A mud motor, system, and method for using same are disclosed. A mud motor can include a continuously formed power section stator housing having a first end, a second end, and an internal cavity comprising a series of stator lobes and a housing portion passing. The stator lobes can extend from the first end of the power section stator housing until a first end of a transition portion. The transition portion can form a unitary combination with the stator lobes. The mud motor further includes a rotor assembly including a power section rotor having rotor lobes to be disposed completely within the internal cavity. Additional apparatuses, systems, and methods are disclosed.

A drilling system for drilling a wellbore using drilling fluid includes a drillstring, a drill bit coupled to the drillstring, and a mud motor coupled to the drillstring and operable to rotate the drill bit by rotating a driveshaft with a bore. The drilling system also includes a bearing assembly that includes a bypass fluid flowpath through the bearings for drilling fluid to divert from the bore. A choke assembly positioned in the bypass fluid flowpath restricts flow of the diverted drilling fluid such that some diverted drilling fluid flows into an annulus in the wellbore outside of the bearing assembly through an unsealed annulus port and some of diverted drilling fluid is recaptured through a return flowline. The drilling system also includes a rotary steerable system operable to push the drill bit in a desired direction using pads extendable with the drilling fluid.

A bearing element for a bearing assembly has a body of polycrystalline diamond (PCD) material having a bearing contact surface, and a substrate bonded to the body of PCD material along an interface and having a free end surface. The substrate has a through-bore extending longitudinally therethrough, the body of PCD material having a portion extending through the through-bore in the substrate to at least the free end surface thereof, the substrate extending around the peripheral side edge of the portion of PCD material extending therethrough.

Methods for manufacturing bearings and wear resistant surfaces usable in various downhole tools are described herein. A housing is provided. A laser configured for insertion into the housing, such as an inner diameter laser, is used to connect a fusible material to the inner surface of the housing or an insert disposed therein to form a hard facing layer on the inner surface. Simultaneously or independently, the laser can be used to connect the fusible material to the outer surface of a mandrel within the housing to form a second hard facing layer. The present methods thereby produce durable radial bearings having extended operational life, which can be produced within a bearing housing, or externally for transport and installation in existing bearing housings.

A longer-lasting, lower cost, more powerful, all metal, mud motor than the presently available progressing cavity type mud motors for drilling boreholes into the earth. A mud motor apparatus possessing one single drive shaft that turns a rotary drill bit, which apparatus is attached to a drill pipe which provides high pressure mud to the mud motor, wherein the drive shaft receives at least a first portion of its rotational torque from any high pressure mud flowing through a first hydraulic chamber within the apparatus, and receives at least a second portion of its rotational torque from any high pressure mud flowing through a second hydraulic chamber within the apparatus. A typical mud motor apparatus possesses two or more hydraulic chambers, each having its own power stroke, and return stroke, which act together in a controlled fashion to provide continuous power to a rotary drill bit.

A motor rotary steerable system having a sun gear shaft, a pair of planetary gears rotated by the sun gear shaft, an adjustable slip clutch assembly rotated by the planetary gears in an opposite direction, and an orienting device connected to the planetary gears and adjustable slip clutch assembly. The orienting device comprises a bent sub with a bent sub housing, a bearing section, a bit drive assembly, a pulse counter to count the rotating drive shaft rotations, a drilling bit locator, and a transmitting device conveying signals from the orienting device to a receiver in an opposite side of a power section. The orienting device rotates independently from a drill string and is synchronously timed to the rotation of the drill string to rotate continuously while producing both straight and curved bore path segments and increase production rates.

A motor rotary steerable system having a sun gear shaft, a pair of planetary gears rotated by the sun gear shaft, an adjustable slip clutch assembly rotated by the planetary gears in an opposite direction, and an orienting device connected to the planetary gears and adjustable slip clutch assembly. The orienting device comprises a bent sub with a bent sub housing, a bearing section, a bit drive assembly, a pulse counter to count the rotating drive shaft rotations, a drilling bit locator, and a transmitting device conveying signals from the orienting device to a receiver in an opposite side of a power section. The orienting device rotates independently from a drill string and is synchronously timed to the rotation of the drill string to rotate continuously while producing both straight and curved bore path segments and increase production rates.

A self propelling vehicle capable of propagating through a solid medium, comprising two or more rotors, arranged in tandem, and means for rotating the rotors, each rotor being formed as a hollow rotational body with an external helicoidal flighting, configured to engage surrounding solid medium, wherein the flightings of any pair of adjacent rotors follow helicoids of mutually opposite senses and the means for rotating are operative to rotate the adjacent rotors in mutually opposite senses.

A self propelling vehicle capable of propagating through a solid medium, comprising two or more rotors, arranged in tandem, and means for rotating the rotors, each rotor being formed as a hollow rotational body with an external helicoidal flighting, configured to engage surrounding solid medium, wherein the flightings of any pair of adjacent rotors follow helicoids of mutually opposite senses and the means for rotating are operative to rotate the adjacent rotors in mutually opposite senses.

A device in respect of a hydraulic rock drilling machine (1) with a machine housing (2,3,11), which encloses a hydraulic percussion device, a rotation mechanism (4) for rotation driving a shank adapter (1) and a guiding device (6) for the shank adapter, wherein the rock drilling machine includes at least one supply channel for lubricant to said components intended for lubrication, and at least one outlet channel (5,7) for used lubricant. Said at least one outlet channel (5,7) is connected to a separation chamber (8) for separating particle-shaped impurities existing in used lubricant. The separation chamber (8) has a discharge conduit (9) for treated lubricant. The invention also concerns a method and a rock drilling machine.