Patent ID: 7562725

Claim:
A drilling system for drilling a sub surface well bore having a surface end and a bottom end comprising: a drill string configured to extend from said surface end to a housing, said housing having an exterior surface and a distal end, said housing containing a mud motor in fluid communication with said surface via said drill string, whereby said mud motor may be operated with fluid pumped from said surface; a pilot bit extending from said distal end of said housing, said pilot bit in mechanical communication with said mud motor, whereby operation of said mud motor will power said pilot bit; and a reamer, comprising a bi-center bit and extending from the exterior surface of said housing, whereby rotation of said housing will rotate said reamer, wherein said reamer is mounted on a rotatable section of said housing, wherein said rotatable section of said housing is connected to said mud motor, whereby said mud motor is configured to rotate said reamer and said pilot bit, and wherein said housing and said reamer are configured to be rotated by rotating said drill string from said surface end of said well bore; and wherein said pilot bit is configured to rotate at a rate at least about three times the rate of rotation of said reamer.