Abstract: A rack for supporting drilling tubulars such as drill pipe, collars and the like includes a base and a rail. The rail is coupled to the base by means of two columns, each of which is provided with threads such that the tilt angle of the rail with respect to the base can be adjusted to provide gravity feeding of drilling tubulars to either end of the rail. The rail is provided with two pivotably connected stop plates which move in opposition. The stop plates are controlled by means of an air cylinder to allow only one drilling tubular at a time from those stored on the rack to roll off the end of the rail. Furthermore, both stop plates can be retracted below the level of the rail so as not to interfere with the movement of tubulars onto the rack. The combination of the tiltable rail and the two stop plates provides a rack which can be used to control movement of drilling tubulars on to and off of the rack with a minimum of manpower requirements.

Abstract: A self-locking and unlocking elevator for use with drill pipe is disclosed which, in a specific embodiment, includes a pair of jaws, each shaped to support a length of pipe; and central and upper linkage assemblies, for opening and closing the jaws about a section of drill pipe. The invention also includes a ratchet mechanism for locking the jaws open to receive or release a length of pipe, or to allow changing the clamping surfaces to accommodate different sizes of pipe; and for unlocking the jaws to allow closure over and clamping of a length of pipe.

Abstract: A self locking and unlocking elevator for use with drill pipe is disclosed which, in a specific embodiment, includes a cam body which defines two symmetrically positioned cam surfaces. Each of these cam surfaces serves to support the upper end of a respective jaw, the lower end of which is shaped to clamp and hold the box end of a length of drill pipe. A collar is disposed around the jaws and is mechanically interlocked with the jaws such that both the collar and the jaws are suspended from the cam body. A plate is positioned below the collar above the box end of a clamped length of drill pipe and is secured to the cam body so as to move between a lower position in which the collar and jaws hang from the cam body, and an upper position in which the jaws are supported via the collar and the plate by the box end of the clamped drill pipe.

Abstract: A downhole hammer drill for use with a dual concentric tube drill pipe string is characterized by the use of pressurized air from the annular passageway of the pipe string to operate the hammer. The exhaust air from the hammer is conducted to the periphery of the bit face of the hammer drill, across the bit face, and then through one or more openings in the central portion of the bit face. The exhaust air with entrained cuttings and hole water is then channeled through the drill and into the central passageway of the pipe string, through which it is removed from the drilling area. In a preferred embodiment an injection sub is provided in the drill string uphole of the drill and a drill body which substantially fills the bore annulus is used to throttle the flow of water down the borehole annulus to the bit face. In this embodiment a head of water is maintained in the borehole annulus and this water cascades down around the hammer drill to prevent cuttings and fines from moving up the bore annulus.

Abstract: A clamp for drilling tubulars such as drill pipes includes a jaw which defines a cylindrical recess. A cylindrical insert is rotatably mounted within the recess. This insert defines a cylindrically symmetrical toothed surface positioned to grip and frictionally engage the clamped tubular, and a cylindrically convex positioning surface configured to cooperate with the cylindrical recess to hold the insert in place in the jaw. The insert is mounted in the jaw so as to rotate freely within a selected range of rotational positions in order to allow the insert to orient itself as necessary to maximize the area of contact between the insert and the clamped tubular over a range of tubular diameters. The insert is reversible in the recess so as to allow the insert to be positioned in the jaw as necessary to maximize frictional engagement with the clamped tubular in a selected direction of rotation.

Abstract: An improved boom for a drill rig is described which includes two rotatably mounted clamps which are rotatable between a side loading position, to facilitate loading and unloading in the horizontal position, and a central position, in which a clamped tubular is aligned with the drilling axis when the boom is in the vertical position. An automatic hydraulic sequencing circuit is provided to automatically rotate the clamps into the side loading position whenever the boom is pivoted with a down-hole tubular positioned in the clamp. In this position, the clamped tubular is aligned with a safety plate mounted on the boom to prevent a clamped tubular from slipping from the clamps. A safety frame is formed between the tower of the drill rig and the vertical boom by a slidable bolt mounted on the tower and an annular receiving member mounted on the boom to receive the end of the bolt. This boom also includes an improved pivoting linkage which facilitates the transport of the rig.

Abstract: A drilling ramp for a mobile drilling rig of the type having a wheeled vehicle and a mast substructure, wherein the substructure includes four legs, two of which serve to mount power hydraulic jacks and two of which serve to mount leg locating sockets. The ramp includes a substantially planar foundation structure adapted to support the drilling rig. Longitudinal guide bars and transverse chocks are mounted on the foundation structure to guide and position wheels of the drilling rig. Two jack locating members are mounted on the foundation structure, each of which defines a respective socket sized and positioned to interlock with respective ones of the two jacks included in the substructure. In addition, two manually operated jack screws are mounted on the foundation structure in alignment with the sockets on the rear legs of the substructure. Once the jacks have been engaged in the sockets of the ramp, the jack screws can be raised in order to provide support for the rear legs of the substructure.

