Abstract: A technique employs the use of oscillations downhole to facilitate a desired functionality of a downhole tool. According to this technique, a tool is initially conveyed downhole and operated to perform a function that relates to a downhole application. The operational efficiency of the tool is improved by creating oscillating forces which vibrate the tool to achieve a desired result, e.g. freeing the tool from a stuck position.

Abstract: A bottom-hole assembly includes a drill string extendable within a wellbore and a drill bit positioned at a distal end of the drill string. A vibration sub is positioned in the drill string axially adjacent the drill bit and includes one or more vibratory devices that impart vibration to the drill bit.

Abstract: The branching of fractures in shale formations surrounding a wellbore can be enhanced so that more rock surface is exposed in the formation and more hydrocarbon resources can be recovered using smaller quantities of fracturing fluids. The branching of the fractures can be enhanced by establishing a substantially static sub-threshold fluid pressure in a well in a geological formation, and generating a pressure pulse in the well such that the pressure pulse combined with the substantially static sub-threshold fluid pressure forms a plurality of fractures in the geological formation. An arc jet insertable into a passage in the geological formation and having an electric arc channel can be used to generate the pressure pulse.

Abstract: A hydraulic percussive apparatus is disclosed for generating vibrating forces to a pipe string. The apparatus is attached to the pipe string a central bore through which fluid may be introduced into the apparatus. The apparatus has a tubular housing, an anvil surface with an irregularly profiled surface, and a rotor with an irregularly profiled hammer surface that is urged to move axially toward and away from the anvil surface. The rotor has a longitudinally extending fluid bore and a tangentially oriented fluid port in communication with the longitudinal fluid bore of the rotor. Fluid entering the rotor's fluid bore and exiting the rotor's tangentially oriented fluid port rotates the rotor, and thus the irregularly profiled hammer surface on the irregularly profiled anvil surface, moving the hammer surface toward and away from the anvil producing intermittent impact forces.

Abstract: A wireline tractor includes a displacement mechanism and at least one driving wheel positioned on the displacement mechanism so that the driving wheel is held in a biasing manner against a well wall. The displacement mechanism is rotatable or movable between a first position at which the driving wheel bears against the well wall on one side of the wireline tractor, and a second position at which the driving wheel bears against the well wall on the opposite side of the wireline tractor.

Abstract: A downhole tool string, comprising a tool string bore and a drill bit located at the bottom of the tool string. The drill bit comprises a body intermediate a shank and a working surface. The working surface may comprise a substantially coaxial rotationally isolated jack element with a portion of the jack element extending out of an opening formed in the working surface to engage a subterranean formation. The tool string may comprise a driving mechanism adapted to rotate the jack. The clutch assembly disposed within the tool string bore may comprise a first end in communication with the jack element and second end in communication with the driving mechanism.

Abstract: A downhole drilling apparatus suspended by tubing includes a drill bit driven by an electric motor powered by a cable means. The motor is mounted upon a hollow shaft which allows fluid to pass through, so that a fluid circuit along the tube and back along the annulus between the borehole and the tubing via the drill bit is established. The state of the motor, particularly its speed and torque, can be monitored, and the motor may then be regulated as a result of the this data. Various sensors may be included in the drilling apparatus, and the data gathered similarly used to regulate the motor. Thrust means are included to urge the drill along the borehole. Supplementary pumps may be provided to assist the fluid flow. Both the thrust means and the pumps may be controlled by the control means.

Abstract: An apparatus for use in a wellbore, the apparatus comprises a top body, a bottom body, and a sleeve mechanically connected to the top and bottom bodies. The sleeve movable between a first position to a second position, whereby in the first position, the top and bottom bodies rotate as one unit and in the second position, the top body rotates independent of the bottom body in a first direction and with the bottom body in a second direction. A method for completing a wellbore, wherein the method comprises running an assembly and a liner disposed on a drill string into the wellbore. The assembly includes an expander tool, a hydraulically actuated swivel, and a running tool mechanically connected to the liner. The method includes rotating the assembly and the liner as one rotationally locked unit. The method further includes activating the expander tool, expanding the liner into the existing casing, deactivating the expander, and then removing the drill string and running assembly from the wellbore.

Abstract: Oil drilling apparatus for drilling deep boreholes. The apparatus includes a high frequency, high voltage, AC generator at the surface of the ground which is connected to an electromagnetic hammer drill bit located at the bottom of the borehole. Electric current is conducted along a special drill string to the electromagnetic hammer drill located at the bottom of the borehole. The drill string is electrically conductive to form a current flow path to the downhole electromagnetic hammer drill, while at the same time, drilling fluid flows along an axial flow path to the vibrating bit located at the bottom of the borehole. The electrically conductive drill pipe, the electromagnetic hamemr drill bit, and the pulse transformer, each form a subcombination of the present invention; and, jointly comprise a new method and apparatus for forming boreholes.

Abstract: A process for drilling spaced horizontal boreholes in a coal or other mineral deposit in excess of 1500 feet in length in a pattern determined to maximize gas removal. Directional guidance is provided by a continuous downhole survey tool connected to data display devices by an internal drill rod cable system. Apparatus is provided to permit the passage of said cable system through the interior of a rotatable drill chuck assembly comprising a part of a drilling apparatus for drilling said boreholes. The apparatus supports the cable such that the cable is maintained in a substantially nonrotating position within the drill chuck assembly. Directional drilling control is provided by a positive displacement motor positioned at the end of the drill string and operated by a flow of drilling fluid through the drill string from the drilling rig. Upon completion of the borehole, the drill string is removed and gas which enters the borehole from the surrounding deposit is withdrawn.

Abstract: A drill bit is connected to the bottom end of a longitudinally elastic drill stem which is contained within a jacket. An orbiting mass oscillator is coupled to the drill stem, this oscillator generating vibrational energy at a sonic frequency. The rotation axis of the oscillator is parallel to the drill stem, the drill stem being driven elastically, preferably at a frequency such as to set up standing waves therein, whereby circumferentially successive lengthwise oriented regions around the periphery of the column cyclically elongate and contract longitudinally in rotary progression. This longidudinal vibratory energy is transferred to the drill bit causing nutation thereof such that successive portions of the bit drive into the work material in a progression of longitudinal impulses as the stem undergoes circumferentially successive longitudinal cyclic motion in response to the vibratory energy applied thereto.

Abstract: A resilient conductor having an outer flexible insulating coating and an inner flexible conducting core is employed in a drill string to maintain an electric circuit between a subsurface and surface location. The conductor is inserted in the drill string in a generally free-hanging, random fashion to store excess length of conductor which is utilized as the drill string is lengthened. The stored conductor can be maintained in the drill string in a generally untangled state due to its kink-resistant mechanical and physical properties. Moreover, the frictional drag of the flowing drilling fluid tends to straighten and disentangle the conductor.

Abstract: Masonry cutting tool used in conjunction with a pneumatic mechanism, e.g., air-operated hammer, comprising a drill head, a plurality of cutting prongs provided on the drill head, the drill head connected to a hammer shank, and a handle removably joined to said hammer shank for rotation of the drill head during the cutting operation.