Embodiments of the invention are directed to bearing assemblies configured to effectively carry nonuniform loads, bearing apparatuses including such bearing assemblies, and methods of operating such bearing assemblies and apparatuses. In an embodiment, under some operational conditions, one or more portions of the bearing assemblies and bearing apparatus may be preferentially loaded, such as to carry preferentially higher loads (e.g., radial and/or axial loads) than other portion(s) of the bearing assemblies and bearing apparatus.

Embodiments of the invention are directed to bearing assemblies configured to effectively provide heat dissipation for bearing elements, bearing apparatuses including such bearing assemblies, and methods of operating such bearing assemblies and apparatuses. In an embodiment, a bearing assembly includes a plurality of superhard bearing elements distributed about an axis. Each superhard bearing element of the plurality of superhard bearing elements has a superhard table including a superhard surface. The bearing assembly includes a support ring structure coupled to the plurality of superhard bearing elements. One or more of the superhard bearing elements includes a superhard table, which may improve heat transfer from such superhard bearing elements.

Embodiments disclosed herein are directed to bearing assemblies that include integrated lubrication, bearing apparatuses including such bearing assemblies, and related methods. For example, a lubricated bearing assembly may include a lubricant that may lubricate the bearing surface thereof during operation of the lubricated bearing assembly and/or bearing apparatus including the lubricated bearing assembly.

Embodiments of the invention relate to bearing apparatuses in which one bearing surface of the bearing apparatus includes diamond, while another bearing surface includes a non-diamond superhard material (e.g., silicon carbide). For example, a bearing apparatus may include a bearing stator assembly and a bearing rotor assembly. The bearing stator assembly and bearing rotor assembly each include a support ring and one or more superhard bearing elements generally opposed to one another. The bearing surface(s) of the rotor or stator may include diamond, while the bearing surface(s) of the other of the rotor or stator do not include diamond. Another bearing apparatus may include both thrust- and radial bearing components. The generally opposed thrust-bearing elements may include diamond, while the generally opposed radial bearing elements may not include diamond, but include a non-diamond superhard material, such as silicon carbide.

Embodiments of the invention relate to tilting pad bearing assemblies and apparatuses. The disclosed tilting pad bearing assemblies and apparatuses may be employed in downhole motors of a subterranean drilling system or other mechanical systems. In an embodiment, a bearing assembly or apparatus includes a support ring and a plurality of tilting pads. Each tilting pad is tilted and/or tiltably secured relative to the support ring. In some embodiments, one or more of the tilting pads include a plurality of superhard bearing segments assembled to form a superhard bearing surface. One or more seams may be positioned between adjacent superhard bearing segments of the superhard bearing segments. In other embodiments, one or more of the tilting pads may include at least one or only one superhard bearing segment, such as a polycrystalline diamond bearing segment.

The present invention relates to a downhole tool, comprising a hydraulic assembly, an arm assembly, the arm assembly comprising a wheel, a hydraulic motor for rotating the wheel, thereby driving the downhole tool in a forward direction, and a hydraulic pump unit for simultaneous generation of a first and a second pressurized fluid, characterized in that the arm assembly is movable between a retracted position and a projecting position in relation to the tool housing, and the downhole tool furthermore comprises an arm activation assembly for moving the arm assembly between the retracted position and the projecting position, and the hydraulic motor drives the downhole tool in the forward direction when the arm assembly is in the projecting position, the arm activation assembly being in fluid connection with the first pressurized fluid and the hydraulic motor being in fluid connection with the second pressurized fluid, a hydraulic control block for controlling the pressure of the first pressurized fluid having a first pressure and controlling a second pressure of the second pressurized fluid, and a hydraulic control block comprising a first sequential valve for controlling a sequence of retraction of the arm assembly, a projection of the arm assembly and a rotation of the wheel, wherein the sequential valve is fluidly connected with one of the fluids and changes between an open and a closed position based upon the pressure of the other fluid. Furthermore, the present invention relates to a method of controlling a projection of an arm assembly of a driving unit of a downhole tool and to a downhole system.

A downhole steering tool includes one or more steering blades selectively extendable from a housing. Each steering blade may be extended by fluid pressure within a steering cylinder. Each steering cylinder may be coupled to the interior of a mandrel positioned within the housing through an adjustable orifice. The adjustable orifice may be moved between an open and a partially open position. The adjustable orifice may be solenoid controlled or controlled by a ring valve. The adjustable orifice may generate one or more pressure pulses to transmit data to the surface.

Embodiments of the invention relate to tilting pad bearing assemblies and apparatuses. The disclosed tilting pad bearing assemblies and apparatuses may be employed in downhole motors of a subterranean drilling system or other mechanical systems. In an embodiment, a bearing assembly or apparatus includes a support ring and a plurality of tilting pads. Each tilting pad is tilted and/or tiltably secured relative to the support ring. In some embodiments, one or more of the tilting pads include a plurality of superhard bearing segments assembled to form a superhard bearing surface. One or more seams may be positioned between adjacent superhard bearing segments of the superhard bearing segments. In other embodiments, one or more of the tilting pads may include at least one or only one superhard bearing segment, such as a polycrystalline diamond bearing segment.

Embodiments of the invention relate to bearing apparatuses in which one bearing surface of the bearing apparatus includes diamond, while another bearing surface includes a non-diamond superhard material (e.g., silicon carbide). For example, a bearing apparatus may include a bearing stator assembly and a bearing rotor assembly. The bearing stator assembly and bearing rotor assembly each include a support ring and one or more superhard bearing elements generally opposed to one another. The bearing surface(s) of the rotor or stator may include diamond, while the bearing surface(s) of the other of the rotor or stator do not include diamond. Another bearing apparatus may include both thrust- and radial bearing components. The generally opposed thrust-bearing elements may include diamond, while the generally opposed radial bearing elements may not include diamond, but include a non-diamond superhard material, such as silicon carbide.

A setting tool (10) for use in a downhole wellbore is described as having a hydraulic fluid pumping mechanism (78) for providing pressurized hydraulic fluid. A piston mechanism (116) is moveable by said pressurized hydraulic fluid acting upon a portion of the piston mechanism (116). A resetting mechanism (84) is provided which when operated releases the pressurized hydraulic fluid from acting upon said portion of the piston (116) and which results in the resetting of the setting tool (10). In addition, a method for resetting a setting tool (10) is described including the steps of: (i) running the setting tool (10) downhole; (ii) actuating the setting tool (10) and thereby deploying an apparatus (203) downhole; (iii) retrieving the setting tool (10) to surface; and (iv) bleeding off pressure to reset the setting tool (10).