Abstract: An apparatus for boring a wellbore, including a bit body having a first end, an inner cavity, and a second end. The first end is connected to a workstring that is configured to deliver a rotational force to the bit body. The inner cavity contains a profile having a first radial cam surface. The second end includes a working face containing a cutting member. The apparatus also includes a pilot bit rotatively connected within the inner cavity. A second radial cam surface is contained on a first end of the pilot bit. The first and second radial cam surfaces are operatively configured to deliver a hammering force. A second end of the pilot bit may include an engaging surface configured to engage a formation surrounding the wellbore. The bit body rotates relative to the pilot bit.

Abstract: A torque generator for use in a bottom-hole assembly. The torque generator has a bearing pack rotationally coupled to a housing and a pump and one or more nozzles inside and supported by the housing. The one or more nozzles are in fluid communication with the pump chamber. The torque generator also has a bypass conduit extending through the pump and bypassing the pump and the one or more nozzles. The bypass conduit has a discharge end that is downhole from the pump and the one or more nozzles.

Abstract: Repeated percussive forces may be provided using various devices, systems, assemblies, and methods. Example rotary percussive devices may be used in a downhole environment, including within a drilling system that includes a percussive hammer drill bit. The rotary percussive device may include a rotational translator to convert drilling fluid pressure into a rotational force. An axial translator coupled to the rotational translator may convert the rotational force into an axial percussive force. This conversion may be done using magnets arranged in arrays of alternating polarities. The rotational translator may longitudinally overlap the axial translator. The rotational translator may include a rotational stator rotationally fixed within a bottomhole assembly. The rotational stator may include a shaft of a positive displacement motor.

Abstract: An apparatus for boring a wellbore, including a bit body having a first end, an inner cavity, and a second end. The first end is connected to a workstring that is configured to deliver a rotational force to the bit body. The inner cavity contains a profile having a first radial cam surface. The second end includes a working face containing a cutting member. The apparatus also includes a pilot bit rotatively connected within the inner cavity. A second radial cam surface is contained on a first end of the pilot bit. The first and second radial cam surfaces are operatively configured to deliver a hammering force. A second end of the pilot bit may include an engaging surface configured to engage a formation surrounding the wellbore. The bit body rotates relative to the pilot bit.

Abstract: A piston tractor system can include at least two piston assemblies which sealingly engage a wellbore, and a pump which transfers fluid between an annulus isolated between the piston assemblies, and another annulus. A method of operating a piston tractor system can include sealingly engaging at least two piston assemblies with a wellbore, grippingly engaging one piston assembly with the wellbore, and then pumping a fluid from an annulus formed between the piston assemblies, while the other piston assembly is secured to a tubular string, thereby biasing the tubular string to displace through the first piston assembly. A method of advancing a tubular string through a wellbore can include sealingly engaging piston assemblies with the wellbore, each of the piston assemblies including a gripping device which selectively grips the wellbore, and one piston assembly including another gripping device which selectively grips the tubular string.

Abstract: A drilling apparatus comprised of a multiplicity of subassemblies for drilling an open-hole extension from within an existing cased borehole located in a geological formation for the production of oil and gas. In one embodiment, one subassembly includes a motor located within a cased section of the borehole that rotates a drill pipe segment attached to a rotary drill bit in the open-hole to drill the open-hole extension of the well. In another embodiment, a shroud encloses the motor located within the cased portion of the well that is used to control the mud flow to and from the bit in the open-hole during the drilling process.

Abstract: An excitation apparatus suitable for use downhole having interengaged masses at least in part confined or guided so as to be movable as an interengaged assembly on an axis, one mass (“rotatable mass”) being rotatable relative to the other mass about the axis to cyclically vary the axial length of the assembly of the interengaged masses, a rotary drive, and an interposed spring (of any kind) between the rotary drive and the rotatable mass able to transmit torque from the rotary drive to the rotatable mass yet vary in its extent responsive to the interengaged masses.

Abstract: A directional drilling system and method are provided for directional drilling a borehole by continuous rotating of the drill string in combination with an arrangement of drilling motor assemblies at the lower end of the drill string to effect drilling along a curved path and a substantially straight path. A first drilling motor assembly is coupled to a drill bit and operable to rotate the drill bit to effect drilling of the borehole. A second drilling motor assembly, positioned on the drill string above the first drilling motor assembly, is operable to rotate the first drilling motor assembly in a direction opposite the direction of rotation imparted to the drill string from the surface and to the drill bit by the first drilling motor assembly.

Abstract: A turbine for use in a downhole drill string including an elongated casing defining an interior and a plurality of motor units in the interior. Each motor unit has a rotor and a stator. A torque transmission couplings connects each of the plurality of motor units to the drill string. The torque transmission couplings having flexible linkages. As a result, the power section has tight tolerances for the clearance at the tips of the rotors because the motor units are relatively stiff. The flexing normally obtained by bending the rotor shaft is accomplished and absorbed in the flexible linkages.

