Patent ID: 6290002
Filing Date: 2001-09-18
Classification: E21B

Abstract:
A drilling assembly for use in directional drilling, wherein the drilling assembly has a nominal drilling assembly gauge and wherein the drilling assembly comprises:(a) a drilling bit, wherein the drilling bit has a distal end which defines a distal end of the drilling assembly;(b) a near bit stabilizer located a first axial distance from the distal end of the drilling assembly, wherein the near bit stabilizer has a near bit stabilizer gauge and wherein the near bit stabilizer gauge is greater than the nominal drilling assembly gauge;(c) an adjustable gauge stabilizer located a second axial distance from the distal end of the drilling assembly, wherein the second axial distance is greater than the first axial distance, wherein the adjustable gauge stabilizer is adjustable between an extended gauge and a retracted gauge, and wherein the retracted gauge is less than the near bit stabilizer gauge;wherein the drilling bit is supported in the drilling assembly such that a bit drop angle is created between the near bit stabilizer and the drilling bit, wherein a stabilizer angle is created between the near bit stabilizer and the adjustable gauge stabilizer, wherein the combination of the bit drop angle and the stabilizer angle results in a net build angle of the drilling assembly when the adjustable gauge stabilizer is adjusted to the retracted gauge, and wherein the combination of the bit drop angle and the stabilizer angle results in a net drop angle of the drilling assembly when the adjustable gauge stabilizer is adjusted to the extended gauge.