Abstract: A device for handling well pipe includes a mandrel including an upper end, a lower end and a long axis extending between through the upper end and the lower end. The mandrel secures to a top drive of a drilling rig. A threaded collar is located on an outer surface of the mandrel to loosely engage threads of a well pipe. An annular force generating assembly is carried on the mandrel and positioned between the upper end and the threaded collar. The force generating assembly applies a load to an upper end of the well pipe along the long axis, enabling torque to be transmitted between the threaded collar and the well pipe. The force generating assembly may be cams or a hydraulic piston.

Abstract: A system (10) for generating high pressure pulses has a source (12, 16) of a pressurized working fluid (14). The working fluid is supplied to two conduits (22,24). A valve (26) has an input connected to each of the conduits (22, 24). The valve has a valve member (29) that is movable between two positions. In one position the valve member allows working fluid to flow from the first conduit (22) to an outlet and blocks the second conduit (24). In the other position the valve member allows working fluid to flow from the first conduit (22) to the outlet and blocks the first conduit (22). Flow of the working fluid causes the valve member to reciprocate and thereby generate water hammers in conduits (22) and (24). Energy from the water hammers may be harnessed for various applications.