Abstract: This invention relates to a steerable drill bit arrangement, in particular for the use in drilling boreholes for oil and gas extraction. According to the invention there is provided a steerable drill bit arrangement comprising a drill bit, a steering component and a stabilizer, the steering component being adapted to provide a steering force which in use can drive the drill bit along a non-linear path, the stabilizer being located between the drill bit and the steering component and in use providing a fulcrum for the steering force provided by the steering component, the position of the fulcrum provided by the stabilizer being adjustable relative to the drill bit and the steering component. In use, the position of the fulcrum can be adjusted to vary the maximum curvature of the borehole and to suit the rock type(s) being drilled.

Abstract: Embodiments include ball piston steering devices and methods for use of ball piston devices. In one aspect a ball piston steering device includes a sleeve in fluid communication with a fluid source and a ball received within the sleeve. The ball is movable within the sleeve between a recessed position and an extended position.

Abstract: The present invention provides a directional drilling apparatus and method for use in drilling bore holes. The apparatus comprises a plurality of movably mounted cutting elements, wherein the cutting elements are movable between radially retracted and extended cutting positions. A rotary valve is provided for synchronizing the movement of the cutting elements between their respective extended and retracted positions. Control of the directional drilling system is affected by synchronized movement of the cutting elements from an inner to an outer radial position in accordance with the angular position of the drill bit. Means are provided for directing high pressure cutting fluid to the region between the cutting elements and the rotatable body to prevent the accumulation of debris that could prevent movement of the cutting elements. The cutting elements enlarge the bore hole formed by the drill bit, so that the cutting elements continuously engage the wall of the bore hole.

Abstract: A steering head for use with a casing, the steering head having a generally cylindrical body with a first body end with a lead edge, a second body end with a rear edge, and a body surface extending from the lead edge to the rear edge, an outer tube with an internal side generally facing the body surface, the outer tube extending from the first body end to the second body end, and a steering flap disposed on an external side of the outer tube having a first flap face facing radially inwardly and a second flap face facing radially outwardly. A biased hinge is secured to both the outer tube and the steering flap, the biased hinge being operative to retract the steering flap into a retracted position from an extending position.

Abstract: A drill bit is provided that includes a force application device on a body of the drill bit. The force application device includes a force application member pivotally coupled to the drill bit and configured to extend from the drill bit body to apply force on a wellbore wall when the drill bit is used to drill a wellbore, and an actuator configured to actuate the force application member to apply force on a wellbore wall during drilling of the wellbore.

Abstract: A method and apparatus for stabilizing a downhole tool during a downhole operation. The method and apparatus include a stabilizer having a stabilization member adapted to move between a retracted position and an extended position in order to engage a surface in a wellbore. The stabilizer also includes a plurality of actuators adapted to move the stabilization members from the retracted position to the extended position.

Abstract: A downhole, hydraulically actuated drilling stabilizer that provides versatility in a bottom-hole assembly. The drilling stabilizer can be used in a directional drilling application to help control the inclination in an extended reach or horizontal well. The drilling stabilizer has stabilizer blade members with an angular design portion that provides versatility in a bottom-hole assembly. The stabilizer could also be used in a conventional rotary bottom-hole assembly, or positioned below a steerable motor.

Abstract: A rotary steerable tool is provided for use with a drilling apparatus. The rotary steerable tool includes at least a first portion that includes an outer housing, a rotary shaft extending through the outer housing, a drive clutch coupled to the rotary shaft, and a sensor coupled to the rotary shaft. The drive clutch is movable between an engaged configuration and a disengaged configuration. The sensor is configured to identify whether the drive clutch is in at least one of the engaged configuration and the disengaged configuration.

