A release mechanism for a jarring tool is formed by a plurality of segmented release lugs. Each lug includes a plurality of axial spaced projections on an inner surface and a plurality of grooves on an outer surface. The projections have either different widths or are separated by varying distances and releaseably engage corresponding grooves in a mandrel located within a housing of the tool. The release lugs are positioned between a trigger sleeve and the mandrel.

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 drilling jar in an oil and gas drilling operation or fishing operation includes a control unit having one or more transceivers configured to communicate wirelessly with a surface control unit. The control unit is configured to receive an activation signal from the surface control unit, and cause to activate the drilling jar in response to the activation signal. The wireless transceivers may communicate using any wireless communication technology, including but not limited to Wi-Fi, Wi-Fi Direct, and BLE. A method for operating a drilling jar includes receiving, by a control unit comprising one or more transceivers configured to communicate wirelessly with a surface control unit, an activation signal from the surface control unit, and causing to activate the drilling jar in response to the activation signal.

An apparatus and method for drilling is disclosed, including a drill string with at least one jar and one reaction valve. Drilling fluid flows through the reaction valve. The reaction valve is selectively throttled, which creates a differential pressure across the valve seat. The differential pressure creates an axial force that is transferred to the jar, which aids in cocking or firing the jar. In an embodiment, a reaction valve throttles downward fluid flow to create a downward compressional force on the jar, while in another embodiment, a reaction valve throttles upward fluid flow to create an upward tensile force on the jar. Upward and downward fluid flow may be alternatively throttled for alternately firing the jar upwards and downwards. A bypass valve may be included in the drill string for establishing a drilling fluid flow path when such may be otherwise obstructed by foreign matter in the wellbore.

A hydraulic jar for delivering impacts downhole. The jarring mechanism includes a cup-type piston that moves through a seal bore. The cup is deformable in response to fluid pressure so that it expands each time it moves through the seal bore to compensate for wear on the lip. Since only minimum interference is required between the piston and seal bore, less material may be used. This reduces the force required to reset the tool, which is particularly advantageous in horizontal wells. The seal bore may be slightly wider at the exit; the cup expands to this exit diameter, ensuring an interference fit as the cup travels back through the smaller diameter entry section. The entry end of the seal bore may include longitudinal grooves. This prevents the piston cup from rupturing by preventing a fluid seal around the lip until the most of cup is inside the seal bore.

A modular reamer shoe for connection to an end of a tubular structure, such as a casing or liner, for deployment in a wellbore includes a body configured for connection to the tubular structure (casing or liner). The body includes a first section and an adjacent second section. The first section is connected to the second section such that torque can be transmitted between the first section and the second section. The first section defines a starter reamer defined by a plurality of first cutting elements and second cutting elements spaced from the first cutting elements. The reamer shoe has a plurality of actuatable blades disposed within the second area of the first section. The plurality of blades moves between extended positions and retracted positions. A nose is connected to the first section of the body. The second section is actuatable and can move in an axial direction so as to move the body, including the nose, in forward/rearward directions.

An apparatus and method for drilling is disclosed, including a drill string with at least one jar and one reaction valve. Drilling fluid flows through the reaction valve. The reaction valve is selectively throttled, which creates a differential pressure across the valve seat. The differential pressure creates an axial force that is transferred to the jar, which aids in cocking or firing the jar. In an embodiment, a reaction valve throttles downward fluid flow to create a downward compressional force on the jar, while in another embodiment, a reaction valve throttles upward fluid flow to create an upward tensile force on the jar. Upward and downward fluid flow may be alternatively throttled for alternately firing the jar upwards and downwards. A bypass valve may be included in the drill string for establishing a drilling fluid flow path when such may be otherwise obstructed by foreign matter in the wellbore.

A release mechanism for a jarring tool is formed by a plurality of segmented release lugs. Each lug includes a plurality of axial spaced projections on an inner surface and a plurality of grooves on an outer surface. The projections have either different widths or are separated by varying distances and releaseably engage corresponding grooves in a mandrel located within a housing of the tool. The release lugs are positioned between a trigger sleeve and the mandrel.

A release mechanism for a jarring tool is formed by a plurality of segmented release lugs. Each lug includes a plurality of axial spaced projections on an inner surface and a plurality of grooves on an outer surface. The projections have either different widths or are separated by varying distances and releaseably engage corresponding grooves in a mandrel located within a housing of the tool. The release lugs are positioned between a trigger sleeve and the mandrel.