Abstract: A flexible drill pipe adapted for connection in a drill string, having sufficient wall thickness in order to withstand forces imposed by drilling a well. The flexible pipe has a plurality of cuts defining interlocking teeth and recesses on axially adjacent segments of the pipe, the teeth in one segment being positioned in the recesses of, and interlocking with the teeth of, the adjacent segment. Each of the teeth includes a generally semicircular crown section, two essentially flat shoulders and a tapered base portion, with the curved, tapered sides of circumferentially adjacent bases forming the semicircular recesses for receiving the crowns of axially adjacent interlocking teeth.

Abstract: A rotary drag drill bit is seen wherein cutter bodies are rotatively connected to a main body structure at a fully offset position. The fully offset position is defined by a rotational axis of each cutter body, a longitudinal axis of the drill bit and end support points or positions of the cutter bodies. The rotational axes of the cutter bodies are perpendicular to the longitudinal axis of the drill bit. The end supports of the cutter body are each equal distance from any point on the longitudinal axis of the drill bit. The cutter bodies of essentially ellipsoidal configuration, being slightly thicker at a mid-portion thereof. Cutting elements are connected to flutes projecting above an outer surface of each cutter body. In a primary rotational direction of the drill string and drill bit, the rows abrade the bottom and side walls of a well bore as the cutter body attacks the earth formation as the drill bit is rotated.

Abstract: A shock absorbing tool is provided for connection to a drill column. The drill column includes a drill bit and is positioned in a bore formed in the earth. The shock absorbing tool is an integral, resilient cylindrical member having a number of open sections formed in the cylindrical member. Pairs of open sections are interconnected by slots. Pairs of open sections are longitudinally spaced along the periphery of the cylindrical member. The longitudinal distance between pairs of open sections and the circumferential distance between open sections of each pair of open sections vary. Upon application of dynamic axial and torsional loads to the drill column, the shock absorbing tool absorbs these loads through deflection of the resilient tool such that the slots close and the stress produced by the dynamic loading is carried about the periphery of the open sections.

Abstract: A drill rig for drilling a hole in the ground including a mast, having a longitudinal slide means at one face thereof, adapted to be set upright with the slide means facing, and being at a selected spacing from and parallel to the axis of a drill hole to be drilled with the rig; a slide frame mounted upon the mast slide means and lifter-pulldown means in the mast to move the slide frame along the longitudinal slide means; a lateral shifting means on the slide frame shiftable towards and away from the slide frame in the direction of the drill hole; a drill carrier attached to the shifting means to be shifted to a first position against the slide frame and to a second position outwardly therefrom; and a drill mechanism means including a drill pipe means mounted upon the drill carrier to effect drilling by a drill pipe means, with the drill pipe means being aligned with the drill hole axis when the drill carrier is at one of said positions.

Abstract: Multiple wall drill pipe adapted for use in a drill pipe string comprising an outer pipe member; an inner pipe member disposed within the outer pipe member; and means for releasably connecting the inner pipe member and the outer pipe member in fixed axial relationship under force loads applied in use during a drilling operation while enabling relative rotary movement between the inner pipe member and the outer pipe member during a rotary drilling operation to relieve torsional stress thereon, and for permitting the removal of the inner pipe member from the outer pipe member by relative axial displacement therebetween caused by application to the inner pipe member of only an axially directed force load in excess of the axially directed force loads applied to the inner pipe member in use during a normal drilling operation.

Abstract: Multiple wall drill pipe adapted for use in a drill pipe string comprising an outer pipe member; an inner pipe member disposed within the outer pipe member; and means for releasably connecting the inner pipe member and the outer pipe member in fixed axial relationship under force loads applied in use during a drilling operation while enabling relative rotary movement between the inner pipe member and the outer pipe member during a rotary drilling operation to relieve torsional stress thereon, and for permitting the removal of the inner pipe member from the outer pipe member by relative axial displacement therebetween caused by application to the inner pipe member of only an axially directed force load in excess of the axially directed force loads applied to the inner pipe member in use during a normal drilling operation.

Abstract: The present invention provides a means for mounting the inner pipe within the outer pipe of a double-walled pipe used in reverse-circulation drilling so that torques imparted to the outer pipe will not be imparted to the inner pipe, in order to avoid failure of the inner pipe. The inner pipe has a bushing slidably received thereon at each end, the bushing being affixed, as by a plurality of welded circumferentially spaced ribs, to the inner wall of the outer pipe so that the inner pipe is free to rotate relative to the outer pipe. An annular locating sleeve is received on and welded to the inner pipe adjacent each end of each bushing so that axial, or longitudinal movement of the inner pipe relative to the outer pipe is restrained. Since the inner pipe is free to rotate it will not be affected by excessive torque applied to the outer pipe and, in fact, the double-walled pipe can be given a higher torque rating than it would merit if the inner pipe were non-rotatably fixed to the outer pipe.