Abstract: A transport assembly configured to be attached to downhole apparatus has a support assembly configured to be attached to the downhole apparatus and a ground engaging assembly, which may be a roller wheel configured to contact with and move in relation to a surface of a wellbore. The roller wheel may engage with the support assembly so as to provide for their relative rotation. The transport assembly also includes a retaining member disposed between the roller wheel and the support assembly, and the retaining member is operable to resist separation of the roller wheel from the support assembly. The transport assembly is further configured such that, when the transport assembly is in use moving along a wellbore, the roller wheel bears against the retaining member, which in turn bears against the support assembly. The retaining member is a ball-bearing.

Abstract: A steerable system comprises a fluid powered motor 10 having a rotor 16 and a stator 18, and a bias arrangement having a plurality of bias pads 34 connected to the stator 18 so as to be rotatable therewith, the bias pads 34 being moveable to allow the application of a side load to the steerable system.

Abstract: A rotary steerable tool (2) for use in a downhole drilling apparatus for adjusting the direction of drilling is disclosed. The tool comprises a tubular outer housing (20) and a row of steering pushers (24) slidably mounted to the housing for movement between an extended position, in which the steering pusher engages a wall of a borehole formed by the drilling apparatus, and a withdrawn position, in which the steering pushers do not engage the wall of the borehole. A tubular sleeve (4) is mounted inside the housing (20) to transmit rotary drive to a drilling bit. A pressure chamber (22) defined between the sleeve (4) and the housing (20) communicates with the steering pushers (24) to move the steering pushers (24) to the extended position.

Abstract: A downhole steering tool includes distinct hydraulic and electronics modules deployed about a shaft. The hydraulics module includes a plurality of hydraulically actuated blades. The electronics module includes electronic circuitry configured to control blade actuation. The hydraulics and electronics modules are physically and electrically connected to one another via a timed connection.

Abstract: One embodiment includes an apparatus comprising a steerable well bore drilling tool having a main tool body. The steerable well bore drilling tool includes an inertial measurement unit to output a measurement used to determine an azimuthal deviation and inclination of the steerable well bore drilling tool during a drilling operation.

Abstract: In an aspect, a drill bit is provided that includes at least one blade profile having a side section and an adjustable pad on the side section that is configured to extend from the side section to cause the drill bit to alter a drilling direction when the drill bit is used to drill a wellbore. In addition, the drill bit may also include a fluid line configured to supply a fluid under pressure to the pad to cause the pad to extend from the side section.

Abstract: A direction adjustment tool for a downhole drilling apparatus is disclosed. The tool has a tubular housing adapted to be incorporated into a downhole drilling apparatus, and steering blades mounted to the housing. A drive shaft transmits drive to a drill bit of a drilling apparatus, wherein the shaft defines a passage for transmitting drilling fluid to the drill bit. A first pressure chamber is defined between the housing and the shaft and communicates with the passage, wherein the steering blades are moved from retracted positions to extended positions thereof as a result of increase of fluid pressure the first pressure chamber. A pendulum member is pivotably mounted to extend in a vertical orientation when the shaft is not rotating relative to the housing, and pistons prevent movement of at least one steering blade to the extended position thereof as a result of the angle between a longitudinal axis of the shaft and the longitudinal axis of the pendulum member exceeding a predetermined amount.

Abstract: A steering tool configured for making azimuthal and non-azimuthal formation evaluation measurements is disclosed. In one embodiment a rotary steerable tool includes at least one formation evaluation sensor deployed in the steering tool housing. The steering tool may include, for example, first and second circumferentially opposed formation evaluation sensors or first, second, and third formation evaluation sensors, each of which is radially offset and circumferentially aligned with a corresponding one of the steering tool blades. The invention further includes methods for geosteering in which a rotation rate of the steering tool housing in the borehole (and therefore the rotation rate of the formation evaluation sensors) is controlled. Steering decisions may be made utilizing the formation evaluation measurements and/or derived borehole images.

Abstract: Hydrostatic bearings are used for drill string stabilization and bottom hole assembly steering. The hydrostatic bearings utilize an existing mud flow as the bearing fluid. For steering, the bearings may be used between movable kick pads and the formation to reduce friction. Alternatively, differential hydrostatic bearing pressure may be utilized to steer. Multi-modal (non-linear and linear) steering may be provided by selectively applying equal and unequal hydrostatic bearing pressures. The bearings can be made more tolerant of imperfections in the formation by utilizing multiple pressure pockets.

