Abstract: A downhole rotational rate control apparatus, adapted for coupling to the lower end of a drill string, includes a progressive cavity (PC) motor, a driveshaft, a mud flow control valve, and an electronics section. Drilling mud flowing downward through the drill string is partially diverted to flow upward through the PC motor and out into the wellbore annulus, with the mud flow rate and, in turn, the PC motor speed being controlled by the mud flow control valve. The control valve is actuated by a control motor in response to inputs from a sensor assembly in the electronics section. The PC motor drives the driveshaft and a controlled downhole device at a specific zero or non-zero rotational rate. By varying the rotational rate of the PC motor relative to the rotational rate of the drill string, the tool face orientation or non-zero rotational speed of the controlled device in either direction can be varied in a controlled manner.

Abstract: A tubular threaded connection includes a threaded sub-assembly having a first tubular member, a first torque member threadingly received on the first tubular member, and a second torque member threadingly received on the first tubular member. In forming the threaded sub-assembly, the first torque member is torqued relative to the second torque member. Furthermore, the sub-assembly is configured to receive a second tubular member for torqueing against the sub-assembly.

Abstract: A downhole rotational rate control apparatus is disclosed, adapted for coupling to the lower end of a drill string, and includes a progressive cavity (PC) pump or motor, multiple fluid flow paths, and a flow control valve for controlling fluid flow in the flow paths. Drilling mud flowing downward through the drill string is partially diverted to flow through the PC pump or motor and, in turn, the PC pump or motor speed is controlled by the flow control valve. The control valve can be actuated by a control motor in response to inputs from a sensor assembly in an electronics section. The PC pump or motor drives a controlled downhole device at a specific zero or non-zero rotational rate. By varying the rotational rate of the PC pump or motor relative to the rotational rate of the drill string, the tool face orientation or non-zero rotational speed of the controlled device in either direction can be varied in a controlled manner.

Abstract: A rotary fluid drive has first and second bodies 20, 120. The second body 120 is rotatable relative to and inside of the first body 20 defining a working fluid space 40 there between. Gates 130 are supported by the first body 20 and lobes 124 are provide on the second body 120. Gate pockets 26 are formed in the first body 20 into which the gates swing when contacted by the lobes 124. The gates 130 and the gate pockets 26 are configured to form a debris chamber 27 there between capable of temporarily accommodating solid debris. Each gate 130 has a plurality of projections 136A with intervening gaps 136B. The gaps form a gate pocket flow path 141. Working fluid flows via each gate pocket flow path 141 into the working fluid space 40 when the associated gate 130 is maximally deflected into its associated gate pocket 26.

Abstract: A downhole motor rotary drive system including a housing, a rotor rotatably and coaxially disposed within the housing, and an annular space between the rotor and housing. The rotor includes first and second ends, a bore extending between the first and second ends, an inlet port extending from the bore to the annular space, and an outlet port extending from the annular space to the bore. A plurality of gates are disposed within the annular space, each configured to engage the rotor and the housing, and a plurality of lobes extend within the annular space such that the lobes and the gates divide the annular space into a plurality of chambers. A flow path is defined by the annular space between the inlet and outlet ports, and the rotor is configured to rotate relative to the housing when a fluid is circulated along the flow path.

Abstract: A driveshaft assembly for a downhole motor including a driveshaft having a longitudinal axis, first and second ends, and a convex spherical bearing surface disposed at the first end configured to transfer axial loads. The assembly also includes a connection lug disposed at the driveshaft first end, extending circumferentially between first and second ends, and including a recess in the first end of the lug, the recess comprising a concave cylindrical surface concentrically disposed about a pivot axis oriented orthogonal to the longitudinal axis. The assembly also includes a torque transfer key disposed within the recess and having a central axis radially spaced from the pivot axis, a convex cylindrical surface concentrically disposed about the pivot axis, and a planar surface. The convex cylindrical surface of the key slidingly engages the concave cylindrical surface of the recess; and the pivot axis intersects the key.

