Abstract: This invention relates to a torque control device for a downhole drilling assembly, the torque control device being adapted for connection to a drill bit. The torque control device includes an outer sleeve and an inner shaft, the outer sleeve being movable longitudinally relative to the inner shaft. The torque control device has a cylinder, a piston located within the cylinder, and a rotary valve to control the volume of the cylinder. The volume of the cylinder can be changed by way of the rotary valve whereby to adjust the weight on bit and thereby control the torque upon the drill bit.

Abstract: This invention relates to an articulating component (16) of a downhole assembly, and to a downhole steering assembly. There is provided an articulating component (16) having a first end (40) and a second end (42), the articulating component being adapted to transmit torque between the first end and the second end. The articulating component has a pivotable coupling (46) between its first and second ends and at least one control element for the pivotable coupling, the control element(s) having an active condition in which the pivotable coupling is substantially locked against pivoting movement, and an inactive condition in which the pivotable coupling is unlocked. In a downhole steering assembly the articulating component is located downhole of the steering component whereby to protect the steering component from unwanted vibrations generated downhole, or uphole of the steering component whereby to protect the steering component from unwanted vibrations generated uphole, or both.

Abstract: This invention relates to an apparatus and method for controlling a part of a downhole assembly, and to the downhole assembly. The downhole assembly may include a steering mechanism adapted to steer a drill bit in a chosen direction, and the steering mechanism may be the part of the downhole assembly which is controlled by the apparatus. The downhole assembly includes a drill bit and a motor, the motor having a stator and a rotor, the rotor being driven to rotate relative to the stator by the passage of a drilling fluid along a drilling fluid path between the rotor and the stator. The motor has a conduit through which the drilling fluid can pass, the conduit being separate from the drilling fluid path, and the apparatus has a valve to control the flow of drilling fluid through the conduit. The invention provides a robust and reliable means of delivering high pressure drilling fluid downstream of the motor.

Abstract: This invention relates to a controllable deflection tool. The controllable deflection tool is likely to have its greatest utility as part of a downhole assembly to steer a drill bit during drilling for oil and gas. There is provided a controllable deflection tool having a first end and a second end, the tool having: a conduit for a working fluid; a rotary element adapted for rotation within the tool; a deflection member; a vane motor configured to rotate the deflection member relative to the rotary element; and a valve for controlling the flow of working fluid to the vane motor. There is also provided a downhole steering assembly and a method of steering a downhole drilling assembly incorporating the controllable deflection tool.

Abstract: This invention relates to a torque control device for a downhole drilling assembly, the torque control device being adapted for connection to a drill bit. The torque control device includes an outer sleeve and an inner shaft, the outer sleeve being movable longitudinally relative to the inner shaft. The torque control device has a cylinder, a piston located within the cylinder, and a rotary valve to control the volume of the cylinder. The volume of the cylinder can be changed by way of the rotary valve whereby to adjust the weight on bit and thereby control the torque upon the drill bit.

Abstract: This invention relates to a torque control device for a downhole drilling assembly. The torque control device is adapted for connection to a drill bit, and has an outer sleeve and an inner shaft, the outer sleeve being movable longitudinally relative to the inner shaft. The torque control device also has a cylinder, a piston located within the cylinder, and a controller to control the volume of the cylinder. Changing the volume of the cylinder causes relative longitudinal movement between the outer sleeve and the inner shaft. The controller can receive inputs from a torque sensor and/or an accelerometer in order to determine if a threshold torque has been exceeded. Alternatively the controller can comprise a rotary valve which automatically responds to torque in the assembly.

Abstract: This invention relates to an articulating component (16) of a downhole assembly, and to a downhole steering assembly. There is provided an articulating component (16) having a first end (40) and a second end (42), the articulating component being adapted to transmit torque between the first end and the second end. The articulating component has a pivotable coupling (46) between its first and second ends and at least one control element for the pivotable coupling, the control element(s) having an active condition in which the pivotable coupling is substantially locked against pivoting movement, and an inactive condition in which the pivotable coupling is unlocked. In a downhole steering assembly the articulating component is located downhole of the steering component whereby to protect the steering component from unwanted vibrations generated downhole, or uphole of the steering component whereby to protect the steering component from unwanted vibrations generated uphole, or both.

Abstract: This invention relates to an apparatus and method for controlling a part of a downhole assembly, and to the downhole assembly. The downhole assembly may include a steering mechanism adapted to steer a drill bit in a chosen direction, and the steering mechanism may be the part of the downhole assembly which is controlled by the apparatus. The downhole assembly includes a drill bit and a motor, the motor having a stator and a rotor, the rotor being driven to rotate relative to the stator by the passage of a drilling fluid along a drilling fluid path between the rotor and the stator. The motor has a conduit through which the drilling fluid can pass, the conduit being separate from the drilling fluid path, and the apparatus has a valve to control the flow of drilling fluid through the conduit. The invention provides a robust and reliable means of delivering high pressure drilling fluid downstream of the motor.

Abstract: An intervertebral joint prosthesis having a ball component (22) for engagement with a first vertebra (26) and a trough component (24) for engagement with a second vertebra (27) adjacent to the first vertebra is disclosed. The trough component (24) includes a generally concave surface (50) having a substantially flat portion (52). When the ball component (22) and the trough component (24) are engaged to their respective vertebrae, the ball component (72) and the trough component (24) engage each other, permitting rotation and translation of the vertebrae with respect to each other. Both components include a flange (34, 56) for engaging a vertebra. The invention also contemplates a method for and a tool for use in implanting a two-piece intervertebral joint prosthesis.

