Method of using a drill string tool

摘要

A method of operating a drill string tool for use in a wellbore formed in an earth formation is provided. T he method comprises rotating an upper drill string part while a rotation transfer assembly transfers the rotation of a first element to a second element so as to rotate a lower drill string part in order to drill a section of a wellbore, inducing a controller to disengage the rotation transfer assembly so as to allow the first element to rotate relative to the second element by virtue of bearings, and rotating the upper drill string part about its longitudinal axis while the lower drill string part remains substantially stationary.