Patent ID: 6629476
Filing Date: 2003-10-07
Classification: E21B

Abstract:
A method to fabricate a bi-center bit adapted to rotate about a pass-through axis â€œBâ€  or a rotational axis â€œAâ€  where the bi-center bit comprises a bit body having a proximal end and a distal end where the distal end defines a pilot bit section and an intermediate reamer section, where the pilot and reamer sections define a bit face including primary and secondary cutting blades and cutting elements disposed on said blades where each cutting element defines a cutting face, the method comprising the steps of:fabricating a cutter profile for the bit about the rotational axis â€œAâ€ ; identifying the pass-through axis â€œBâ€  of the bit; fabricating a cutter profile for the bit about the pass-through axis â€œBâ€ ; and situating selected ones of said cutting elements on the bit face of the pilot and reamer sections such that at least a portion of each cutting element is disposed about substantially all portions of said profiles when the bit is rotated about the rotational and pass-through axes.