A coupler includes a main body that has an inner bore. The inner bore has a non-circular profile and a longitudinal axis. The coupler includes a cross aperture disposed in the main body. The cross aperture has an axis that is nonintersecting with the longitudinal axis of the main body.

A cellar around a wellbore is formed or deepened with an excavating system that is capable of being assembled around an existing wellbore. The system includes an excavating unit having an annular body with a cutting surface that excavates cuttings from ground around the wellbore. The cuttings are directed up through a slot in the body, and are collected inside a receptacle set in a recess of the body. An opening is formed in a side of the receptacle when in the body, and through which the cuttings pass from the slot into the receptacle. The receptacle is removable from within the recess and cuttings collected within are emptied. When the receptacle is removed from the recess, the opening is automatically covered to retain the cuttings inside the receptacle. Another cellar around a different wellbore is formed by disassembling the excavating system and relocating it to the different wellbore.

Embodiments of a downhole drilling assembly generally include rotatable upper and lower drilling assemblies, and a drill bit, wherein an upper drilling assembly contains a mud motor adapted for clockwise stator rotation and counter-clockwise rotor rotation, whereby a lower drilling assembly is rotatable in the opposite direction of the upper drilling assembly or maintainable in a non-rotating state. The apparatus further includes sensors for continuously transmitting information relating thereto to the surface. Embodiments of a downhole clutch joint generally include a box end sub, a pin end sub, and a ratchet sleeve system containing a clutch joint mechanism, wherein the downhole clutch joint prevents rotation of a downhole drilling assembly in an undesired direction. Method embodiments generally include continuously measuring physical properties and/or drilling parameters, continuously transmitting information relating thereto, and controlling lower drilling assembly rotation in a non-rotating state or in the opposite direction of an upper drilling assembly.

An example method for control of a drilling assembly includes receiving measurement data from at least one sensor coupled to an element of the drilling assembly positioned in a formation. An operating constraint for at least a portion of the drilling assembly may be determined based, at least in part, on a model of the formation and a set of offset data. A control signal may be generated to alter one or more drilling parameters of the drilling assembly based, at least in part, on the measurement data and the operating constraint. The control signal may be transmitted to a controllable element of the drilling assembly.

A coupler includes a main body that has an inner bore. The inner bore has a non-circular profile and a longitudinal axis. The coupler includes a cross aperture disposed in the main body. The cross aperture has an axis that is nonintersecting with the longitudinal axis of the main body. The coupler also includes a sleeve that is positioned around an exterior surface of the main body. The sleeve has at least one drilling fluid flow passage.

A mining system with an inertial guidance system configured to enable precise excavation of geological material without a need to advance a survey line over a long distance and/or nonlinear excavation path, thereby maximizing productivity of the mind by minimizing a width of un-mined material necessary for support between adjacent excavation paths and minimizing equipment downtime.

A mining system with an inertial guidance system configured to enable precise excavation of geological material without a need to advance a survey line over a long distance and/or nonlinear excavation path, thereby maximizing productivity of the mind by minimizing a width of un-mined material necessary for support between adjacent excavation paths and minimizing equipment downtime.

A coupler includes a main body that has an inner bore. The inner bore has a non-circular profile and a longitudinal axis. The coupler includes a cross aperture disposed in the main body. The cross aperture has an axis that is nonintersecting with the longitudinal axis of the main body.

A system and method for stall recovery of mud motors may be implemented in a steering control system. The stall recovery system and method may involve automatic detection of a stall of a mud motor during drilling controlled by the steering control system, and may respond to the stall in a rapid and controlled manner to avoid or minimize damage to the mud motor, such as by immediately reducing mud pressure and stopping rotary drilling, if used, faster than a typical human operator could perform. The stall recovery system and method may farther take actions to automatically restart drilling.

A drilling assembly and method of drilling a wellbore is disclosed. The drilling assembly includes a steering device having a tilt device and an actuation device. A first section and a second section of the drilling assembly are coupled through the tilt device, wherein the first section is attached to a drill bit. The actuation device includes an electromechanical actuator and causes a tilt of the tilt device to cause the first section attached to the drill bit and the drill bit to tilt relative to the second section. The wellbore is drilled using the drill bit. The electromechanical actuator is actuated to tilt the tilt device to cause the first section attached to the drill bit and the drill bit to tilt relative to the second section and to maintain the tilt geostationary while the drilling assembly is rotating to form a deviated section of the wellbore.