Patent ID: 6633252
Filing Date: 2003-10-14
Classification: F41H,G01S,G01V

Abstract:
A plow steering system for directional drilling, comprising:a set of first through fourth pressure pads distributed around the outside surface of a steering plow for placement behind a directional drilling drill bit; an upward-looking radar antenna embedded in said first pressure pad; a downward-looking radar antenna embedded in said second pressure pad; a ground-penetrating radar transceiver connected to each of the upward-looking and downward-looking radar antennas, and providing for return signal attenuation and phase shift measurements, and for providing from said measurements real-time estimates of the distances transmitted radar signals traveled before being reflected back to a respective antenna; and a guidance control providing for steering of said directional drilling drill bit according to said real-time estimates, wherein said steering is provided by retracting and extending individual ones of said first through fourth pressure pads.