The present invention relates to a system for facilitating the transmission of rotational torque through the tool when in tension but allowing free rotation without torque transmission when the tool is in compression and stroked partially or fully closed.

A vibration mitigation tool may include a mandrel portion, a sleeve portion arranged about the mandrel portion and configured to move longitudinally and rotationally relative to the mandrel portion. The tool may also include a spring stack configured to control compression on the vibration mitigation tool through compression of the spring stack and to control tension on the vibration mitigation tool through compression of the spring stack. A helical engagement between the mandrel portion and the sleeve portion may also be provided.

This disclosure includes various connection devices and assemblies, such as telescoping riser joints, that include at least one of the present connection devices. Some of the present connection devices, for example, include a housing having a bore therethrough; a locking ring rotatably movable relative to the housing between a first position and a second position; and an engagement member laterally moveable relative to the bore of the housing between a retracted position and an extended position. In some such connection devices, the locking ring is configured such that movement from the first position to the second position causes the engagement member to move from the retracted position to the extended position.

A high frequency torsional oscillation mitigation tool for use in a downhole drilling assembly. The tool has a first end, a second end, and a one-way coupling therebetween. The one-way coupling has a first part connected to rotate with the first end and a second part connected to rotate with the second end. The one-way coupling has an engaged condition in which the first part and the second part can rotate together in a first rotational direction whereby drill string rotation can be communicated to the drill bit. The one-way coupling has a disengaged condition in which the first part can rotate relative to the second part in a second rotational direction. The one-way coupling can have multiple sets of driving elements along its longitudinal axis. The tool can include a locking mechanism to override the one-way coupling for recovering a stuck downhole assembly.

A system for drilling a borehole into the earth's subsurface includes a drill bit configured to rotate and penetrate through the earth's subsurface, and a vibration isolation device configured to isolate vibration that is caused at the drill bit, the vibration having an amplitude. The amplitude of the vibration downhole of the vibration isolation device is at least 20% higher than the amplitude of the vibration uphole of the vibration isolation device.

In accordance with presently disclosed embodiments, a system and method for rotationally orienting two wellbore tool components on a tool string relative to each other is provided. The system may include an alignment sub that is simple to operate and allows for quick adjustments to the relative orientations of downhole tool components. The disclosed alignment sub may include a first tubular component on one side and a second tubular component on the other side, and these tubular components are coupled together. The disclosed alignment sub utilizes an axially deformable and variable length sleeve attached to the first tubular component and adjacent to a tip of the second tubular component. The sleeve may provide an appropriate standoff distance between the opposing tubular components while enabling the components to be rotated relative to each other up to at least one full rotation about an axis of the alignment sub.

An embodiment of a coupling device is configured to be disposed in a borehole string in a borehole in a subterranean region. The coupling device includes a coupler body having a longitudinal axis, the coupler body including an elongated shaft extending along the longitudinal axis and configured to carry loads through the coupling device, a stiffness control device connected to the elongated shaft, the stiffness control device configured to adjust a bending stiffness of the coupler body, and an actuator configured to cause the stiffness control device to adjust the bending stiffness of the coupler body.

An offshore method includes providing an elongate support string for extending between a mobile offshore drilling unit and a seabed location. The string has an upper portion and a lower portion, and an articulated joint is provided between the upper portion and the lower portion. The provision of the articulated joint maintains the lower portion of the elongate support string in a substantially vertical orientation and increases the safe operating radius of the mobile offshore drilling unit or increases the speed at which the unit may transit through the sea with objects suspended via the elongate support string.

A downhole shock absorbing sub which includes a tubular main stem extending through a sub housing and a lateral shock absorbing assembly positioned within the sub housing. The lateral shock absorbing assembly includes an activator ring positioned around the main stem, the activator ring including a plurality of wedge inserts positioned around a perimeter of the activator ring. A reaction collar is positioned on each side of the activator ring with the reaction collars including ramp surfaces engaged by the wedge inserts. A spring system is positioned to resist movement of the reaction collars away from the activator ring, whereby lateral movement of the main stem causes the wedge inserts to move the reaction collars against the spring system.

A system for damping vibration in a drill string can include a magnetorheological fluid valve assembly having a supply of a magnetorheological fluid. A remanent magnetic field is induced in the valve during operation that can be used to provide the magnetic field for operating the valve so as to eliminate the need to energize the coils except temporarily when changing the amount of damping required. The current to be supplied to the coil for inducing a desired magnetic field in the valve is determined based on the limiting hysteresis curve of the valve and the history of the magnetization of the value using a binary search methodology. The history of the magnetization of the valve is expressed as a series of sets of current and it resulting magnetization at which the current experienced a reversal compared to prior values of the current.