A drill bit assembly for fluid-operated percussion drill tools. The assembly comprises a percussion bit comprising a bit head detachably connected to an axially extending shank and engagement means formed on an external wall of the shank engageable with complementary engagement means formed internally of a drive chuck whereby rotational drive from the chuck may be transmitted to the shank. At least one flushing channel extends between the external wall of the bit shank and a cutting face of the bit head, to provide a fluid path for a flushing medium between the external wall of the bit shank and the cutting face of the bit head.

A radial bearing apparatus including a housing with a housing bore defining a radial bearing housing surface, a shaft extending through the housing bore and defining a radial bearing shaft surface, and a radial bearing contact interface between the radial bearing housing surface and the radial bearing shaft surface for bearing a variable side force applied to the shaft. The radial bearing contact interface includes an oblique section in which the radial bearing housing surface and the radial bearing shaft surface are oblique to each other when the side force is zero and progressively increase in contact in an axial direction in response to an increasing magnitude of the side force.

A coating architecture is disclosed that includes a substrate having a surface finish R.sub.a of 0.3μ or finer, an intermediate layer overlying and in contact with the substrate; and a solid lubricant layer overlying and in contact with the intermediate layer. The test results of applying the coating architecture to a reciprocating hammer drill utilizing the coating is also disclosed.

A downhole drilling motor includes a motor housing having an inner bore and an outer surface. A power section includes a stator elastomer at least partially disposed within the inner bore of the motor housing. A bearing section includes an upper bearing at least partially disposed within the inner bore of the motor housing. The motor housing further includes an opening extending from the inner bore to the outer surface to provide a bypass fluid path for a fluid in the inner bore. The opening is disposed on the motor housing between a lower end of the stator elastomer and an upper end of the upper bearing. The bypass fluid path allows the downhole drilling motor to accommodate a higher flow rate of a fluid through the stator elastomer of the power section than through the upper bearing of the bearing section.

Systems are provided comprising at least one driving cylinder comprising a driving chamber and a driving piston within the driving chamber. The driving piston separates the driving chamber into a driving fluid zone for receiving a driving fluid and a buffer zone for receiving a buffer fluid. The driving piston is movable in the driving chamber by the driving fluid. The systems may also comprise a driven cylinder comprising a driven chamber and a driven piston moveable in the driven chamber. The driven piston is connected to and driven by the driving piston to move within the driven chamber. The driven chamber comprises an input port configured to receive a driven fluid at a first, lower pressure into the driven chamber and an output port configured to expel the driven fluid at a second, higher pressure from the driven chamber when the driven fluid is pressurized by the driven piston. The buffer fluid is different from the driving fluid and the driven fluid, and the buffer fluid in the buffer zone separates the driving fluid from the driven fluid.

There is provided a wrench for a workpiece having a wrench head with a fixed jaw element and an adjustable jaw element opposite the fixed jaw element, the fixed jaw element and the adjustable jaw element defining a workpiece engagement area that receives and engages the workpiece. The fixed jaw element and the adjustable jaw element are connected by a pin and slot connection that permits movement of the adjustable jaw element relative to the fixed jaw element to adjust the size of the workpiece engagement area. A removable die is provided that engages the slot to restrict the movement of the pin along the slot and define a maximum size of the workpiece engagement area. An articulated actuator actuates the wrench head to apply torque to the workpiece.

There is provided a wrench for a workpiece having a wrench head with a fixed jaw element and an adjustable jaw element opposite the fixed jaw element, the fixed jaw element and the adjustable jaw element defining a workpiece engagement area that receives and engages the workpiece. The fixed jaw element and the adjustable jaw element are connected by a pin and slot connection that permits movement of the adjustable jaw element relative to the fixed jaw element to adjust the size of the workpiece engagement area. A removable die is provided that engages the slot to restrict the movement of the pin along the slot and define a maximum size of the workpiece engagement area. An articulated actuator actuates the wrench head to apply torque to the workpiece.

A harmonic drive assembly and fluid-powered linear motors with both axial pistons are rotary piston arrangements incorporating the harmonic drive assembly are disclosed. The motors may be used in downhole drilling applications, but the drive assembly and/or motors may be used in other applications. The assembly, motors and methods use advanced harmonic drives, advanced helical drives, and combinations thereof with 1) motors with axial pistons and reciprocating linear rings to convert reciprocative axial motion to continuous rotary motion, and 2) motors with rotary pistons and reciprocating linear rings to rectify reciprocative rotary motion to continual rotary motion to improve performance over prior configurations.

The present disclosure provides a system for improving wear resistance of a downhole tool component using a bonded diamond compact (BDC) construct. The BDC construct includes a BDC element and an encapsulation layer bonded to the BDC element. The encapsulation layer may fully encapsulate the BDC element. The downhole tool component may be a drill bit, push the bit pad, or mud motor beating assembly. The BDC construct may be disposed in a plug section of the downhole tool component. The encapsulation layer may form an insulating layer over the BDC element to protect the BDC element from thermal damage during hard-facing or brazing of the BDC construct to the downhole tool component.

This disclosure describes various implementations of a downhole-blower system that can be used to boost production in a wellbore. The downhole-blower system includes a blower and an electric machine coupled to the blower that can be deployed in a wellbore, and that can, in cooperation, increase production through the wellbore.