A drilling system configured to reduce friction during slide drilling. The drilling system has a drill string comprising a fluid-driven drill stage such as a mud motor; a variable frequency drive configured to oscillate the drill string via a quill and a sensor array. The sensor array measures the torque applied to the quill and the angular position of the quill. A controller is used to control the variable frequency drive based on the determined applied torque and quill angular position to meet predetermined oscillation turn-around criteria and to reduce the time to reduce the angular velocity of the quill from a maximum rotational speed to zero in an oscillation cycle.

A downhole drilling apparatus may comprise a rotatable body with fixed cutting elements protruding from an exterior thereof. To form a subterranean borehole, the fixed cutting elements, spaced at a constant radius from a rotational axis of the body, may degrade an earthen formation as the body rotates. The body may also have a rotatable cutting element protruding from its exterior. To remove material from an interior wall of the borehole, the rotatable cutting element may be positioned in a first rotational orientation wherein it extends radially beyond the constant radius of the fixed cutting elements. An amount of material being removed may be altered by rotating the rotatable cutting element into a second rotational orientation wherein it remains radially within the constant radius.

A downhole drilling apparatus may comprise a rotatable body with fixed cutting elements protruding from an exterior thereof. To form a subterranean borehole, the fixed cutting elements, spaced at a constant radius from a rotational axis of the body, may degrade an earthen formation as the body rotates. The body may also have a rotatable cutting element protruding from its exterior. To remove material from an interior wall of the borehole, the rotatable cutting element may be positioned in a first rotational orientation wherein it extends radially beyond the constant radius of the fixed cutting elements. An amount of material being removed may be altered by rotating the rotatable cutting element into a second rotational orientation wherein it remains radially within the constant radius.

Apparatus and operational methods thereof, including a top drive, a rotation sensor, and a processing device. The top drive connects with an upper end of a drill string. The rotation sensor facilitates rotational distance measurements indicative of rotational distance achieved by the top drive. The processing device causes the top drive to impart rotational oscillations alternatingly in opposing directions to the upper end of the drill string while maintaining a downhole toolface orientation during a slide drilling operation, such that each rotational oscillation rotates the upper end of the drill string through a base rotational distance. The processing device also causes the top drive to change the downhole toolface orientation by an offset rotational distance by adding the offset rotational distance and an overshoot rotational distance to the base rotational distance of an instance of the rotational oscillations.

Apparatus and operational methods thereof, including a top drive, a rotation sensor, and a processing device. The top drive connects with an upper end of a drill string. The rotation sensor facilitates rotational distance measurements indicative of rotational distance achieved by the top drive. The processing device causes the top drive to impart rotational oscillations alternatingly in opposing directions to the upper end of the drill string while maintaining a downhole toolface orientation during a slide drilling operation, such that each rotational oscillation rotates the upper end of the drill string through a base rotational distance. The processing device also causes the top drive to change the downhole toolface orientation by an offset rotational distance by adding the offset rotational distance and an overshoot rotational distance to the base rotational distance of an instance of the rotational oscillations.

Systems and methods determine friction in a borehole during drilling operations. A drilling system applies oscillatory angular movement at the top of a drill string in a wellbore during drilling by the drilling system, and measures a torque applied to the drill string and an angular position of the drill string. Based on the measured torque and the measured angular position, the drilling system computes a friction between the borehole and the drill string. This can be repeated during drilling of the wellbore to determine multiple friction values, corresponding to various depths of the borehole. Based on the computed friction, the drilling system can perform one or more actions resulting in modified drilling operation. The systems and methods also include oscillating a casing in the borehole, measuring the torque and angular position of the casing, and determining a friction value, which can be repeated to develop a wellbore friction profile.

An axial linkage acting between the main body and the gripping assembly of a tool for gripping tubular workpieces includes a drive cam body that coaxially engages an intermediate cam body via a drive thread, with the intermediate cam body coaxially engaging a driven cam body via a driven thread, and with the drive thread and the driven thread having opposite orientations. The linkage includes a latch mechanism for preventing relative axial displacement of the drive cam body and the driven cam body. In operation while unlatched, the linkage converts bi-directional relative rotation into relative axial movement of the drive cam body and the driven cam body, thus increasing or decreasing the overall length of the linkage according to the rotational direction. The linkage can be re-latched using any of multiple operational sequences.

Arrangement of a ground drilling device for the pushing or pulling introduction of a drill string into the ground, wherein the arrangement has a frame and a carriage which can be moved back and forth relative to the frame with a translatory movement, wherein at least one rolling element is provided, which is configured to roll during the translatory movement of the carriage, and a conversion device is provided, which is connected to the rolling element and is configured to convert the rotary movement of the rolling element into a rotary movement of the drill string.

Arrangement of a ground drilling device for the pushing or pulling introduction of a drill string into the ground, wherein the arrangement has a frame and a carriage which can be moved back and forth relative to the frame with a translatory movement, wherein at least one rolling element is provided, which is configured to roll during the translatory movement of the carriage, and a conversion device is provided, which is connected to the rolling element and is configured to convert the rotary movement of the rolling element into a rotary movement of the drill string.

An axial linkage acting between the main body and the gripping assembly of a tool for gripping tubular workpieces includes a drive cam body that coaxially engages an intermediate cam body via a drive thread, with the intermediate cam body coaxially engaging a driven cam body via a driven thread, and with the drive thread and the driven thread having opposite orientations. The linkage includes a latch mechanism for preventing relative axial displacement of the drive cam body and the driven cam body. In operation while unlatched, the linkage converts bi-directional relative rotation into relative axial movement of the drive cam body and the driven cam body, thus increasing or decreasing the overall length of the linkage according to the rotational direction. The linkage can be re-latched using any of multiple operational sequences.