Title:
【発明の名称】掘削ジャ-
Document Type and Number:
Japanese Patent JPH06102952
Kind Code:
B2
Abstract:
A drilling jar (100) includes a swivel (20) which allows the drilling jar to operate substantially independently of any right hand torque that becomes trapped in the drill string. The swivel (20) includes a bearing cage (9) that engages the polished stem (4) of the drilling jar to the jay stem (5) of the drilling jar. This bearing cage (9) holds a number of bearings (10) against the jay stem (5) and the polished stem (4). The swivel (20) allows the jay stem (5) to rotate substantially independently of the polished stem (4). The drilling jar may further include splines (8) formed onto the outer surface of the polished stem (4) for transmitting torque from the polished stem (4) to the barrel (1) of the drilling jar without simultaneously transmitting torque from the polished stem (4) to the jay stem (5). In addition, the drilling jar may include floating pistons (11,12) that are circumferentially engaged to the polished stem (4) and the washpipe (7) that effect the upper and lower seals on the drilling jar and allow the internal pressure inside the tool to be equalized with the internal and external pressures of the drill string.
Inventors:
Chuan, Sea, Ten
Lean, A, Chapel
John, Yi, Black Rose
Lee, Yi, McCamsea
Lean, A, Chapel
John, Yi, Black Rose
Lee, Yi, McCamsea
Application Number:
JP13781087A
Publication Date:
December 14, 1994
Filing Date:
June 02, 1987
Export Citation:
Assignee:
Daily, Petroleum, Services, Co-Polation
International Classes:
E21B7/04; E21B7/08; E21B31/107; (IPC1-7): E21B31/107
Attorney, Agent or Firm:
Kazuo Sato (2 outside)