Abstract: An apparatus and method for drilling a bore hole (B) along an underground arcuate path (P) between two surface locations (O,E). The bore hole (B) is drilled in one direction with a drill string (10) having a leading pipe section 12 with a drill bit (14) thereon. Drilling fluid is supplied to the drill bit (14) during the drilling operation. Upon completion of the initial bore hole (B), the hole (B) may be enlarged by a reamer (40). Then, a production conduit (38) is connected to the reamer (40) for being pulled by the drill string (10) through the enlarged bore hole (D). Cement is supplied through the drill string (10) for discharge at the reamer (40) into the bore hole (D) adjacent the leading end of the production conduit (38) and fills the annulus A between the conduit (38) and the inner peripheral surface of the enlarged bore hole (D). In one embodiment (FIG. 12), the drill string (10B) is encased in cement in the initial bore hole (B) and forms a casing for receiving a small diameter production cable.

Abstract: An apparatus and method for drilling and then installing a production conduit (46) within an enlarged bore hole (D) along an underground path (P) between two surface locations (C, D). Upon completion of a pilot bore hole (B), a reamer (48) enlarges the bore hold (B). The drill string (10) is returned to the exit opening (E) for connection to the production conduit (46) for pulling the conduit (46) within the enlarged opening (D). One embodiment (FIGS. 19-21) utilizes canted rollers (168) for supporting the production conduit (46) at the exit opening (E) and effecting rotation thereof as the production conduit (46) is fed into the enlarged diameter opening (D).

Abstract: An apparatus and method for drilling a pilot bore hole (B) along an underground arcuate path (P) between two surface locations (O, E). The pilot bore hole (B) is drilled in one direction with a drill string (10) having a leading pipe section (10A) of a reduced diameter to provide increased flexibility. Upon completion of the pilot bore hole (B), a reamer (48) connected to a product conduit (46) is connected to the drill string (10). Drill string (10) pulls the reamer (48) and product conduit (46) along the pilot bore hole (B) in an opposite direction for enlarging the bore hole (B) to receive the product conduit (46). A spud bit (34) has a flat or blunt leading end portion (34A) with a discharge opening (34D) therein to discharge high velocity drilling fluid into the formation at a location offset from the longitudinal axis of the drill string (10) to assist in guiding the drill string (10). An in-hole hydraulic motor (70) is provided in an embodiment (FIG.

Abstract: An apparatus and method for drilling a pilot bore hole (B) along an underground arcuate path (P) between two surface locations (O, E). The pilot bore hole (B) is drilled in one direction with a drill string (10) having a leading pipe section (10A) of a reduced diameter to provide increased flexibility. Upon completion of the pilot bore hole (B), a reamer (48) connected to a product conduit (46) is connected to the drill string (10). Drill string (10) pulls the reamer (48) and product conduit (46) along the pilot bore hole (B) in an opposite direction for enlarging the bore hole (B) to receive the product conduit (46). A spud bit (34) has a flat or blunt leading end portion (34A) with a discharge opening (34D) therein to discharge high velocity drilling fluid into the formation at a location offset from the longitudinal axis of the drill string (10) to assist in guiding the drill string (10). An in-hole hydraulic motor (70) is provided in an embodiment (FIG.