Abstract: A steerable drilling system comprises a rotary drill bit 14 secured to a housing 16, a secondary rotary drill component 22 carried by the housing and rotatable therewith, the second rotary drill component 22 having a gauge dimension greater than that of the rotary drill bit 14, and a drive arrangement operable to displace the secondary rotary drill component 22 relative to the housing 16 while maintaining an axis 24 of the secondary rotary drill component 22 substantially parallel to an axis 18 of the housing 16.

Abstract: A drill bit is provided that in one embodiment may include a force application device on a drill bit body, wherein the force application device includes a force application member pivotally coupled to the drill bit and configured to extend from the drill bit body to apply force on a wellbore wall when the drill bit is used to drill a wellbore, and an actuator configured to actuate the force application member to apply force on a wellbore wall during drilling of the wellbore.

Abstract: Drilling systems and methods for enlarging a borehole that include an expandable reamer and an expandable stabilizer axially coupled above the expandable reamer are disclosed. The expandable reamer includes a tubular body having a longitudinal axis and a drilling fluid flow path therethrough, a plurality of generally radially and longitudinally extending blades carried by the tubular body, and a cutting structure carried by at least one blade of the plurality of blades, wherein at least one blade of the plurality of blades is movable outwardly with respect to the longitudinal axis. The expandable stabilizer includes a tubular body having a longitudinal axis and a drilling fluid flow path therethrough, a plurality of generally radially and longitudinally extending bearing pads carried by the tubular body, wherein at least one bearing pad of the plurality of bearing pads includes an up-hole cutting structure carried thereupon and is movable outwardly with respect to the longitudinal axis.

Abstract: An exemplary device carried on a rotating drill string includes an actuator that moves force application members and an associated controller. The force application members are actuated by an eccentricity between a force application members housing and the actuator. The controller synchronizes the extension of the force application members with the rotation of the drill string such that a steering force applied by the force application members is applied in the same azimuthal direction. The controller may also control magnitude of the steering force by adjusting the eccentricity. Another exemplary device maintains a wellbore device, such as a sensor, in a substantially non-rotating condition relative to a reference frame. The device includes a sensor conveyed by a rotating wellbore tubular, a drive configured to rotate the sensor; and a processor that controls the drive to maintain the sensor in a substantially non-rotating condition relative to the reference frame.

Abstract: The invention relates to a downhole device for incorporation into a downhole string and movement in a wellbore. The device comprises a body member, at least one roller arranged on the device to engage the inner surface of the wellbore and means to orient the device in the wellbore. The means to orient the device are provided on the or each roller. Preferably the means to orient the device comprise a projecting portion provided on the or each roller which projects radially outwardly from the body member. The projecting portion can be an eccentrically-shaped portion of the or each roller.

Abstract: A bottom hole assembly to directionally drill a subterranean formation includes a drill bit, a stabilizer assembly located proximate to and behind the drill bit, a drilling assembly comprising a drive mechanism and a directional mechanism, and a flex member. Optionally, the flex member may be located between the drilling assembly and the stabilizer assembly or an integral to a housing of the drilling assembly. A method to drill a formation includes positioning a stabilizer assembly behind a drill bit and positioning a flex member between an output shaft of a drilling assembly and the stabilizer assembly. The method preferably includes rotating the drill bit, stabilizer assembly, and flex member with a drilling assembly and directing the trajectory of the drill bit and stabilizer assembly with a directional mechanism of the drilling assembly.

Abstract: A directional drilling apparatus for use in the directional drilling of bore holes is disclosed. The apparatus comprises a plurality of cutting elements movably mounted with respect to a rotatable body member, wherein the cutting elements are movable between first, radially retracted, positions and radially extended, positions for cutting. A rotary valve is provided for synchronising the movement of the cutting elements between their respective extended and retracted positions in accordance with the rotational position of the body member in the bore hole being drilled. Control of the directional drilling system is affected by synchronised movement of the cutting elements from an inner to an outer radial position in accordance with the angular position of the drill bit. A near bit stabiliser contacts with the portion of the well bore which was not removed with the dynamic cutters and this contact exerts a force onto the drill bit.

