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CPC Subgroup
E21B 19/08

Apparatus for feeding the rods or cables (E21B19/22 takes precedence; automatic feed E21B44/02); Apparatus for increasing or decreasing the pressure on the drilling tool; Apparatus for counterbalancing the weight of the rods

Full Title

Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables > Apparatus for feeding the rods or cables (E21B19/22 takes precedence; automatic feed E21B44/02); Apparatus for increasing or decreasing the pressure on the drilling tool; Apparatus for counterbalancing the weight of the rods

Filing statistics

CPC E21B 19/08 belongs to the parent subclass E21B, which recorded 241,108 patent applications worldwide between 2013 and 2023. Annual filings declined from 20,629 in 2013 to 18,982 in 2023 (-8%), peaking at 24,423 applications in 2016. The most active applicants in class E21 are HALLIBURTON ENERGY SERVICES GROUP (27,652 applications), SAUDI ARABIAN OIL COMPANY (7,755 applications) and PETROCHINA COMPANY (7,025 applications).

Source: EPO PATSTAT, worldwide filings

7 direct subcodes

Child Classifications

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  • E21B 19/081 Screw-and-nut feed mechanisms
  • E21B 19/083 Cam, rack or like feed mechanisms
  • E21B 19/084 with flexible drawing means, e.g. cables
  • E21B 19/086 with a fluid-actuated cylinder (E21B19/084, E21B19/087, E21B19/09 take precedence)
  • E21B 19/087 by means of a swinging arm
  • E21B 19/089 with a spring or an additional weight
  • E21B 19/09 specially adapted for drilling underwater formations from a floating support using heave compensators supporting the drill string

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