DRILL PIPE TORQUE-REDUCTION AND PROTECTION APPARATUS
摘要
A torque-reduction and/or protection device for use in a drill string comprises a generally cylindrical body (10) including a mandrel portion (18) and a rotatable collar (20) mounted on the mandrel portion between first and second shoulders (22, 24), one of which is defined by a ring member (24) secured to said body after the collar has been located. A low friction bearing is provided between the collar and the mandrel including at least one of the following on the bearing surfaces of each of the collar and mandrel: low friction alloy coating; low friction ceramic coating; low friction alloy insert; low friction ceramic insert; magnetic elements. The collar has a low friction coating (30) on its outer surface comprising a composite coating having an inner layer of hard low friction material and an outer coating of relatively softer low friction material. The device may be incorporated into a sub but is preferably incorporated in a tool joint of a length of drill pipe.
申请公布号
WO0159249(A3)
申请公布日期
2002.01.31
申请号
WO2001GB00486
申请日期
2001.02.08
申请人
STABLE SERVICES LIMITED;SCHMIDT, KARL;STEWART, ARTHUR, DEACEY;CRAIG, MARK, WILLIAM
发明人
SCHMIDT, KARL;STEWART, ARTHUR, DEACEY;CRAIG, MARK, WILLIAM