Abstract: A bottom-hole assembly for directional drilling incorporates a torque generator with a drive shaft connected to a drill string. The torque generator generates a torque that counters a reactive torque when a drill bit of the bottom-hole assembly is driven. When the drill string is rotated at a static drive speed, a drill tool face of the bottom-hole assembly is stabilized to drill a nonlinear bore segment. When the drill string is rotated at a rotational speed other than the static drive speed the bottom-hole assembly is rotated to drill a linear bore segment.

Abstract: A method of prolonging the life of a PDC cutter having a substantially cylindrical shape centered about a rotational axis, and an apparatus for multi-axis modulation of a PDC cutter, the method including imparting linear modulation to the cutter in at least one direction and imparting rotary modulation to the cutter about the rotational axis, the rotary modulation being synchronized with, and facilitated by, the linear modulation.

Abstract: A method for forming a subsurface wellbore is disclosed. The method includes operating a drilling string in a first direction of rotation. A first motor located near the end of the drilling string is operated in a direction of rotation opposite that of the drilling string. A drill bit is rotated using a second motor that is coupled to the first motor.

Abstract: A progressing cavity pump/motor includes an upper stator tube (14), a lower stator tube (16), a rotor (20) sitting between the upper and lower stator tubes, and a coupling assembly (30) interconnecting the stator tubes comprising an outer sleeve (32), an inner sleeve (36) and a nut (60) for threaded engagement with at least one of the sleeves to bring a stop surface on the inner sleeve into mating engagement with the stop surface on the outer sleeve. The pump/motor is usually assembled in the field while maintaining precise axial and rotational positioning of the stator tubes.

Abstract: A bottom hole assembly (BHA) for use in drilling a wellbore includes: a first mud motor having a stator and a rotor; a second mud motor having a stator and a rotor; a drill bit rotationally coupled to the second rotor and having a tool face and a longitudinal axis inclined relative to a longitudinal axis of the first mud motor; and a clutch. The clutch is operable to: rotationally couple the second stator to the first stator in a first mode at a first orientation of the tool face, rotationally couple the first rotor to the second stator in a second mode, change the first orientation to a second orientation by a predetermined increment, orient the tool face at the second orientation in an orienting mode, and shift among the modes in response to a change in flow rate of a fluid injected through the clutch and/or a change in weight exerted on the drill bit.

Abstract: A drive mechanism is described for moving/controlling objects/mechanisms/systems coupled with a drillstring and/or pipe. The drive mechanism may be axially arranged on a drillstring or pipe, compact, capable of fine control and delivering high torque or the like and may be electrically and/or hydraulically powered. The drive mechanism may comprising a driving member comprising a plurality of drivers linearly translatable with respect to the driving member, each driving member having at their ends a male engaging portion and an associated driven member, comprising a plurality of female receiving portions adapted to receive a male engaging portion, the arrangement being such that linear translation of a driver causes its engaging portion to engage with a female receiving portion and the action of the engaging portion produces a reaction in the receiving portion causing displacement of the driven member in a direction other than that of the translatable driver.

Abstract: The invention provides a drilling system for use in a borehole through an underground formation, comprising: a drilling assembly including a drill bit for drilling through the formation and a drilling drive; conveyance means including a conveyance drive connected to the drilling assembly and operable to move the drilling assembly through the borehole, wherein the conveyance drive is operable to move the drilling assembly along the borehole into a drilling position and the drilling drive is operable to urge the drill bit into contact with the formation when drilling takes place in the drilling position.

Abstract: A turbine for use in a downhole drill string including an elongated casing defining an interior and a plurality of motor units in the interior. Each motor unit has a rotor and a stator. A torque transmission couplings connects each of the plurality of motor units to the drill string. The torque transmission couplings having flexible linkages. As a result, the power section has tight tolerances for the clearance at the tips of the rotors because the motor units are relatively stiff. The flexing normally obtained by bending the rotor shaft is accomplished and absorbed in the flexible linkages.

Abstract: A method for forming a subsurface wellbore is disclosed. The method includes operating a drilling string in a first direction of rotation. A first motor located near the end of the drilling string is operated in a direction of rotation opposite that of the drilling string. A drill bit is rotated using a second motor that is coupled to the first motor.

Abstract: Embodiments of the present invention generally relate to a flow operated orienter. In one embodiment, a bottom hole assembly (BHA) for use in drilling a wellbore includes: a first mud motor having a stator and a rotor; a second mud motor having stator and a rotor; a drill bit rotationally coupled to the second rotor and having a tool face and a longitudinal axis inclined relative to a longitudinal axis of the first mud motor; and a clutch. The clutch is operable to: rotationally couple the second stator to the first stator in a first mode at a first orientation of the tool face, rotationally couple the first rotor to the second stator in a second mode, change the first orientation to a second orientation by a predetermined increment, orient the tool face at the second orientation in an orienting mode, and shift among the modes in response a change in flow rate of a fluid injected through the orienter and/or a change in weight exerted on the drill bit.