Abstract: A downhole circulation sub or valve includes a tubular housing with an outer port and a valve piston slidably disposed in the housing. A primary fluid flow path extends through an inner flow bore of the housing and valve piston. In a first position, the valve piston isolates the outer port to prevent fluid communication between the inner flow bore and a well bore annulus. In a second position, the valve piston is moved to obstruct the inner flow bore and expose the outer port to the inner flow bore and allow fluid communication between the inner flow bore and the well bore annulus. An indexing mechanism is coupled between the housing and the valve piston to guide the valve piston between the first and second positions. The indexing mechanism may include a rotatable component.

Abstract: In a mud-lubricated bearing assembly for a downhole motor, a mechanical seal is provided between the mandrel and the lower end of the bearing housing to prevent discharge of drilling fluid (mud) from the bearing assembly into the wellbore annulus. The mechanical seal is effected by mating wear-resistant annular contact surfaces provided on the mandrel and the bearing housing, with biasing means preferably being provided to keep the contact surfaces in sealing engagement during both on-bottom and off-bottom operational modes. The diverted drilling fluid passing through the bearings is redirected into the bore of the mandrel via ports through the mandrel wall to rejoin the main flow to the drill bit, such that substantially all of the drilling fluid flows through the bit.

Abstract: In a mud-lubricated bearing assembly for a downhole motor, a mechanical seal is provided between the mandrel and the lower end of the bearing housing to prevent discharge of drilling fluid (mud) from the bearing assembly into the wellbore annulus. The mechanical seal is effected by mating wear-resistant annular contact surfaces provided on the mandrel and the bearing housing, with biasing means preferably being provided to keep the contact surfaces in sealing engagement during both on-bottom and off-bottom operational modes. The diverted drilling fluid passing through the bearings is redirected into the bore of the mandrel via ports through the mandrel wall to rejoin the main flow to the drill bit, such that substantially all of the drilling fluid flows through the bit.

Abstract: A mechanism for adjusting the relative angular orientation between two coaxial components includes a housing, a mandrel disposed in the housing, a lower ratchet member disposed around the mandrel, wherein a lower engagement interface between the lower ratchet member and the mandrel restricts relative rotation between the lower ratchet member and the mandrel, an upper ratchet member disposed around the mandrel, wherein an upper engagement interface between the upper ratchet member and the mandrel restricts relative rotation between the upper ratchet member and the mandrel, and a central sleeve disposed around the mandrel, wherein an outer engagement interface between the central sleeve and the housing restricts relative rotation between the central sleeve and the housing, wherein the central sleeve has an upper position configured to transmit torque between the upper ratchet member and the housing and a lower position configured to transfer torque between the lower ratchet member and housing.

Abstract: An adjustable bent housing includes a tubular member with a first engagement means and an adjustment ring with a second engagement means. The first engagement means has a plurality of sockets in a first region of the annular end face of the tubular member, and a plurality of locking pins projecting from a second region of the end face. The second engagement means has a plurality of sockets in an annular end face of the adjustment ring, configured to receive the locking pins. The second engagement means further includes an indexing pin projecting from the adjustment ring end face, and receivable within any socket of the first engagement means when the locking pins are disposed within corresponding sockets of the second engagement means. The adjustment ring is longitudinally movable relative to the tubular member to permit relative rotational adjustment therebetween and configured to prevent over-rotation of the adjustment ring.

Abstract: A mechanism for adjusting the relative angular orientation of two coaxial components includes a mandrel having a cylindrical central section between upper and lower splined sections, a sleeve rotatably and slidably disposed around the mandrel's central section, and generally cylindrical upper and lower ratchet members positioned, respectively, about the mandrel's upper and lower splined sections. The ratchet members have internal grooves which receive the mandrel splines for torsional load transfer while permitting limited rotation relative to the mandrel, but their axial positions relative to the mandrel are fixed. The upper and lower ends of the sleeve have circumferentially-arrayed ratchet teeth engageable, respectively, with corresponding teeth on the upper and lower ratchet members. The central sleeve has torque-transferring external splines slidable within matching grooves on the inner surface of a cylindrical tool housing enclosing the mechanism.