Abstract: A drill rig having a drill rig mast and a transfer arm is described. The clamps of the transfer arm are resiliently mounted to the transfer arm so as to provide limited axial movement of the clamps and thereby of a clamped down hole tubular. This resilient support for the down hole tubular serves to reduce damage to the threaded ends of the tubular during tubular handling operations. In addition, the clamps of the transfer arm are provided with resilient clamping surfaces which serve to engage the clamped tubular frictionally, without gouging or deeply scratching the surface thereof. A pair of automatic, self-centering, hydraulic tongs is provided for making up and breaking out threaded connections of tubulars having various diameters without manual adjustment of the tongs.

Abstract: A self-centering clamp for drilling tubulars includes first and second transverse guide rods. Two opposed clamping jaws are guided along the first guide rod. These jaws are positioned by two opposed rocker arms, each of which is mounted to a cross brace which slides along the second guide rod. The rocker arms are symmetrically positioned by a link mechanism which also slides along the second guide rod and by a hydraulic cylinder coupled between the two rocker arms. The entire clamp is supported in a frame onto which is mounted the two guide rods. The frame is pivotably mounted to a pipe boom so as to rotate about an axis parallel to the clamped pipe and transverse to the first and second guide rods. In a second embodiment the guide rods are replaced with a plate having guide slots.

Abstract: A top head drive unit for an earth boring apparatus including a derrick comprises a support member guided along the derrick. The support member includes a pair of spherical roller bearings which support a shaft adapted for connection to a drill string. These roller bearings accommodate a selected degree of movement in the axis of rotation of the shaft. The shaft extends up above the support member, and a rotary drive unit is mounted to the shaft immediately above the support member. Precision roller bearings are used to align the drive unit precisely on the shaft such that the drive unit follows the movement of the shaft as it rotates in the spherical roller bearings of the support member and a torque arm is mounted between the support member and the rotary drive unit to prevent rotation of the rotary drive unit with respect to the support member.

Abstract: A self centering clamp for down-hole tubulars includes first and second opposed clamping members guided along a clamping axis by first and second guide channels defined by a frame. Each clamping member defines a hydraulic cylinder in which is disposed a piston which is rigidly mounted to the frame. A rack is coupled to move with each of the clamping members. These racks are interconnected via a pinion gear which meshes with both racks so that the two clamping members move in a counterdirectional manner and remain equidistant from a central point on the clamping axis. In this way the clamp centers down-hole tubulars of various diameters about the same line, perpendicular to the clamping axis.

Abstract: A skirted crossover sub for joining an air hammer to a string of dual concentric drill pipe is characterized by passageways for directing air from the pipe string annulus to operate the hammer and for directing exhaust air and cuttings from the hammer bit to the inner pipe of the string. A tubular skirt at the downhole end of the sub surrounds the hammer and channels the flow of exhaust air therebetween. A packer and uphole reamer may be included, as well as valves for air lift and for providing proper air flow direction in the borehole annulus.

Abstract: An air injection sub for use with a dual conduit drill pipe string is provided having inner and outer concentric tubular members which are connected to the corresponding inner and outer conduits of a dual conduit string to provide isolated annular and central passageways and is particularly characterized by improved injection means in the inner tubular member which allows fluid to pass from the annular passageway into the central passageway through a plurality of apertures which open into the central passageway at a plurality of levels and angular positions, is field adjustable and provides improved erosion resistance.

Abstract: A bit packer for use with a string of dual concentric drill pipe, having inner and outer tubular members concentrically arranged to mate with the inner and outer pipes of the drill string to provide an annular conduit for fluid from surface to bit and a central conduit for fluid and cuttings from bit to surface, is particularly characterized by flexible packing means mounted slidably and rotatably on the outer tubular member. The packing means deform against the hole wall to seal the annular space between the outer member and the hole wall. Upper and lower ports provide fluid communication between the annular conduit and the annular space; when the packer is moved downwardly in the hole the packing means slides upwardly to close the upper port and open the lower port; when the packer is moved upwardly in the hole, the converse occurs. A milling collar is provided above the packing means.

Abstract: A system for developing or cleaning a screened well using dual concentric drill pipe. A blind annulus injection sub and a development head are interconnected with the drill pipe and so constructed that compressed air passing down the inner pipe is directed through nozzles in the head to agitate formation water and clear the screen. When air is passed down the pipe annulus it is injected into the inner pipe and causes formation water and sand to be drawn into the head and airlifted to the surface through the inner pipe.

Abstract: An injection sub for use with a string of dual concentric drill pipe, having inner and outer tubular members concentrically arranged to mate with the inner and outer pipes of the drill string to provide continuous isolated annular and central passageways, is particularly characterized by an annular chamber in the inner member. Ports permit the flow of fluid from the annular passageway to the chamber, and apertures permit fluid flow from the chamber to the central passageway. An annular check valve in the chamber cooperates with the ports to prevent flow from the chamber to the annular passageway.