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IPC Subgroup
E21B 7/12

Underwater drilling

Introduced: September 1968

Last revised: January 2006

Full Title

Special methods or apparatus for drilling > Underwater drilling

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

Underwater drilling using heave compensators

Related Keywords

underwater DRILLINGSUBAQUEOUS deep drillingdeep-drilling UNDERWATER

4 direct subcodes

Child Classifications

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  • E21B 7/124 with underwater tool drive prime mover, e.g. portable drilling rigs for use on underwater floors
  • E21B 7/128 from floating support with independent underwater anchored guide base
  • E21B 7/132 from underwater buoyant support
  • E21B 7/136 from non-buoyant support

Top Applicants

Top 10 applicants by patent filingsfor 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