Patent ID: 7044240

Claim:
An assembly for deployment in a well bore, comprising: a drill string; a downhole drill motor carried at a lower end of the drill string; a rotary abrasive device coupled to the drill motor for rotation relative to the drill string in response to drilling fluid being pumped down the drill string; a tubular first module; a tubular second module partially disposed within the the first module; one of the modules being connected to the drill string and the other of the modules being connected to the drill motor; a passage through the modules to transmit drilling fluid to the drill motor; a helical interface between the first and second modules, so that rotation of one of the modules relative to the other due to changes in counter torque on the drill motor causes the modules to teleseopingly move relative to each other between contracted and extended positions; and a spring member mounted between the first and second modules for urging the modules towards the extended position.