Abstract: A driveshaft assembly includes a driveshaft including a longitudinal shaft axis, a first end, a second end, and a radially outer surface. The first end includes a plurality of recesses extending radially inward from the radially outer surface. The recesses each include a convex engagement surface. The driveshaft assembly also includes a first end housing including a longitudinal housing axis and an axially extending receptacle. The receptacle includes a plurality of planar receptacle surfaces. In addition, the driveshaft assembly includes a plurality of torque transfer keys configured to transfer torque between the driveshaft and first end housing. Each of the torque transfer keys includes a planar key surface and a concave key surface. The convex engagement surface of each recess engages the concave key surface of one of the torque transfer keys. The planar key surface of each torque transfer key engages one of the planar receptacle surfaces.

Abstract: A downhole motor for directional drilling includes a driveshaft assembly including a driveshaft housing and a driveshaft rotatably disposed within the driveshaft housing. In addition, the downhole motor includes a bearing assembly including a bearing housing and a bearing mandrel rotatably disposed within the bearing housing. The bearing mandrel has a first end directly connected to the driveshaft with a universal joint and a second end coupled to a drill bit. Further, the downhole motor includes an adjustment mandrel configured to adjust an acute deflection angle ? between the central axis of the bearing housing and the central axis of the driveshaft housing. The adjustment mandrel has a central axis coaxially aligned with the bearing housing, a first end coupled to the driveshaft housing, and a second end coupled to the bearing housing.

Abstract: A lubrication system includes a pair of mating surfaces subject to relative motion and a source of lubrication in communication with the mating surfaces. A microfluidic channel system including at least one diffuser element is disposed in an interface between the mating surfaces to create a coherent fluid film at the interface in response to the relative motion.

Abstract: A bend adjustment assembly for a downhole mud motor includes a driveshaft housing, a driveshaft disposed in the driveshaft housing, a bearing mandrel, wherein the bend adjustment assembly includes a first position that provides a first deflection angle between a longitudinal axis of the driveshaft housing and a longitudinal axis of the bearing mandrel, wherein the bend adjustment assembly includes a second position that provides a second deflection angle between the longitudinal axis of the driveshaft housing and the longitudinal axis of the bearing mandrel, and an actuator assembly configured to shift the bend adjustment assembly between the first position and the second position in response to a change in at least one of flowrate of a drilling fluid supplied to the downhole mud motor, pressure of the drilling fluid supplied to the downhole mud motor, and relative rotation between the driveshaft housing and the bearing mandrel.

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 concentric rotary fluid machine includes a first body and a second body that are rotatable relative to each other and coaxially arranged one inside the other. A plurality of gates are supported by the second body in gate pockets. Each gate pocket includes: a gate retention recess that receives a gate cylinder of a gate; a gate seal recess that receives a sealing portion of a gate; and an intervening land. The sealing portion is configured to reciprocate up and down within a corresponding gate seal recess while maintaining contact with the recess and the second body. A plurality of lobes on the first body cause the gates to swing about respective swing axes as the first body rotates relative to the second body. The lobes and the lands are configured so that a lobe forms a substantial seal against a land when in mutual radial alignment.

Abstract: A thread profile for rotary shouldered threaded connections uses different thread root radii for the pin thread and the box thread in order to optimize stress distribution and maximize thread contact area. The thread profile may be adapted for use in double-shouldered, two-start, taper-threaded connections to replace currently-used threaded connections such as the rotor-to-adapter connection in a downhole motor. The thread profile may incorporate an undercut buttress design.

Abstract: A downhole rotational rate control apparatus, adapted for coupling to the lower end of a drill string, includes a progressive cavity pump or motor, a mud flow control valve, and an electronics section. Drilling mud flowing downward through the drill string is partially diverted to flow through the pump or motor, with the mud flow rate and, in turn, the pump or 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. By varying the rotational rate of the 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: 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: 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 includes a driveshaft with a shaft axis, a first end, and a radially outer surface. The first end includes a plurality of recesses extending radially inward from the radially outer surface and each including an engagement surface. The driveshaft assembly also includes an end housing with a receptacle including a plurality of planar receptacle surfaces. Further, the driveshaft assembly includes a torque transfer assembly including a plurality of torque transfer keys each with a planar key surface and a convex key surface, and an adapter including a plurality of concave adapter surfaces and a plurality of planar adapter surfaces. The engagement surface of the each recess engages the planar key surface of one of the keys. The convex key surface of each key engages one of the concave adapter surfaces. Each of the planar adapter surfaces of the adapter engage with one of the receptacle surfaces.

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 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 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 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: A downhole motor for directional drilling includes a driveshaft assembly including a driveshaft housing and a driveshaft rotatably disposed within the driveshaft housing. In addition, the downhole motor includes a bearing assembly including a bearing housing and a bearing mandrel rotatably disposed within the bearing housing. The bearing mandrel has a first end directly connected to the driveshaft with a universal joint and a second end coupled to a drill bit. Further, the downhole motor includes an adjustment mandrel configured to adjust an acute deflection angle ? between the central axis of the bearing housing and the central axis of the driveshaft housing. The adjustment mandrel has a central axis coaxially aligned with the bearing housing, a first end coupled to the driveshaft housing, and a second end coupled to the bearing housing.

Abstract: A concentric rotary fluid machine includes a first body and a second body that are rotatable relative to each other and coaxially arranged one inside the other. A plurality of gates are supported by the second body in gate pockets. Each gate pocket includes: a gate retention recess that receives a gate cylinder of a gate; a gate seal recess that receives a sealing portion of a gate; and an intervening land. The sealing portion is configured to reciprocate up and down within a corresponding gate seal recess while maintaining contact with the recess and the second body. A plurality of lobes on the first body cause the gates to swing about respective swing axes as the first body rotates relative to the second body. The lobes and the lands are configured so that a lobe forms a substantial seal against a land when in mutual radial alignment.

Abstract: A downhole motor for directional drilling includes a driveshaft assembly including a driveshaft housing and a driveshaft rotatably disposed within the driveshaft housing. In addition, the downhole motor includes a bearing assembly including a bearing housing and a bearing mandrel rotatably disposed within the bearing housing. The bearing mandrel has a first end directly connected to the driveshaft with a universal joint and a second end coupled to a drill bit. Further, the downhole motor includes an adjustment mandrel configured to adjust an acute deflection angle ? between the central axis of the bearing housing and the central axis of the driveshaft housing. The adjustment mandrel has a central axis coaxially aligned with the bearing housing, a first end coupled to the driveshaft housing, and a second end coupled to the bearing housing.

Abstract: A downhole rotational rate control apparatus, adapted for coupling to the lower end of a drill string, includes a progressive cavity pump or motor, a mud flow control valve, and an electronics section. Drilling mud flowing downward through the drill string is partially diverted to flow through the pump or motor, with the mud flow rate and, in turn, the pump or 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. By varying the rotational rate of the 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: 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.