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CPC Subgroup
E21C 41/32

Reclamation of surface-mined areas (machines or methods for treating or working soil for agricultural purposes A01B77/00, A01B79/00; machines for back-filling E02F5/22)

Full Title

Methods of underground or surface mining (E21C45/00 takes precedence); Layouts therefor (for peat E21C49/00) > Reclamation of surface-mined areas (machines or methods for treating or working soil for agricultural purposes A01B77/00, A01B79/00; machines for back-filling E02F5/22)

Top Applicants

Top 10 applicants by patent filingsfor 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