A downhole oscillation tool and method for axially vibrating a drill bit. In some embodiments, modular actuation assemblies may be provided, which may be readily interchanged between a housing and a shaft to axially vibrate the shaft with respect to the housing. Modular actuation assemblies may be mechanical, hydraulic, electric, or piezoelectric, for example, and may be characterized by differing oscillation frequencies. In some embodiments, a piezo element may be provided between the housing and the shaft.

An electromagnetic jarring tool and related systems and methods provide for the use of an electromagnetic system to generate jarring forces within a wellbore. The electromagnetic jarring tool includes a chamber having a first end and a second end, a magnetic hammer disposed within the chamber, and an electromagnet operable to generate an electromagnetic field across at least a portion of the chamber. The magnetic hammer is operable to move toward the second end of the chamber in response to the electromagnetic field to deliver an impact. One or more electromagnets may be included to enhance operation of the tool, and the tool may be actuated by a surface controller that selectively delivers electrical power or a control signal to the tool to specify a mode of operation of the electromagnetic jarring tool.

A method for signal communication between a well drilling instrument and the Earths surface includes generating an electromagnetic field in an instrument disposed in drill string used to drill a wellbore. The electromagnetic field includes encoded measurements from at least one sensor associated with the instrument. A signal corresponding to an amplitude and/or phase of the electromagnetic field is measured between the drill string and a surface electrode when the drill string is substantially electrically isolated from a well casing. A signal corresponding to the amplitude and/or phase is measured between the casing and a surface electrode when the casing and the drill string are in electrical contact with each other.

An apparatus for applying a magnetic pressure to a work piece includes an inductor configured to be disposed in proximity to the work piece and a controller electrically connected to the inductor and configured to control a supply of electrical power in order to output a first voltage over a selected frequency range to determine a frequency that provides a maximum current or a frequency that provides a current within a selected range of the maximum current to the inductor.

A method for installing a tool in a downhole system including running the tool to a target location within a tubular structure, creating a magnetic pulse, and urging the tool toward the tubular structure at a minimum velocity of 200 meters per second with the magnetic pulse. A method for actuating a downhole tool including creating a magnetic pulse, coupling the magnetic pulse to a workpiece and moving the workpiece with the pulse, the workpiece achieving a minimum velocity of 200 meters per second.

A downhole stroking tool (1) comprising a housing (2), a first chamber (3), a first tool part (4) comprising a pump unit (5) providing pressurised fluid to the chamber, a shaft (6) penetrating the chamber, and a first piston (7) dividing the first chamber into a first chamber section (8, 8a) and a second chamber section (9, 9b). The piston is connected to or forms part of the housing which forms part of a second tool part (10) and is slidable in relation to the shaft so that the housing moves in relation to the shaft, the shaft being stationary in relation to the pump unit during pressurisation of the first or the second chamber section, thereby generating a pressure on the piston, wherein the shaft is fixedly connected with the first tool part, and wherein the housing is slidable in relation to the first tool part and overlaps the first tool part.

A force stacking assembly for use with an earth boring system that includes a series of actuators that each generate a force, and that are arranged to create a combined force that is cumulative of all of the actuators. The actuators include members that react in response to an applied stimulus, such as from an electrical current or magnetic field. The members are arranged in series in a hollow housing, planar bulkheads are transversely mounted in the housing. Each of the members have an end axially abutting a corresponding bulkhead. Ends of each member distal from it corresponding bulkhead couple to a ram member, that in turn couples to a drill bit. Energizing the members causes each to exert a force against the ram member, which is transferred to the bit.

A force stacking assembly for use with an earth boring system that includes a series of actuators that each generate a force, and that are arranged to create a combined force that is cumulative of all of the actuators. The actuators include members that react in response to an applied stimulus, such as from an electrical current or magnetic field. The members are arranged in series in a hollow housing, planar bulkheads are transversely mounted in the housing. Each of the members have an end axially abutting a corresponding bulkhead. Ends of each member distal from it corresponding bulkhead couple to a ram member, that in turn couples to a drill bit. Energizing the members causes each to exert a force against the ram member, which is transferred to the bit.

The invention relates to a Drilling robot for drilling a borehole. The drilling robot (2) is purely electrically driven and comprises a movement unit for moving the drilling robot through the borehole, a rotary hammer unit with a drill head (21), a rotating system (22) and a hammering system (23). The rotating system (22) is adapted to rotate the drill head (21) and the hammering system (23) is adapted to hammer with the drill head (21). The hammering system (23) is adapted to operate according to an electro-pneumatic principle in order to generate an electro-pneumatic stroke.

The invention relates to a Drilling robot for drilling a borehole. The drilling robot (2) is purely electrically driven and comprises a movement unit for moving the drilling robot through the borehole, a rotary hammer unit with a drill head (21), a rotating system (22) and a hammering system (23). The rotating system (22) is adapted to rotate the drill head (21) and the hammering system (23) is adapted to hammer with the drill head (21). The hammering system (23) is adapted to operate according to an electro-pneumatic principle in order to generate an electro-pneumatic stroke.