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DIFF Subgroup
E21B 21/015

Means engaging the bore entrance, e.g. hoods for collecting dust

Introduced: January 2000

Full Title

Full titles differ between systems:

IPC:

Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor > Arrangements for handling drilling fluids or cuttings outside the borehole, e.g. mud boxes > Means engaging the bore entrance, e.g. hoods for collecting dust

CPC:

Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor (freeing objects stuck in boreholes by flushing E21B31/03) > Arrangements for handling drilling fluids or cuttings outside the borehole, e.g. mud boxes > Means engaging the bore entrance, e.g. hoods for collecting dust

No child classifications to compare. This is a leaf node in both 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