Rotary drag bit with pdc gauge bearing pads

摘要

In a rotary drag-type drill bit, or other downhole component used in subsurface drilling, bearing pads (16) which engage the surface of the earthen formation of the borehole carry wear-resistant bearing inserts (20) received in sockets in the bearing pad. Each bearing insert includes a preform element (21) of the kind normally used as cutting elements in drag-type drill bits, and having a front facing table (23) of polycrystalline diamond bonded to a less hard substrate (24). The preform element is orientated so that its front diamond surface is tangential to the surface of the bearing pad, or at a slight angle thereto, so as to provide a highly wear-resistant, but non-aggressive bearing insert. The preform element may be bonded to or partly embedded in a carrier (22) which is received within the socket. The element or carrier may be formed with spaced longitudinal ribs (23) to allow it to be force-fitted into the socket, or the element or carrier may be secured within a hollow sleeve which is formed with such ribs.