Patent ID: 6394198
Filing Date: 2002-05-28
Classification: E21B

Abstract:
A frictional damper for a downhole tool, comprising:a. a downhole drilling tool having a damper portion adapted to receive a plurality of damper inserts; b. the damper inserts comprising of a hard metal body adapted for installation into the drilling tool and having a rounded working surface; c. the rounded working surface of the damper inserts being bonded to a layer of superhard material at high pressure and high temperature; and d. the damper inserts being arrayed about the tool body so as to describe a circumference larger than the desired gauge of a borehole, so that their working surface is constantly forced against the walls of the borehole, producing frictional damping by plastically deforming the formation, and producing a constant torsional load on the downhole tools and preventing rapid torsional unloading of the downhole tools, and thereby absorbing the axial and radial vibrations of the downhole tool.