A system used to dislodge and, if necessary, sever a tubular string that is stuck within a cased wellbore. The system utilizes a jar, a plurality of plugs, and a tubular severance device. Components of the system are carried to their respective desired downhole positions by downward fluid flow within the wellbore. The jar is configured to jar the string in an effort to dislodge the string from its stuck point. The plugs are configured to fill open perforations formed in the casing in order to direct the fluid toward the stuck point and away from the perforations. If the string cannot be freed by the jar, the tubular severance device is deployed within the string above the stuck point. Detonation of the device severs the string above the stuck point.

A jarring tool includes a spring and a hydraulic piston cylinder arrangement for controlling the release of a mandrel to initiate a jarring force. The tool includes an adjustment mechanism for adjusting the minimum amount of an upward pulling force required to release the mandrel. The adjustment mechanism includes an axially adjustable trigger sleeve that cooperates with a dog clutch surrounding the mandrel.

A jarring tool includes a spring and a hydraulic piston cylinder arrangement for controlling the release of a mandrel to initiate a jarring force. The tool includes an adjustment mechanism for adjusting the minimum amount of an upward pulling force required to release the mandrel. The adjustment mechanism includes an axially adjustable trigger sleeve that cooperates with a dog clutch surrounding the mandrel.

A downhole oscillation tool includes a Moineau-type positive displacement pulse motor and a valve assembly for use in a drill string. The pulse motor includes a rotor configured to nutate within the bore of a stator. The rotor has at least two helical lobes that extend the length of the rotor, and the stator bore defines at least three helical lobes that extend the length of the stator. The valve assembly includes a first valve plate connected to the bottom end of the rotor and abuts the second valve plate to form a sliding seal. The second valve plate is fixedly coupled to the stator and remains stationary. First valve ports extend axially through the first valve plate, and second valve ports extend axially through the second valve plate. The first valve ports and second valve ports intermittently overlap as the first valve plate slides across the second valve plate to create pulses in the drilling fluid which is pumped through the tool to power the motor and valve assembly. The tool can generate pulses of different amplitudes and different wavelengths in each rotational cycle. The tool further includes a drop ball assembly configured to activate and deactivate the tool.

An apparatus includes a tubular, pressure sensors, expandable pads, a hydraulic chamber, and a computer system. The apparatus can be run in a wellbore. The apparatus is configured to detect whether the tubular is stuck within the wellbore. In response to determining that the tubular is stuck within the wellbore, the apparatus can determine a local of sticking of the tubular in the wellbore and can transmit a signal to the hydraulic chamber to pressurize one or more of the expandable pads, thereby causing the one or more expandable pads to expand and exert a force necessary to free the tubular.

An apparatus includes a tubular, pressure sensors, expandable pads, a hydraulic chamber, and a computer system. The apparatus can be run in a wellbore. The apparatus is configured to detect whether the tubular is stuck within the wellbore. In response to determining that the tubular is stuck within the wellbore, the apparatus can determine a local of sticking of the tubular in the wellbore and can transmit a signal to the hydraulic chamber to pressurize one or more of the expandable pads, thereby causing the one or more expandable pads to expand and exert a force necessary to free the tubular.

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 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 device for generating pressure waves in a well or a wellbore. The device includes a housing containing an impact-generating mechanism for generating the pressure waves and a connector for connecting the housing to a conveyor for transporting the device to any desired location within the well or the wellbore. The device may be used for a number of downhole applications such as cleaning perforations, fracturing processes, vibration of a casing to prevent fluid flow in a cemented annulus, hydraulic jar operations for freeing stuck downhole objects, generating data to optimize pumping parameters and as an enhancement to percussion drilling techniques.

A device for generating pressure waves in a well or a wellbore. The device includes a housing containing an impact-generating mechanism for generating the pressure waves and a connector for connecting the housing to a conveyor for transporting the device to any desired location within the well or the wellbore. The device may be used for a number of downhole applications such as cleaning perforations, fracturing processes, vibration of a casing to prevent fluid flow in a cemented annulus, hydraulic jar operations for freeing stuck downhole objects, generating data to optimize pumping parameters and as an enhancement to percussion drilling techniques.