Making and breaking of couplings between pipe sections in a drilling rig

Abstract

For making of breaking a coupling between a pipe section ( ) and a pipe string ( ) projecting from a rotary drilling rig into a bore in the lithosphere, the pipe section ( ) is rotated relative to the pipe string ( ) by applying a torque up to a make-up or breaking torque. Exertion of said torque generates a reactive torque in an opposite sense of rotation. Rotation induced by a motor ( ) is transferred to the pipe string ( ) so that said pipe string ( ) is rotated as well. The reactive torque is transferred to the pipe string ( ) along a path bypassing the motor ( ). Thus, the make-up or breaking torque can be exerted without requiring a substantial change of the torque exerted to rotate the pipe string ( ) at a constant rotational velocity in order to avoid changes of the rotational velocity of the pipe string ( ). A pipe coupling device and a pipe handler for carrying out this method are described as well.