Abstract: Sleeves, stabilizers and other well tools may be formed with fluid flow paths or channels extending through one or more blades disposed on the exterior portions of such well tools. The blades and associated fluid flow paths extending therethrough may allow optimum fluid flow rates and volumes to enhance lifting of formation cuttings and downhole debris along with cleaning exterior portions of the well tool and an associated rotary drill bit. Location, configuration, orientation and/or dimensions associated with such blades and associated fluid flow paths or channels may also be modified to provide an enlarged pad or contact surface on exterior portions of one or more blades while maintaining desired fluid flow rates and volumes over exterior portions of the well tool. Such pads or contact surfaces may have optimum surface areas for contacting adjacent portions of a wellbore during directional drilling of the wellbore.

Abstract: Methods and systems may be provided simulating forming a wide variety of directional wellbores including wellbores with variable tilt rates and/or relatively constant tilt rates. The methods and systems may also be used to simulate forming a wellbore in subterranean formations having a combination of soft, medium and hard formation materials, multiple layers of formation materials and relatively hard stringers disposed throughout one or more layers of formation material. Values of bit walk rate from such simulations may be used to design and/or select drilling equipment for use in forming a directional wellbore.

Abstract: A steering head for use with an auger and a casing engaged to the auger, the steering head comprising: a generally cylindrical body having a first body end and a second body end mountable to the casing, a bore channel concentrically received in the body, a front lip, a rear lip, a body surface, and a lead edge; an outer tube having an internal side covering the body surface and an opposing external side; a steering flap disposed on the external side of the outer tube having a first flap face and a second flap face, a distal end, and a hinge end, the steering flap disposable in a retracted position and an extended position; a biased hinge operative to retract the steering flap into the retracted position; and a powered actuator operative to extend the first flap face into the extended position.

Abstract: A directional-control apparatus for a drilling tool, in which the direction of the drilling tool during the drilling of a borehole is controlled by means of at least one steering body which is moved radially against the wall of the borehole, the movement of the at least one steering body relative to the centre axis of the directional-control apparatus being adjustable in order to steer the drilling tool in a desired direction and at a desired deflection, and at least one electrically operated actuator being connected via at least one set of transmission elements to the at least one steering body and arranged to move the at least one steering body into a position relative to the centre axis of the directional-control apparatus, the relative position having the effect that the drilling tool is steered in the desired direction and at the desired deflection.

Abstract: Drilling apparatuses and methods for limiting precession are provided. According to one embodiment, a drilling apparatus includes a non-rotating stabilizer. The non-rotating stabilizer includes a first blade and a second blade, the first blade being arranged opposite the second blade. The first blade is biased radially outwardly by a force of a first value. The second blade is not biased radially outwardly by a force corresponding to the first value. The second blade may be a blade which is slidable along the non-rotating stabilizer in an axial direction and allow free sliding axial contact with the formation.

Abstract: A downhole tool includes a non-contact, electrical coupling device configured to transmit electrical power and/or data between relatively rotating components. In one embodiment, the coupling device includes at least first and second wound toroidal cores deployed about a shaft. At least one of the wound toroidal cores is rotationally fixed to the shaft, while at least one other is rotationally fixed to a housing in which the shaft is deployed. The shaft forms a portion of a conductive loop that extends through the toroids. A non-contact electrical pathway is advantageously provided for high power electrical transmission and/or high speed data transmission across a gap between first and second rotating members of a downhole assembly.

