Rotary drill bit compensating for changes in hardness of geological formations

摘要

A long lasting rotary drill bit for drilling a hole into variable hardness geological formations that has a self-actuating mechanism responsive to the hardness of the geological formation to minimize the time necessary to drill a borehole. A long lasting rotary drill bit for drilling a hole into variable hardness geological formations that has a mechanism controllable from the surface of the earth to change the mechanical configuration of the bit to minimize the time necessary to drill a borehole. A monolithic long lasting rotary drill bit for drilling a hole into a geological formation having hardened rods composed of hard material such as tungsten carbide that are cast into a relatively soft steel matrix material to make a rotary drill bit that compensates for wear on the bottom of the drill bit and that also compensates for lateral wear of the drill bit using passive, self-actuating mechanisms, triggered by bit wear to drill relatively constant diameter holes.