Patent ID: 6059051
Filing Date: 2000-05-09
Classification: E21B

Abstract:
A drilling tool for forming a borehole in an earth formation, comprising:(a) a drill bit at an end of the drilling tool, said drill bit upon rotation forming a first portion of the borehole having a first size;(b) a cutting device uphole of the drill bit, said cutting device upon rotation forming a second portion of the borehole which is greater in size than the first portion;(c) a drilling motor carried by the drilling tool, said drilling motor rotating the drill bit and the cutting device when a fluid under pressure is passed through the drilling motor, thereby forming the first and second portions of the borehole;(d) a first stabilizer between the drill bit and the cutting device for providing lateral stability and drilling direction guidance to the drill bit; and(e) a second stabilizer uphole of the cutting device, said second stabilizer including at least one member adapted to extend radially from the tool to contact the borehole to provide radial stability to the drilling tool during drilling of the borehole.