B 33/035

specially adapted for underwater installations (E21B33/043, E21B33/064, E21B33/076 take precedence)

Introduced: September 1968

Title

Titles differ between systems:

IPC: specially adapted for underwater installations

CPC: specially adapted for underwater installations (E21B33/043, E21B33/064, E21B33/076 take precedence)

Full Title

Full titles differ between systems:

IPC:

Sealing or packing boreholes or wells > Surface sealing or packing > Well heads; Setting-up thereof > specially adapted for underwater installations

CPC:

Sealing or packing boreholes or wells > Surface sealing or packing > Well heads; Setting-up thereof > specially adapted for underwater installations (E21B33/043, E21B33/064, E21B33/076 take precedence)

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

3 codes are CPC-only extensions.

IPC defines codes here since 1980.

Child Classifications

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  • E21B 33/0353 CPC only CPC only
  • E21B 33/0355 CPC only CPC only
  • E21B 33/0387 CPC only CPC only

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