Abstract: Apparatus and method for increasing the torque capacity of threaded connections between tubular members. The apparatus may include a first tubular end coupled with a second tubular end, and a torque member wherein the torque member is torqued against the second tubular member and wherein tapered surfaces are engaged between the torque member and the first tubular member at a tapered surface interface.

Abstract: An adjustable bent housing includes a tubular member with a first engagement means and an adjustment ring with a second engagement means. The first engagement means has a plurality of sockets in a first region of the annular end face of the tubular member, and a plurality of locking pins projecting from a second region of the end face. The second engagement means has a plurality of sockets in an annular end face of the adjustment ring, configured to receive the locking pins. The second engagement means further includes an indexing pin projecting from the adjustment ring end face, and receivable within any socket of the first engagement means when the locking pins are disposed within corresponding sockets of the second engagement means. The adjustment ring is longitudinally movable relative to the tubular member to permit relative rotational adjustment therebetween and configured to prevent over-rotation of the adjustment ring.

Abstract: A mechanism for adjusting the relative angular orientation of two coaxial components includes a mandrel having a cylindrical central section between upper and lower splined sections, a sleeve rotatably and slidably disposed around the mandrel's central section, and generally cylindrical upper and lower ratchet members positioned, respectively, about the mandrel's upper and lower splined sections. The ratchet members have internal grooves which receive the mandrel splines for torsional load transfer while permitting limited rotation relative to the mandrel, but their axial positions relative to the mandrel are fixed. The upper and lower ends of the sleeve have circumferentially-arrayed ratchet teeth engageable, respectively, with corresponding teeth on the upper and lower ratchet members. The central sleeve has torque-transferring external splines slidable within matching grooves on the inner surface of a cylindrical tool housing enclosing the mechanism.

Abstract: A downhole rotational rate control apparatus, adapted for coupling to the lower end of a drill string, includes a progressive cavity (PC) motor, a driveshaft, a mud flow control valve, and an electronics section. Drilling mud flowing downward through the drill string is partially diverted to flow upward through the PC motor and out into the wellbore annulus, with the mud flow rate and, in turn, the PC motor speed being controlled by the mud flow control valve. The control valve is actuated by a control motor in response to inputs from a sensor assembly in the electronics section. The PC motor drives the driveshaft and a controlled downhole device at a specific zero or non-zero rotational rate. By varying the rotational rate of the PC motor relative to the rotational rate of the drill string, the tool face orientation or non-zero rotational speed of the controlled device in either direction can be varied in a controlled manner.

Abstract: A driveshaft assembly for a downhole motor comprises a housing and a driveshaft rotatably disposed within the housing. The driveshaft has a central axis and a first end. Further, the driveshaft assembly comprises a driveshaft adapter having a first end coupled to the first end of the driveshaft with a universal joint. The first end of the driveshaft adapter includes a counterbore. The first end of the driveshaft and the universal joint are disposed in the counterbore. Still further, the driveshaft assembly comprises an end cap disposed about the driveshaft and coaxially coupled to the adapter. Moreover, the driveshaft assembly comprises a seal boot disposed about the driveshaft and adapted to restrict fluid flow through a annular gap positioned between the driveshaft and the end cap. The driveshaft assembly also comprises a locking assembly adapted to restrict the end cap from moving axially relative to the adapter.

Abstract: A downhole circulation sub or valve (105) includes a tubular housing with an outer port (140) and a valve piston (170) slidably disposed in the housing. A primary fluid flow path (130) extends through an inner flow bore of the housing and valve piston. In a first position, the valve piston isolates the outer port to prevent fluid communication between the inner flow bore and a well bore annulus. In a second position, the valve piston is moved to obstruct the inner flow bore and expose the outer port to the inner flow bore and allow fluid communication between the inner flow bore and the well bore annulus. An indexing mechanism (165) is coupled between the housing and the valve piston to guide the valve piston between the first and second positions. In some embodiments, the indexing mechanism includes a rotatable component (175).