Patent ID: 7334649
Filing Date: 2008-02-26
Classification: E21B

Abstract:
1. A method of drilling a bore hole utilizing a bottom hole assembly including a downhole motor having an upper power section with a power section central axis and a lower central axis, the bottom hole assembly further including a bit rotatable by the motor and having a bit face defining a bit cutting diameter greater than an outer diameter of a casing string run in the well with the bottom hole assembly, the method comprising: securing a gauge section below the bit, the gauge section having a substantially uniform diameter rotating bearing surface thereon while rotating along an axial length of at least about 60% of a pilot diameter, the bit diameter being less than about 122% of the casing string outer diameter; providing the pilot bit secured to and below the gauge section; and rotating the bit, the gauge section and the pilot bit by pumping fluid through the downhole motor to drill the borehole.