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IPC Subgroup
E21B 47/09

Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes

Introduced: January 1980

Last revised: January 2012

Full Title

Survey of boreholes or wells > Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes

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

3 direct subcodes

Child Classifications

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  • E21B 47/092 by detecting magnetic anomalies
  • E21B 47/095 by detecting acoustic anomalies, e.g. using mud-pressure pulses
  • E21B 47/098 using impression packers, e.g. to detect recesses or perforations

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