Abstract: The present disclosure relates to a cutting component for a tunneling apparatus. The cutting component includes a cutting unit main body having a front cutting side and a rear side. The cutting unit main body includes a hub portion defining a socket providing a torque transfer interface. The socket extends through the hub portion in a rear-to-front orientation and has an open end at least at the rear side of the cutting unit main body. The cutting unit main body defines an axis about which the cutting unit main body is rotated during cutting. The axis extends through a central region of the socket in the rear-to-front orientation. The cutting unit main body also including a plurality of cutting arms connected to the hub portion. The cutting arms project generally radially outwardly from the axis.

Abstract: A direction adjustment tool 2 for a downhole drilling apparatus is disclosed. The tool has a tubular housing 8 adapted to be incorporated into a downhole drilling apparatus, and steering blades 10 mounted to the housing. A drive shaft 16 transmits drive to a drill bit of a drilling apparatus, wherein the shaft defines a passage for transmitting drilling fluid to the drill bit. A first pressure chamber 32 is defined between the housing and the shaft and communicates with the passage, wherein the steering blades are moved from retracted positions to extended positions thereof as a result of increase of fluid pressure the first pressure chamber.

Abstract: The invention provides ball piston steering devices and methods for use of ball piston devices. One aspect of the invention provides a ball piston steering device including: a sleeve in fluid communication with a fluid source and a ball received within the sleeve. The ball is movable within the sleeve from a recessed position and an extended position.

Abstract: A rotary steerable apparatus is provided having an actuator for pushing the bit or pointing the bit that includes a shape memory alloy. An elongated form of the alloy, such as a wire or rod, is employed in a mechanism that applies force in a direction transverse to the wellbore in response to a change in length of the alloy. Temperature of the alloy is controlled to change shape and produce the desired force on pads for operating the apparatus. The apparatus may be used with downhole power generation and control electronics to steer a bit, either in response to signals from the surface or from downhole instruments.

Abstract: A method is provided for conducting measurements of a borehole while drilling the borehole in a geological formation. First, a rotatable drilling assembly is provided that has, at a forward end, a drill bit and a borehole measurement tool connected rearward of the drill bit. The measurement tool includes at least one caliper arm extendible outward from the measurement tool. The method involves drilling the borehole by operating the rotatable drilling assembly. While drilling, the wall of the borehole is contacted with at least one extendable caliper arm of the borehole measurement tool and the extension of the caliper arm contacting the borehole wall is measured, thereby determining a distance between the measurement tool and the borehole wall. During rotation of the drilling assembly, contact is maintained between the caliper arm and the borehole wall and the measuring step is repeated at multiple positions of the drilling assembly.

Abstract: A purely mechanical hydraulic control system includes at least one drilling fluid chamber and a hydraulic fluid chamber. A system pressure spring is deployed in one of the drilling fluid chamber(s) between a positioning piston and a system pressure piston. The spring is disposed to pressurize oil in the hydraulic fluid chamber via applying a spring force to the system pressure piston. When the system is actuated (e.g., via turning on the mud pumps), the positioning piston is urged in place against a stop (e.g., a shoulder) thereby compressing the system pressure spring and pressurizing oil in the hydraulic chamber. The invention advantageously converts highly variable drilling fluid pressure to a near constant pressure hydraulic fluid.

Abstract: The present disclosure relates to an auger boring machine for boring through the earth. The auger boring machine includes a cutting head for engaging a working face of the earth to cut a bore. The cutting head is rotatable about a drive axis so as to cut the earth at the working face. The auger boring machine further includes an auger that is rotatable about the drive axis for transporting spoil resulting from the operation of the cutting head away from the cutting head. Additionally, the auger boring machine includes a casing housing the auger which is urged to move into the bore behind the cutting head. The cutting head and the auger are movable along the drive axis relative to the casing. Furthermore, the auger boring machine includes a steering member positioned near the cutting head for directing movement of the casing into the bore in a steered direction transverse to the drive axis.