Abstract: This invention relates to a steering component, to a steering assembly, and to a method of steering a drill bit in a borehole. The steering component is adapted for connection to a drill string, the drill string carrying a drill bit and a motor for rotating the drill bit. The steering component comprises: a rotatable driveshaft adapted for connection between the drill bit and the motor; a drive mechanism; and an offsetting component; the drive mechanism providing a rotatable connection between the drill string and the offsetting component whereby the drill string can rotate relative to the offsetting component. The drive mechanism is adapted to drive the offsetting component to rotate in an opposed direction to the driveshaft, so as to counter the rotation of the offsetting component which is induced by friction within the componentry as the driveshaft rotates. The steering component and method are likely to have their greatest utility in steering a drill bit during drilling for oil and gas.

Abstract: This invention relates to a controllable deflection tool. The controllable deflection tool is likely to have its greatest utility as part of a downhole assembly to steer a drill bit during drilling for oil and gas. There is provided a controllable deflection tool having a first end and a second end, the tool having: a conduit for a working fluid; a rotary element adapted for rotation within the tool; a deflection member; a vane motor configured to rotate the deflection member relative to the rotary element; and a valve for controlling the flow of working fluid to the vane motor. There is also provided a downhole steering assembly and a method of steering a downhole drilling assembly incorporating the controllable deflection tool.

Abstract: This invention relates to a steering component, to a steering assembly, and to a method of steering a drill bit in a borehole. The steering component is adapted for connection to a drill string, the drill string carrying a drill bit and a motor for rotating the drill bit. The steering component comprises: a rotatable driveshaft adapted for connection between the drill bit and the motor; a drive mechanism; and an offsetting component; the drive mechanism providing a rotatable connection between the drill string and the offsetting component whereby the drill string can rotate relative to the offsetting component. The drive mechanism is adapted to drive the offsetting component to rotate in an opposed direction to the driveshaft, so as to counter the rotation of the offsetting component which is induced by friction within the componentry as the driveshaft rotates. The steering component and method are likely to have their greatest utility in steering a drill bit during drilling for oil and gas.

Abstract: An intervertebral joint prosthesis having a ball component (22) for engagement with a first vertebra (26) and a trough component (24) for engagement with a second vertebra (27) adjacent to the first vertebra is disclosed. The trough component (24) includes a generally concave surface (50) having a substantially flat portion (52). When the ball component (22) and the trough component (24) are engaged to their respective vertebrae, the ball component (72) and the trough component (24) engage each other, permitting rotation and translation of the vertebrae with respect to each other. Both components include a flange (34,56) for engaging a vertebra. The invention also contemplates a method for and a tool for use in implanting a two-piece intervertebral joint prosthesis.

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 downhole assembly and to a cutter assembly, and in particular to a downhole assembly including an apparatus for breaking up large-scale material which is present behind a drill bit, and to a cutter assembly for use in such a downhole assembly. The downhole assembly is suitably for use in a drillstring, the downhole assembly comprising a drill bit, a sensitive component, and at least one rotatable set of cutter blades located between the drill bit and the sensitive component.

Abstract: An assembly and methods for constructing a MONOWELL include a monodiameter casing disposed in a monodiameter wellbore having diametric efficiency with a monobore production delivery system disposed within the monodiameter casing. An assembly for constructing a monodiameter wellbore includes a bottomhole assembly having a overgauge hole drilling member, a directional steering assembly, a measurement while drilling tool, and a logging while drilling tool; a work string attached to the bottomhole assembly and extending to the surface; drilling fluids flowing through the work string and bottomhole assembly; chemical casing casing the borehole; expandable casing disposed in the wellbore; and a sealing composition disposed between the expandable casing and the wellbore.

Abstract: This invention relates to a downhole assembly and to a cutter assembly, and in particular to a downhole assembly including an apparatus for breaking up large-scale material which is present behind a drill bit, and to a cutter assembly for use in such a downhole assembly. The downhole assembly is suitably for use in a drillstring, the downhole assembly comprising a drill bit, a sensitive component, and at least one rotatable set of cutter blades located between the drill bit and the sensitive component.

Abstract: This invention relates to a downhole assembly and to a cutter assembly, and in particular to a downhole assembly including an apparatus for breaking up large-scale material which is present behind a drill bit, and to a cutter assembly for use in such a downhole assembly. The downhole assembly is suitably for use in a drillstring, the downhole assembly comprising a drill bit, a sensitive component, and at least one rotatable set of cutter blades located between the drill bit and the sensitive component.

Abstract: An intervertebral joint prosthesis having a ball component (22) for engagement with a first vertebra (26) and a trough component (24) for engagement with a second vertebra (27) adjacent to the first vertebra is disclosed. The trough component (24) includes a generally concave surface (50) having a substantially flat portion (52). When the ball component (22) and the trough component (24) are engaged to their respective vertebrae, the ball component (72) and the trough component (24) engage each other, permitting rotation and translation of the vertebrae with respect to each other. Both components include a flange (34, 56) for engaging a vertebra. The invention also contemplates a method for and a tool for use in implanting a two-piece intervertebral joint prosthesis.

Abstract: This invention relates to a steering component, to a steering assembly, and to a method of steering a drill bit in a borehole. The steering component is adapted for connection to a drill string, the drill string carrying a drill bit and a motor for rotating the drill bit. The steering component comprises: a rotatable driveshaft adapted for connection between the drill bit and the motor; a drive mechanism; and an offsetting component; the drive mechanism providing a rotatable connection between the drill string and the offsetting component whereby the drill string can rotate relative to the offsetting component. The drive mechanism is adapted to drive the offsetting component to rotate in an opposed direction to the driveshaft, so as to counter the rotation of the offsetting component which is induced by friction within the componentry as the driveshaft rotates. The steering component and method are likely to have their greatest utility in steering a drill bit during drilling for oil and gas.