Abstract: An earth boring apparatus for sinking shafts and removing shaft material from the shaft, the apparatus having at least two decks; hydraulic means for allowing movement of the decks relative to one another; releasable anchoring means associated with the decks for engaging walls of the shaft to secure the apparatus in a stationary position; whereby the releasable anchoring means of one of the decks engages the wall while the releasable anchoring means of the other deck is released from the wall to allow motion of the other deck along the shaft, in cooperation with the hydraulic means. The apparatus also includes guide means for forcing a bucket for hoisting shaft material from the shaft along a predetermined path, and an in-stage cut-boom drill.

Abstract: A device is provided for manipulating a tool in a well tubular. The device includes a cylindrical housing having a front end and a rear end, and radially extendible dogs for securing the device in the well tubular. A shaft is also included that is axially displaceable and rotatable from the front end of the device. The shaft is extendable from a displaceable sleeve, the displaceable sleeve also being extendable from the front end of the device. The outwardly extending end parts of the shaft and of the sleeve are provided with is effective for holding a tool.

Abstract: An improved coiled tubing directional drilling method comprises: providing a bent housing which is rotatably coupled to the coiled tubing, rotating the drill bit, and rotating the bent housing. Apparatus for achieving the method comprises: a rotary connection between the coiled tubing and the bent housing and means for rotating the bent housing relative to the coiled tubing and to the drill bit. A fluid pressure-operated clutch enables alternate rotation and locking of the bent housing. Preferably, a first downhole motor rotates the drill bit and a second downhole motor rotates the bent housing through the clutch or alternately a speed reducer permits the bent housing to contra-rotate slowly under reactive torque developed by the rotating drilling bit.

Abstract: Improvements for a downhole flexible drive system for drilling high angle well holes or curved holes from the vertical to the horizontal with an ultra short radius to drill a horizontal drain hole. The improvements include a flexible shaft that connects the drive train of the system to a swivel joint attached inside the uphole tool joint of the system, that provide the drive train of the system the capability to carry part or all the tension loads on the system. An exhaust collar is provided with deflectors that direct excess drilling fluid up a well hole. A pump section is provided to insure drilling fluid flow over the face of a drill bit and the transport of cuttings. To increase flexibility and limit the length of inflexible sections of the system, a flexible tube to carry drilling fluids connects the bearing pack to the system.

Abstract: A drilling assembly for drilling holes in subsurface formations comprises a drill bit 10, a drive unit 12 including a housing and a rotor 11 operatively coupled to the drill bit to rotate the drill bit relative to the housing, and a modulated bias unit 14 coupled to rotate with the drive unit housing and apply a lateral bias thereto in synchronism with rotation of the housing. The modulated bias unit 14 comprises one or more hydraulic actuators including members 16 which, in use, bear against the sides of the borehole, and means for modulating the pressure of fluid supplied to the actuators in synchronism with rotation of a component of the drilling assembly, and in selected angular phase relation thereto, whereby each hydraulic actuator is actuated in a selected rotational position of the component.

Abstract: A self-propelled drill for drilling a bore or cleaning a pipe in straight and/or curved paths. The drill includes a piston having a working head which slides within a housing. A rotary piston driving mechanism featuring an endless groove converts longitudinal motion of the piston to a combined longitudinal and rotary movement of the working head. A housing gripping device fixes the drill to the wall of the bore to allow drilling while a working head gripping device fixes the working head to the walls of the bore to allow the drill to be periodically pulled forward.

Abstract: The tandem drilling motor includes an upper power section comprised of an upper rotor and stator and a lower power section comprised of a lower rotor and stator. A connector having a flowbore therethrough has one end attached to one end of the upper rotor and another end connected to an end of the lower rotor. The upper and lower rotors have a bore therethrough for the passage of drilling fluid. The flowbore of the connector communicates with the bores of the upper and lower rotor whereby drilling fluid may pass through the bore of the upper rotor, the flowbore of the connector, and the bore of the lower rotor. The drilling fluid exits the lower rotor through a port adjacent its lower end. The connector includes transition bores at each end to avoid turbulent flow through the connector.

Abstract: In a process for laying underground service lines without excavation by means of a ram boring machine, old pipe lines already buried underground are replaced by new service lines without having to tear up the ground or destroy the old pipe line. To enable the new line to be laid accurately in position and to be accurately targeted the ram boring machine is provided with a guiding bore passing axially through the casing and is guided on the old line.

