دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

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.

v: 1. to unscrew one section of pipe from another section, especially drill pipe while it is being withdrawn from the wellbore. During this operation, the tongs are used to start the unscrewing operation. 2.to separate, as gas from a liquid or water from an emulsion.

unscrewing a joint of pipe of part of a BHA.

v: unscrewing the drill stem into single joints and placing them 00 the pipe rack. The operation takes place 00 completion of the well, or in changing from one size of pipe to another. See lay down pipe.

n: Put the singles which are unloaded from drill pipe stand on the pipe carrier.

n: a device attached to the catshaft of the drawworks that is used as a power source for unscrewing drill pipe;usually located opposite the drillers side of the drawworks. See cathead.

n: The self-releasing cathead installed in the cat shaft of drawworks.

n pi: tongs that are used to start unscrewing one section of pipe from another section, especially drill pipe coming out of the hole. Compare makeup tongs. See also tongs.

n: See tong.

Free Point analysis followed by downhole unscrewing of a pipe coupling above the stuck point.

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).