Abstract: The present invention provides a directional drilling apparatus and method for use in drilling bore holes. The apparatus comprises a plurality of movably mounted cutting elements, wherein the cutting elements are movable between radially retracted and extended cutting positions. A rotary valve is provided for synchronizing the movement of the cutting elements between their respective extended and retracted positions. Control of the directional drilling system is affected by synchronized movement of the cutting elements from an inner to an outer radial position in accordance with the angular position of the drill bit. Means are provided for directing high pressure cutting fluid to the region between the cutting elements and the rotatable body to prevent the accumulation of debris that could prevent movement of the cutting elements. The cutting elements enlarge the bore hole formed by the drill bit, so that the cutting elements continuously engage the wall of the bore hole.

Abstract: A drilling stabilization system includes a power section coupled to an upper end of a transmission housing, a bearing housing coupled to a lower end of the transmission housing, and a drill bit coupled to the bearing housing, wherein the transmission housing includes at least two radially outwardly extending blades disposed on the transmission housing. A method of drilling a substantially concentric wellbore includes drilling a formation with a directional drilling bottomhole assembly coupled to a drill string, changing a direction of the drilling of the formation being drilled, removing the directional drilling bottomhole assembly from the drill string, coupling a drilling stabilization system to the drill string, and drilling the formation with the drilling stabilization system.

Abstract: A method and apparatus for detecting and avoiding an underground object during a horizontal directional drilling operation. The apparatus comprises a boring tool with a ground penetrating radar detection system. The boring tool is operatively connected to a drill string and advanced through the earth to create a borehole. The radar detection system includes at least one transmitter, at least one detector, and a processor. The transmitter is located on a surface of the boring tool and is adapted to transmit electromagnetic waves. At least one detector is located on the surface of the boring tool, and detects the electromagnetic waves reflected by underground objects. The processor determines the location of the underground object from characteristics of the reflected waves. Using this information, the drill string may be pulled back up the borehole or redirected to avoid the object. The boring tool may be caused to breakout of the existing borehole using a pivoting boring tool.

Abstract: This disclosure relates in general to a method and system for controlling a drilling system for drilling a borehole in an earth formation. More specifically, but not by way of limitation, embodiments of the present invention provide systems and methods for controlling dynamic interactions between the drilling system for drilling the borehole and an inner surface of the borehole being drilled to steer the drilling system to directionally drill the borehole. In another embodiment of the present invention, data regarding the functioning of the drilling system as it drills the borehole may be sensed and interactions between the drilling system for drilling the borehole and an inner surface of the borehole may be controlled in response to the sensed data to control the drilling system as the borehole is being drilled.

Abstract: This disclosure relates in general to a method and system for controlling a drilling system for drilling a borehole in an earth formation. More specifically, but not by way of limitation, embodiments of the present invention provide systems and methods for controlling dynamic interactions between the drilling system for drilling the borehole and an inner surface of the borehole being drilled to steer the drilling system to directionally drill the borehole. In another embodiment of the present invention, data regarding the functioning of the drilling system as it drills the borehole may be sensed and interactions between the drilling system for drilling the borehole and an inner surface of the borehole may be controlled in response to the sensed data to control the drilling system as the borehole is being drilled.

Abstract: A method and apparatus for detecting and avoiding an underground object during a horizontal directional drilling operation. The apparatus comprises a boring tool with a ground penetrating radar detection system. The boring tool is operatively connected to a drill string and advanced through the earth to create a borehole. The radar detection system includes at least one transmitter, at least one detector, and a processor. The transmitter is located on a surface of the boring tool and is adapted to transmit electromagnetic waves. At least one detector is located on the surface of the boring tool, and detects the electromagnetic waves reflected by underground objects. The processor determines the location of the underground object from characteristics of the reflected waves. Using this information, the drill string may be pulled back up the borehole or redirected to avoid the object. The boring tool may be caused to breakout of the existing borehole using a pivoting boring tool.

