دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

abbr: circulated;used in drilling reports. circle wrench n: see wheel-type back-off wrench.

v: the procedure whereby one threaded piece (such as a pipe) is unscrewed from another.

v: To disconnect a string of pipe by unscrewing one threaded piece from another.

unscrewing a tool or equipment. In pipe recovery, back-off of a joint precedes recovery of the upper section in a well. Common in plug and abandonment or sidetrack operations.

n: To unscrew one threaded piece (as a section of pipe) from another

n: see washover backoff connector.

n: a section of pipe with lefthand threads on one end and conventional right-hand threads on the other. In setting a liner, a back-off joint is attached to it so that the drill pipe may be disengaged from the liner by conventional right-hand rotation.

n: The pipe sub whose one respect is left hand thread and the other one is right hand thread.

n: A kind of explosive package used for breakouting pack of dynamic. It is sent by cable to first thread above the sticking point. Pull the drill stem and rotate left the

n: see wheel-type back-off wrench.

n: a kind of fishing tool which can loosen the chafed pipe when unfreezing and back-off is invalid

n: a device used to unscrew rods when the pump is stuck or sanded up and the rods and tubing must be pulled together.

n: an explosive method utilizing Primacord. which is an instantaneous textilecovered fuse with a core of very high explosive. It is used to create an explosive jar inside stuck drill pipe or tubing so that the pipe may be backed off at the joint immediately above where it is stuck.

n: An explosive line which ,when detonated ,imparts concussion to pipe causing it to unscrew or back-off.Also called Prima-Cord.

one to four strands of explosive detonating cord suspended by wireline in a well and exploded to “rattle” the pipe and drop scale and debris from the sides of the pipe. Used frequently in back-off operations (unscrewing a pipe joint downhole).