A tool is incorporated into a tubing string and is run into a wellbore until an agitator at a bottom of the tool engages an obstruction in the wellbore. A helical drive arrangement between a mandrel and a sleeve causes the sleeve on the outside of the tool, to which the agitator is attached, to rotate as the mandrel is reciprocated between a downstroke and an upstroke. Rotation of the agitator disrupts the obstruction forming debris therefrom and a slurry of the debris in wellbore fluid. At the same time, reciprocation of the mandrel causes a standing valve and a travelling valve in the tool to be alternately opened and closed for pumping the slurry into the tool and from the tool into the tubing string for storage therein. Periodically the tool is tripped to surface and the stored debris is removed from the tubing string.

A drill string circulation apparatus has a sleeve member with an elongated tubular body and a longitudinal bore, with an outer diameter suitable for being sealingly gripped by a blowout preventer. A drill string has an outer diameter sized to fit within the sleeve member bore, and has one or more seals disposed on an exterior surface. The seals are sized to create a seal between said sleeve member and the drill string, when the drill string and seals are positioned within the sleeve member bore, while said drill string is still capable of reciprocation and/or rotation within the sleeve member when the seals are within the sleeve member bore.

An oscillation reduction tool configured to prevent or reduce high frequency torsional oscillation by torsionally decoupling a rotary steerable system from a bottom hole assembly, which includes a drilling motor. The tool may convert high frequency torsional oscillation into an internal axial movement without axial displacement of the tool's outer housing. The oscillation reduction tool may flatten an amplitude of high frequency torsional oscillation spikes throughout a spring arrangement. The mechanical energy associated with the internal axial movement is reduced through an internal shock absorbing mechanism, such as fluid movement through a nozzle or annular space. The oscillation reduction tool functions to reduce high frequency torsional oscillation independent of the weight on the bit of the drill string.

An internal peeping detection-while-drilling system includes an intelligent probing rod, cable drill pipes, a signal relay sub, a ground control terminal, a data interpretation and goaf reconstruction imaging software system, and a remote data transmission system, where the intelligent probing rod includes an up-down separated protective transmission mechanism and an instrument cabin; the intelligent probing rod includes a lower end connected to a drilling bit, and an upper end connected to each of the cable drill pipes; the instrument cabin is provided in the up-down separated protective transmission mechanism, and provided with a sonar-lidar-audio/video sensor assembly; the cable drill pipes are connected to each other to form a cable and data transmission channel; the signal relay sub is provided between the cable drill pipes at intervals; and an uppermost end of the cable drill pipe is connected to the ground control terminal.

An apparatus may include a connector sub rigidly securable to a conveyance for running the connector sub along a wellbore and a spool mandrel coupled to a downhole end of the connector sub. The spool mandrel is rotatable with respect to the connector sub. Further, the apparatus may include a control line extending between the connector sub and the spool mandrel. The control line is displaceable to permit rotation of the spool mandrel with respect to the connector sub. Additionally, the apparatus may include at least one biasing member for biasing the spool mandrel to a neutral position with respect to the connector sub.

A sub-assembly, rock drilling rig and method of absorbing vibrations in rotary and DTH drilling. The sub-assembly is for transmitting torque and axial forces between a rotating head and a drilling tool. There is an axial floating arrangement for providing an allowed limited axial relative movement between coupling elements of the sub-assembly. The arrangement comprises several axial drive pins for transmitting the torque. First ends of the drive pins are mounted immovably and second ends are mounted with clearances, whereby the drive pins can bend under torsional shocks. Thus, the drive pins serve as torsional dampening elements.

A device for damping vibrations of a rotary drill string in motion in a wellbore, a related method, drill string and drill string sub or section, where at least one component of motion of the drill string is communicated to the device, and brake means counter the vibrations, resisting the motion in dependence upon the speed of motion. The device may have an outer sleeve arranged on an inner, tubular body which is rotatably arranged within the outer sleeve. Roller wheels support the sleeve on the wellbore wall and facilitate longitudinal movement of the device and prevent rotational slipping of the outer sleeve relative to the wall upon rotating the tubular body and drill string. One brake part of the brake means on the outer sleeve and another on the tubular body operate to resist rotational vibration components.

A downhole tool (30) particularly for controlling torque and torsion and also for absorbing/dampening vibration in a downhole string is provided and comprises an inner mandrel (1, 7, 11, 15) and an outer mandrel (14, 13, 12, 19) and a coupling mechanism (8) to couple the inner and the outer mandrel, the coupling mechanism comprising one or more longitudinally elongate members (8) acting between the inner and outer mandrel, wherein the one or more longitudinally elongate members are substantially fixed in their longitudinal length but substantially do not resist relative compressive longitudinal movement occurring between the inner and outer mandrels. The coupling mechanism is arranged such that compression of the inner and outer mandrels results in compression of the one or more longitudinally elongate members without necessarily resulting in relative rotation of the inner and outer mandrels.

The drill string axial vibration attenuator (10) is installed in the bottom hole assembly (BHA) of a drill string to attenuate axial and torsional vibrations of the drill string. The vibration attenuator (10) includes a massive elongate stabilizer (14) installed in a sealed chamber (12) that is, in turn, rigidly installed within the BHA of the drill string. Clearance between the inner wall of the chamber (12) and the stabilizer (14) is provided to preclude frictional interference therebetween. The stabilizer mass (14) is supported from below by a compression spring (18) and a shock absorber or damper (24) at the top to allow movement of the mass (14). The stabilizer (14) substantially reduces or eliminates axial and coupled torsional vibration of the drill string when the mass of the stabilizer (14), the rate of the spring, and the damper stiffness are properly configured.

Systems and methods are disclosed herein that include providing an active torsion damper control system that includes a rotatable component (206) and a rotatable measurement interface (302) disposed on the rotatable component, the rotatable measurement interface having at least one torsional strain gauge configured to measure a strain of the rotatable component, a torque management (306) computer configured to determine a resonant frequency of the rotatable component and a corrective torque needed to be applied to the rotatable component to excite the resonant frequency as a function of the measured strain, and a correction motor (308) configured to impart the corrective torque on the rotatable component.