An example downhole motor may include a first housing and a second housing with first and second portions characterized by non-parallel longitudinal axes. The second housing may be rotatably coupled to the first housing, and the first portion of the second housing may be arranged in a fixed, non-parallel longitudinal orientation with the first housing. A drive shaft may be at least partially within the first housing, and the motor may further comprise a selectively engageable torque coupling between the drive shaft and the second housing, positioned within the first housing.

A drilling machine for a wellbore is provided. The drilling machine may include a dynamic lateral pad that is movable between an extended and retracted position. In the extended position, the pad moves the drill bit in a direction for drilling. The drilling machine may include a dynamic lateral cutter that is movable between an extended and retracted position. In at least the extended position, the cutter engages the wellbore and removes formation. The drilling machine may include a monolithic or integral drill bit/drive shaft to reduce the distance between a positive displacement motor and a distal end of the monolithic or integral drill bit/drive shaft. The drilling machine may include separate cutting structures that have different rotational speeds and can further utilize the integral drill bit/drift shaft and/or a bent housing that generates an off-axis rotation which helps optimize the formation removal in the center area of the wellbore.

The method of maintaining drill bit advancement in an underground formation that contains shale, including providing an electrical signal from an insulated gap location in a drill string substantially directly behind the bit in the formation, detecting substantial change in a signal as the bit advances, and changing the direction of drilling of the bit as a function of a signal change, to thereby maintain the direction of bit advancement in the formation. A method is disclosed for detecting the existence and direction of adjacent bed boundaries. A short hop transmitter assembly generates a signal that is detected by an associated receiver assembly. The received signal(s) are tied to the azimuthal orientation of the transmitter or receiver and processed to yield the direction and/or the distance of the bed boundary. This information is transmitted to the surface via surface telemetry for real-time control of the drilling assembly to stay within, or to enter, a pay zone.

A drill string steering system includes a motor and a rotary valve body disposed in a tool body. The motor includes a motor shaft coupled to the motor and extending within a central bore of the tool body. The motor shaft has a downhole engagement portion that includes a first splined surface. The rotary valve body includes a disk-shaped component and a valve shaft coupled to the disk-shaped component and extending uphole of the disk-shaped component. The valve shaft includes a second splined surface engageable with the first splined surface for rotation of the motor shaft to be imparted to the rotary valve body.

The present disclosure describes various embodiments, as well as features and aspects thereof, of an improved drill bit assembly for a percussion boring system. More specifically, one non-limiting embodiment of an improved drill bit assembly for a percussion boring system comprises a bit and a product engagement member. The bit comprises a slant faced head and at least one exhaust port. The product engagement member comprises a product coupling portion and at least one fluid restriction portion. This improved drill bit assembly is such that, when the product engagement member is detachably engaged with the slant faced head of the bit, a first portion of the fluid stream expelled from the bit is directed substantially forward of the slant faced head and a second portion of the fluid stream is directed substantially rearward from the slant faced head.

A wellbore assembly is provided that can include a first motor housing assembly member and a second motor housing assembly member that can bend relative to the first motor housing assembly at a bend location. The assembly can also include a strain gauge positioned on a first side of the bend location to determine an amount of bend of the second motor housing assembly member relative to the first motor housing assembly member by determining a strain. Based on the strain, the amount of bend or bend direction of the second motor housing assembly member relative to the first motor housing assembly member can be determined.

A drilling system performs underground boring using a drill rig and a boring tool which is configured for moving through the ground under control of the drill rig to form an underground bore. A monitoring arrangement, forming part of the system, includes a detection arrangement at the drill rig for monitoring at least one operational parameter to produce a data signal relating to at least one of a utility to be installed in the underground bore, the drill rig and the boring tool. A portable device forms another part of the system for receiving the data signal relating to the operational parameter for use by the portable device. A communication arrangement, for example using telemetry, transfers the data signal from the drill rig to the portable device. The operational parameter may be monitored for the purpose of preventing equipment failure.

A method for wellbore directional drilling includes selecting a starting and stopping spatial position of at least one portion of the wellbore. A sequence of sliding and rotary drilling operations within the portion is determined to calculate a wellbore trajectory. The sequence has at least one drilling operating parameter. The operations include a constraint on the drilling operating parameter or the calculated trajectory. The calculated trajectory includes a projected steering response of a steerable motor in response to the at least one drilling operating parameter. Drilling the portion of the wellbore is started. A spatial position of the wellbore during drilling is determined at at least one point intermediate the starting and stopping positions. Using a relationship between the projected steering response and the drilling operating parameter, the drilling parameter and/or the constraint are adjusted based on the measured spatial position and the stopping spatial position.

A drilling machine for a wellbore is provided. The drilling machine may include a dynamic lateral pad that is movable between an extended and retracted position. In the extended position, the pad moves the drill bit in a direction for drilling. The drilling machine may include a dynamic lateral cutter that is movable between an extended and retracted position. In at least the extended position, the cutter engages the wellbore and removes formation. The drilling machine may include a monolithic or integral drill bit/drive shaft to reduce the distance between a positive displacement motor and a distal end of the monolithic or integral drill bit/drive shaft. The drilling machine may include separate cutting structures that have different rotational speeds and can further utilize the integral drill bit/drift shaft and/or a bent housing that generates an off-axis rotation which helps optimize the formation removal in the center area of the wellbore.

Systems and methods presented herein include a drilling system that includes a deflecting device having an internal passage extending therethrough, and a flexible drilling assembly configured to extend through the internal passage of the deflecting device, and to create a perforation lateral tunnel in a wellbore. The flexible drilling assembly includes a flexible drive shaft configured to rotate relative to the internal passage of the deflecting device. The flexible drilling assembly also includes a cutting bit disposed at a first axial end of the flexible drilling assembly. The flexible drilling assembly further includes a slider tube disposed at a second axial end of the flexible drilling assembly. In addition, the flexible drilling assembly includes a slider radially disposed within the slider tube. The slider is hydraulically configured to compensate for expansion and compression of the flexible drive shaft while the perforation lateral tunnel is being created in the wellbore by the flexible drilling assembly.