Abstract:
A down-hole drilling assembly (12, 16) and control system (120) therefor, for directional drilling including a bent housing of a bottom hole assembly (18), utilizing a gearbox (102) to derive a higher speed (about 600 r.p.m.) rotational drive (104) from the drill string (10) to drive a drilling bit (20) via an electromagnetic clutch (110, 112) controlled by the control system (120) such that the clutch balances reaction torque when the orientation angle of the bent housing is correct.
Abstract:
A down-hole drilling assembly (12,16) and control system (120) therefor, for directional drilling including a bent housing of a bottom hole assembly (18), utilising a gearbox (102) to derive a higher speed (about 600 r.p.m.) rotational drive (104) from the drill string (10) to drive a drilling bit (20) via an electromagnetic clutch (110, 112) controlled by the control system (120) such that the clutch balances reaction torque when the orientation angle of the bent housing is correct.
Abstract:
Drilling means for directional drilling in a bore hole comprising a drill pipe and a drilling head, including a slippable clutch device linking the drill pipe and said drilling head such that torque due to rotation of said drill pipe can be controllably applied to said drilling head through at least partial engagement of said clutch, and control means operable to sense an actual orientation angle of said drilling head and compare said actual orientation angle with a required orientation angle adjustably set in said control means and to control said slippable clutch such that when the actual orientation angle and the required orientation angle are the same, the slip torque of the slipping clutch equals the motor reaction torque, so maintaining the orientation angle of the drilling tool at said required orientation angle.
Abstract:
Drilling means for directional drilling in a bore hole comprising a drill pipe and a drilling head, including a slippable clutch device linking the drill pipe and said drilling head such that torque due to rotation of said drill pipe can be controllably applied to said drilling head through at least partial engagement of said clutch, and control means operable to sense an actual orientation angle of said drilling head and compare said actual orientation angle with a required orientation angle adjustably set in said control means and to control said slippable clutch such that when the actual orientation angle and the required orientation angle are the same, the slip torque of the slipping clutch equals the motor reaction torque, so maintaining the orientation angle of the drilling tool at said required orientation angle.
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:
A bottom hole assembly 10 for drilling a deviated borehole includes a positive displacement motor (PDM) 12 or a rotary steerable device (RSD) 110 having a substantially uniform diameter motor housing outer surface without stabilizers extending radially therefrom. In a PDM application, the motor housing 14 may have a fixed bend therein between an upper power section 16 and a lower bearing section 18. The long gauge bit 20 powered by the motor 10 may have a bit face 22 with cutters 28 thereon and a gauge section 24 having a uniform diameter cylindrical surface 26. The gauge section 24 preferably has an axial length at least 75% of the bit diameter. The axial spacing between the bit face and the bend of the motor housing preferably is less than twelve times the bit diameter. According to the method of the present invention, the bit may be rotated at a speed of less than 350 rpm by the PDM and/or rotation of the RSD from the surface.
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:
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 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.