Abstract: A rotary steerable tool for use in a downhole drilling apparatus for adjusting the direction of drilling is disclosed. The tool comprises a tubular outer housing and a row of steering pushers slidably mounted to the housing for movement between an extended position, in which the steering pusher engages a wall of a borehole formed by the drilling apparatus, and a withdrawn position, in which the steering pushers do not engage the wall of the borehole. A tubular sleeve is mounted inside the housing to transmit rotary drive to a drilling bit. A pressure chamber defined between the sleeve and the housing communicates with the steering pushers to move the steering pushers to the extended position.

Abstract: This invention relates to a steerable drill bit arrangement, in particular for the use in drilling boreholes for oil and gas extraction. According to the invention there is provided a steerable drill bit arrangement comprising a drill bit, a steering component and a stabilizer, the steering component being adapted to provide a steering force which in use can drive the drill bit along a non-linear path, the stabilizer being located between the drill bit and the steering component and in use providing a fulcrum for the steering force provided by the steering component, the position of the fulcrum provided by the stabilizer being adjustable relative to the drill bit and the steering component. In use, the position of the fulcrum can be adjusted to vary the maximum curvature of the borehole and to suit the rock type(s) being drilled.

Abstract: This invention relates to a steering assembly and to a steering component, suitable for use in drilling operations for oil and gas. The steering assembly comprises a downhole motor which can rotate the drill bit, and a steering component. The steering component has a shaft and a set of elements for engaging the borehole in use. The shaft has a longitudinal axis. The set of elements has a centerline and is movable relative to the shaft between a first position in which the centerline is offset from the longitudinal axis of the shaft by a first distance, and a second position in which the centerline is offset from the longitudinal axis of the shaft by a second distance. In use in drilling operations, movement of the set of elements from the first position to the second position alters the degree of curvature of the drilled hole.

Abstract: A hydraulically powered tractor adapted for advancement through a borehole including an elongate body, aft and forward gripper assemblies, and a valve control assembly housed within the elongate body. The aft and forward gripper assemblies are adapted for selective engagement with the inner surface of the borehole. The valve control assembly includes a gripper control valve for directing pressurized fluid to the aft and forward gripper assemblies. The valve control assembly also includes a propulsion control valve for directing fluid to an aft or forward power chamber for advancing the body relative to the actuated gripper assembly. Aft and forward mechanically actuated valves may be provided for controlling the position of the gripper control valve by detecting and signaling when the body has completed an advancement stroke relative to an actuated gripper assembly.

Abstract: In one aspect of the present invention, a stabilizer assembly on a downhole tool string component, comprising a sleeve slideably attached to a mandrel of the tool string component. At least one stabilizer blade is formed in the sleeve and generally follows the length of the sleeve. A gap is formed in the at least one blade separating a first and second portion of the blade.

Abstract: A system for drilling a lateral hole departing from a main well. The system comprises a motor assembly (415) including a motor (412) to generate a rotating torque, an axial thruster (411) to generate an axial force, a blocking system (410) to fix the motor and the axial thruster downhole. The motor assembly further includes a drive shaft (414) to transmit the rotating torque. The system further comprises a first and second connector (402, 404) for transmitting the rotating torque and the axial force from the motor assembly to a drill string assembly. The first connector is connectable to the drill string assembly so as to transmit the axial force only to the drill pipe (401), and to transmit the rotating torque to a further drive (405) shaft positioned within the drill pipe. The second connector (402) is connectable to the drill string assembly so as to transmit both the axial force and the rotating torque to the drill pipe (401).

Abstract: This invention relates to a steerable drill bit arrangement, in particular for the use in drilling boreholes for oil and gas extraction. There is provided a steerable drill bit arrangement in which the drill bit (20) is connected to a drill string (16) including a steering component (12) and a stabiliser (14), the stabiliser (14) being located between the steering component (12) and the drill bit (20), the steering component (12) being adapted to move the drill string (16) transversely relative to a borehole in which it is located, the stabiliser (14) having an inner part (32) adapted to rotate with the drill string (16) and an outer part (34) adapted to engage the borehole wall, the outer part (34) being rotatable relative to the inner part so that the outer part (34) can remain substantially stationary as the remainder of the stabiliser (14) rotates with the drill string (16).