A drive shaft assembly includes a drive shaft that includes a first cylindrical end having a first diameter, a cylindrical portion having a second diameter, and a second cylindrical end having the first diameter. A first distal end of the drive shaft includes a first distal spherical indentation. A first adapter cap includes a first tapered inner aperture and a first seal disposed within a first groove formed in a circumference of the first tapered inner aperture. The first tapered inner aperture is configured to receive the first cylindrical end of the drive shaft and the first seal forms a seal with the cylindrical portion of the drive shaft having the second diameter. A first adapter includes a first distal spherical indentation. A first distal spherical ball is removably attached to the first distal spherical indentation.

A downhole motor (107) which comprises a stator housing (108), a rotor assembly (106) rotatable relative to said stator housing, and an arrangement for enabling, in use, a drill bit connected to the rotor assembly of said downhole motor to be rotated by rotating a drill string connected to said stator housing, wherein said arrangement comprises a unidirectional clutch (117) disposed between said rotor assembly and said stator housing and having at least one pawl which can be displaced between an inoperative position adjacent said stator housing and an operative position in which rotation of said stator housing by said drill string in one sense is transmitted to said rotor assembly via said at least one pawl, means biasing said at least one pawl towards said operative position, means retaining said at least one pawl in its inoperative position, and means which, when sufficient pulling force is applied to said drill string, will cause said means retaining said at least one pawl to release said at least one pawl and enable said at least one pawl to move into its operative position.

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.

The present invention provides a rotary guiding tool, comprising: a power unit having an output shaft capable of outputting a torque and an offset driving portion capable of outputting a radial force and/or an axial force; a transmission shaft connected with the output shaft; a support shaft connected with the transmission shaft through a rotation structure, wherein a rotation axis of the rotation structure is perpendicular to an axis of the output shaft, the support shaft has an inner wall defining an accommodating cavity and a forward end and a rearward end formed at both ends of the accommodating cavity, a rotation center of the rotation structure is located in the accommodating cavity, and the rearward end of the support shaft is capable of being driven by the radial force output by the offset driving portion; and a drill bit having a drill bit tail end, wherein the drill bit and the forward end of the support shaft are connected to the drill bit tail end. According to the present invention, the rotary guiding tool may improve the whipstocking ability of the drilling tool, and reduce the energy consumption of driving the drilling tool.

A method for operating a well tractor is presented. The method involves running a well tractor coupled to a wireline into a wellbore and supplying an amount of electric power to the well tractor to operate the well tractor at a first speed to urge the wireline through the wellbore at a first force. A variable gear ratio transmission of the well tractor is adjusted and an amount of electric power is supplied to the well tractor to operate the well tractor at a second speed different than the first speed to urge the wireline through the wellbore at a second force different than the first force based on adjusting the variable gear ratio transmission.

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. Axial pistons provide a robust simple solution for generating rotation; Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long, a high-torque motor can be produced using this method.

The invention relates to a rotary drive arrangement for a drill rod having an outer pipe and an inner rod running at least in sections inside the outer pipe, in particular for double-head and/or overburden drilling, with a first gearbox for driving the inner rod in a rotating manner and a second gearbox for driving the outer pipe in a rotating manner, wherein the first gearbox and the second gearbox are independent of each other. According to the invention provision is made in that the first gearbox and the second gearbox are supported in a common gearbox housing and are surrounded by the same.

The disclosure belongs to the technical field of engineering construction, and particularly relates to a square pile construction method and equipment of a rotary drilling rig. The specific technical solution concerns a square pile construction method of a rotary drilling rig which includes: site leveling; surveying and setting out; creating concrete retaining wall of wellhead; putting the drilling rig in place; adjusting the verticality of the drilling rig; lead hole drilling; reamed hole drilling; square hole drilling; hole cleaning with round drill bit; and hole cleaning with square drill bit. The square pile construction method and rotary drilling rig can use equipment for square pile construction in the whole process, effectively reduce the underground operation of laborers, and avoid the project safety production risk from the source. The disclosure also provides three kinds of square pile drill bits and a square pile hole cleaning drill bit in cooperation with the square pile construction method, which further realizes the mechanization of the whole process of square pile construction.

A modular anti-rotation device for preventing rotation with respect to the central axis of a drilling tool in a borehole and for producing a notch in a borehole surface. The anti-rotation device includes an upper fixture portion and a lower fixture portion in axial alignment. The upper fixture portion and the lower fixture portion are connected by yoke assemblies. Each yoke assembly is connected to the fixture portion and fixture portion at one end, and forming an articulated joint of the upper yoke assembly and the lower yoke assembly at a distal end opposite the first end. A roller is connected at each joint, connecting the upper and lower yoke assemblies. The rollers engage vertically with a borehole surface, the rollers travelling axially, as a drill shaft penetrates into the borehole, the rollers simultaneously preventing radial movement of the anti-rotation device and prevent rotation with respect to the central axis of the borehole.

An apparatus for transferring torque comprising a pipe handling assembly configured to use fluid pressure to provide torque forces to set or release slips from a pipe. Set down force or other frictional measures on a pipe collar are not required. A method to create reactive torque force comprising a series of gears interconnected with each other through a clutch that can be engaged and disengaged. A link may be provided to a top drive rail via a gripperbox which provides reactive force to stop rotation of a power screw female (threaded nut) to facilitate threading action to set or release slips on pipe. Reactive force may be created using a plurality of axial pistons attached to a moveable half of a hirth coupling. Other friction-creating members (such as, for example, a brake pad material or similar material) may be used to create frictional forcesbetween two surfaces.