A technique facilitates controlled creation of pressure waves in a downhole environment. The technique enables creation of, for example, dynamic underbalance (DUB) pressure waves or dynamic overbalance (DOB) pressure waves which can be used to perform desired activities downhole. According to an embodiment, a pump is coupled with a pressure chamber and conveyed downhole into a borehole to a desired location. The pump may be operated downhole to change a pressure level in the pressure chamber until a sufficient pressure differential exists between an interior and an exterior of the pressure chamber. A release mechanism in communication with the pressure chamber is then rapidly opened to establish the desired pressure wave as the differing pressures equalize.

A system and method set a liner hanger in a borehole by actuating a hydraulic setting mechanism on the hanger to engage slips in the borehole. A setting tool runs the hanger into position. A reserve volume of the tool holds a clean fluid separate from the borehole. A piston of the tool has a tool volume for the fluid. During run in, pressure in the tool volume is balanced to hydrostatic pressure by drawing actuation fluid from the reserve volume to the tool volume through a check valve. To set the hanger, a plug is engaged on a seat in the tool, tubing pressure is applied behind the engaged plug, and the seat is unlocked. With more applied pressure, the piston moves, reduces the tool volume, and intensifies pressure of the clean fluid communicated to the hanger's setting mechanism. Over-pressure can be handled by a venting valve.

A thru-tubing recover string (10) and method of moving a stuck object (14) in tubing in a well (16). A bottom hole assembly (22) is connected to a work string and includes a first (32) and a second tool (34), each tool configured to apply a force to the object in order to move the object (14), the first force being an impulse force, the second force being a static force, and the tools being operable independently so that an operator can apply either force in the event that application of one type of force on the object fails to move the object. Embodiments are described for the first tool (32) being a hammer tool or a jar and the second tool being a pulling tool such as a jack. The invention finds application in removing stuck objects such as plugs or actuating elements on tools such as sliding sleeves in production tubing.

A pressure intensifier for morphing tubulars downhole. An elongate mandrel defines an inner bore, being co-axially located within an elongate hollow outer cylindrical body to form a co-axial annular bore therebetween. Pistons are mounted upon the mandrel with each piston having an annular fluid facing face extending across the annular bore, with fluid communication between the inner bore and the annular bore to act upon each face. Stops are located on an inner surface of the outer cylindrical body to limit travel of each piston. A morph fluid is located in the annular bore between an opposing face of a first piston and a first stop, with the first stop having delivery ports to deliver the morph fluid at a greater pressure than the pressure of fluid delivered through the inner bore.

A control unit includes a rotatable tubular body that rotates around a spindle. A torque transfer unit may be attached to the tubular body and the spindle. A force applied to the torque transfer unit by a biasing element may control a first torque applied by the tubular body to the spindle. The first torque is independent of a rotational velocity of the tubular body. A second torque is applied to the spindle with a torque generator, the second torque controlling the net torque. Controlling the net torque allows the absolute orientation of the control unit to be controlled.

A thru-tubing recover string (10) and method of moving a stuck object (14) in tubing in a well (16). A bottom hole assembly (22) is connected to a work string and includes a first (32) and a second tool (34), each tool configured to apply a force to the object in order to move the object (14), the first force being an impulse force, the second force being a static force, and the tools being operable independently so that an operator can apply either force in the event that application of one type of force on the object fails to move the object. Embodiments are described for the first tool (32) being a hammer tool or a jar and the second tool being a pulling tool such as a jack. The invention finds application in removing stuck objects such as plugs or actuating elements on tools such as sliding sleeves in production tubing.

A system and method set a liner hanger in a borehole by actuating a hydraulic setting mechanism on the hanger to engage slips in the borehole. A setting tool runs the hanger into position. A reserve volume of the tool holds a clean fluid separate from the borehole. A piston of the tool has a tool volume for the fluid. During run in, pressure in the tool volume is balanced to hydrostatic pressure by drawing actuation fluid from the reserve volume to the tool volume through a check valve. To set the hanger, a plug is engaged on a seat in the tool, tubing pressure is applied behind the engaged plug, and the seat is unlocked. With more applied pressure, the piston moves, reduces the tool volume, and intensifies pressure of the clean fluid communicated to the hanger's setting mechanism. Over-pressure can be handled by a venting valve.

A control unit includes a rotatable tubular body that rotates around a spindle. A torque transfer unit may be attached to the tubular body and the spindle. A force applied to the torque transfer unit by a biasing element may control a first torque applied by the tubular body to the spindle. The first torque is independent of a rotational velocity of the tubular body. A second torque is applied to the spindle with a torque generator, the second torque controlling the net torque. Controlling the net torque allows the absolute orientation of the control unit to be controlled.

A system and method set a liner hanger in a borehole by actuating a hydraulic setting mechanism on the hanger to engage slips in the borehole. A setting tool runs the hanger into position. A reserve volume of the tool holds a clean fluid separate from the borehole. A piston of the tool has a tool volume for the fluid. During run in, pressure in the tool volume is balanced to hydrostatic pressure by drawing actuation fluid from the reserve volume to the tool volume through a check valve. To set the hanger, a plug is engaged on a seat in the tool, tubing pressure is applied behind the engaged plug, and the seat is unlocked. With more applied pressure, the piston moves, reduces the tool volume, and intensifies pressure of the clean fluid communicated to the hanger's setting mechanism. Over-pressure can be handled by a venting valve.

A hydraulic pressure converter with a force multiplier converts fluid pressure pumped down a work string from the surface into a multiplied linear force. The multiplied linear force can be used to operate downhole tools to perform tasks requiring the application of linear force.