Abstract: An apparatus for compacting soil includes a tamping shoe with anvils, a reaction mass with an anvil and an impact mechanism comprising a crank gear installed in a casing and having hammer rams which are oppositely directed and which are coaxial with the anvils of the tamping shoe and reaction mass.

Abstract: A self-propelled drilling head comprises a base section including gripper shoes mounted for extension and retraction to selectively grip the wall of a hole being drilled. A first actuator is provided for extending and retracting the gripper shoes. A drilling section is mounted on the base for reciprocation relative thereto. A second actuator is provided for urging the drilling section downwardly relative to the base section when the gripper shoes are extended. A cutter bit is mounted at a lower end of the drilling section. A third actuator is provided for rotating the cutter bit and comprises a first hydraulic motor having a first output shaft. A second hydraulic motor is spaced below and laterally offset from the first hydraulic motor and has a second output shaft extending parallel to the first output shaft. A driven gear is mounted at the end of each output shaft. A drive transmitting gear mechanism is meshingly engaged on opposite sides by the driven gears.

Abstract: A surface drilling apparatus for drilling large diameter holes in soft to medium-hard earth formations includes a cylindrical casing defined by a stationary upper section and a lower section rotatable relative to the upper section; a plurality of circular rows of cutting discs rotatably mounted on the base of the lower section for cutting material beneath the apparatus; a transfer pipe in the center of the base of the lower section for receiving cut material from the cutting discs and feeding the cut material upwardly through a discharge pipe for carrying the material upwardly to the surface; and an annular, upwardly inclined slot in the discharge pipe at the top of the upper section through which air is fed under pressure into the discharge pipe to induce the cut material upwardly from the transfer pipe and blow the material upwardly.

Abstract: An improved downhole system for operating a drill bit around a small radius of bend in the directional drilling of curved holes from a vertical well hole in an oil or gas formation. The system is comprised of a plurality of double shaft downhole motors assembled in line and their shafts are connected by a flexible coupling. A flexible assembly encloses the area between the motors and provides a means for drilling fluids to be pumped through the system to a drill bit. The system can be constructed of either electrical motors or fluid turbine motors which can operate from drilling fluids pumped down a drill pipe string.

Abstract: An improved downhole system for operating a drill bit around a small radius of bend in the directional drilling of curved holes from a vertical well hole in an oil or gas formation. The system is comprised of a plurality of double shaft downhole motors assembled in line and their shafts are connected by a flexible coupling. A flexible assembly encloses the area between the motors and provides a means for drilling fluids to be pumped through the system to a drill bit. The system can be constructed of either electrical motors or fluid turbine motors which can operate from drilling fluids pumped down a drill pipe string.

Abstract: A hydraulic motor for use in a drill string is disclosed. The motor incorporates a closed hydraulic system having a piston exposed to variations in mud flow pressure. The piston reciprocates and by its movement pumps hydraulic fluid in a closed hydraulic circuit. A motor is driven. The motor is supported on a hollow drive shaft. The drive shaft extends through the tool. It is hollow to permit mud flow to continue to the drill bit attached therebelow. The motor is attached to the exterior and rotates the shaft. The hydraulic fluid from the motor is returned to a reservoir and flows in a closed circuit from it. All of the equipment is in a closed elongate housing threading into the drill string.

Abstract: A turbine-powered intensifier assembly is a part of a drill collar and attaches to the downhole end of a drill string. A drilling mud stream from the drill string branches. One branch is cleaned of solid matter by centrifugal cleaners. The clean fluid drives the turbines of several stages of turbine-pump intensification and a turbine drive of the centrifugal cleaners. The turbine intakes are in parallel. Each turbine drives a pump and the pumps are staged in series so that the output of one pump becomes the input of a downstream pump. The clean fluid also supplies the pump fluid. The discharge of the final pump stage exhausts into nozzles which direct the fluid against bore hole rock at extremely high pressures and erodes the rock. Turbine exhaust and drilling mud not used in the intensification empties into the rock erosion zone to clear it of chips formed by the drilling. Fluid from this zone and dirty fluid from the cleaners pass up the annulus between the bore hole and the drill string.

Abstract: Method of and apparatus for extracting oil from oil shale. An excavating unit is driven by supplying steam to a plurality of steam engines mounted in an annulus between stationary outer and inner casings. A hollow center column and apertured screw vane are mounted for rotation in the inner casing and helical screw sections are provided outwardly of the inner casing at both ends of the apparatus for directing material to and from the inner casing. Steam is supplied to the unit for driving the center column and helical screws, with the steam supplied to the center column emanating through openings in the screw vane mounted in the inner casing for separating the oil from the oil shale by pyrolysis. The oil is withdrawn in the form of a vapor product by means of a vacuum applied to the inner casing for separation and condensation at the surface. Following excavation, the unit can be withdrawn to the surface under its own power.