Patent ID: 6213229
Filing Date: 2001-04-10
Classification: E21B

Abstract:
A drilling assembly comprising:a downhole drilling motor having a top end and a bottom end, the top end being adapted for connection to a drill string, the motor having a rotatable longitudinal driven shaft connected to a longitudinal cylindrical mandrel on the bottom end of the motor, the mandrel having a transverse diameter and a distal end opposite the shaft, the distal end of the mandrel having an axial internally threaded mandrel box;a longitudinal cylindrical reaming stabilizer having a top end and a bottom end, the top end of the stabilizer being threadably connected to the internally threaded mandrel box, the stabilizer having longitudinal flutes and lands, the lands defining a transverse stabilizer diameter greater than the transverse diameter of the mandrel, the bottom end of the stabilizer having an axial internally threaded stabilizer box;a drill bit threadably received in the stabilizer box, the drill bit having a transverse diameter substantially the same as the transverse diameter of the stabilizer;wherein the stabilizer is sized so that the drill bit is longitudinally spaced apart from the distal end of the mandrel by the stabilizer by no more than about 16 inches.