A mechanically locking hydraulic jar device includes an outer sleeve, an inner sleeve partially disposed in an inner bore of the outer sleeve, and a mechanical lock engaging the outer sleeve and the inner sleeve in a default position to axially secure the inner sleeve to the outer sleeve. Activation of the hydraulic jar disables the mechanical lock to allow axial movement of the inner sleeve relative to the outer sleeve, which generates an impact force when the inner sleeve reaches an activated position. The hydraulic jar device also includes an upward block and a downward block configured to limit the upward and downward axial movement, respectively, of the inner sleeve relative to the outer sleeve when the mechanical lock is disabled.

A downhole impact apparatus operable to impart an impact to an object within a wellbore. The impact apparatus may include a housing, a first chamber within the housing, a second chamber within the housing, and a piston assembly slidably disposed within the housing. The piston assembly may include a first piston slidably disposed within the first chamber and dividing the first chamber into a first volume and a second volume, a second piston slidably disposed within the second chamber, and a shaft connecting the first and second pistons. The first volume may be open to a space external to the housing and the second volume may be fluidly isolated from the space external to the housing. Relative movement between the piston assembly and the housing ends with the impact. The second chamber may be configured to contain a fluid to prevent relative movement between the piston assembly and the housing.

A jarring apparatus includes first and second jarring assemblies rotatable relative to each other. A first impact surface is provided on the first jarring assembly and a second impact surface is provided on the second jarring assembly, wherein, in use, the first and second impact surfaces are biased together. A first lifting structure is rotatably fixed relative to the first jarring assembly and a second lifting structure is rotatably fixed relative to the second jarring assembly, the first and second lifting structures being configured to cooperate during relative rotation therebetween to cause cyclical relative displacement in one axial direction to define a lifting phase and relative displacement in a reverse axial direction to define a dropping phase. The first and second lifting structures are axially fixed relative to their associated jarring assembly during the lifting phase to provide axial separation between the first and second impact surfaces, and the second lifting structure is axially released relative to the second jarring assembly prior to initiation of the dropping phase to permit the first and second impact surfaces to be axially impacted together.

A method of dislodging a tubular string or well equipment connected to the tubular string can include connecting a dislodging tool in the tubular string, so that a flow passage of the dislodging tool extends through the tubular string, deploying a plug into the dislodging tool, applying a pressure differential across the plug, thereby displacing the plug through a seat of the dislodging tool, and dislodging the tubular string or the component in response to the displacing. A dislodging system can include a dislodging tool connected as part of a tubular string, the dislodging tool including a flow passage and a seat configured to sealingly engage a plug deployed into the tubular string, and at least one of a jarring force, load, impact, shock wave, elastic strain release and pressure pulse being generated in the tubular string in response to displacement of the plug through the seat.

The disclosed jarring device generates two jarring impacts at the end points of a reciprocating hammer assembly. Initially, flow of pressurized fluid through the jarring device is obstructed by a deformable member. The resulting increase in fluid pressure upstream of the deformable member causes compression of a spring and downstream movement of the hammer assembly to generate a first jarring impact. A further increase in fluid pressure beyond a threshold, causes a release of the obstruction by either deforming the member or by slicing it by pushing it through a slicer. Releasing of the obstruction causes decompression of the spring, and upstream sliding of the hammer assembly to generate a second jarring impact.

A jarring device includes a housing, a mandrel received within the housing, and a pressure chamber defined between the housing and the mandrel and filled with a hydraulic fluid. A hydraulic lock piston is arranged about the mandrel and radially interposes the housing and the mandrel. The hydraulic lock piston includes a pressure piston having a first end exposed to the pressure chamber, a second end, and first and second fluid flowpaths defined in the pressure piston and extending axially between the first and second ends. When the mandrel moves in a first direction relative to the housing, the hydraulic fluid is metered through the first fluid flowpath and the second fluid flowpath is occluded. When the mandrel moves in a second direction relative to the housing and opposite the first direction, the hydraulic fluid is metered through the second fluid flowpath and the first fluid flowpath is occluded.

A method of dislodging a tubular string or well equipment connected to the tubular string can include connecting a dislodging tool in the tubular string, so that a flow passage of the dislodging tool extends through the tubular string, deploying a plug into the dislodging tool, applying a pressure differential across the plug, thereby displacing the plug through a seat of the dislodging tool, and dislodging the tubular string or the component in response to the displacing. A dislodging system can include a dislodging tool connected as part of a tubular string, the dislodging tool including a flow passage and a seat configured to sealingly engage a plug deployed into the tubular string, and at least one of a jarring force, load, impact, shock wave, elastic strain release and pressure pulse being generated in the tubular string in response to displacement of the plug through the seat.

A jarring apparatus includes first and second jarring assemblies rotatable relative to each other. A first impact surface is provided on the first jarring assembly and a second impact surface is provided on the second jarring assembly, wherein, in use, the first and second impact surfaces are biased together. A first lifting structure is rotatably fixed relative to the first jarring assembly and a second lifting structure is rotatably fixed relative to the second jarring assembly, the first and second lifting structures being configured to cooperate during relative rotation therebetween to cause cyclical relative displacement in one axial direction to define a lifting phase and relative displacement in a reverse axial direction to define a dropping phase. The first and second lifting structures are axially fixed relative to their associated jarring assembly during the lifting phase to provide axial separation between the first and second impact surfaces, and the second lifting structure is axially released relative to the second jarring assembly prior to initiation of the dropping phase to permit the first and second impact surfaces to be axially impacted together.

A jarring apparatus includes first and second jarring assemblies which are axially moveable relative to each other between first and second axial configurations, and a thrust assembly interposed between the first and second jarring assemblies to limit relative axial movement therebetween at the second axial configuration and permit axial loading in one axial direction to be transferred between the first and second jarring assemblies via the thrust assembly. The apparatus further includes a jarring mass axially moveable within the jarring apparatus in reverse first and second directions upon relative rotation between the first and second jarring assemblies.

A mechanical service tool that may include one or more anchors, a cutter, a communication and control system, and one or more sensors, as well as methods for operating the mechanical service tool, are provided. The one or more anchors may extend radially from the mechanical service tool and the cutter may move relative to the mechanical service tool. The cutter may include a drilling bit. The communication and control system may obtain remote commands that control the cutter, the one or more anchors, or both. The one or more sensors may detect operational conditions of the mechanical service tool and may be operatively coupled to the communication and control system.