A tool to remove portions of casing from a wellbore. A tool may include a bottom sub-assembly and casing that selectively detach from a sub-assembly. This may allow for tools and casing within the wellbore to be efficiently and effectively removed from the wellbore without having to cut tools down well.

A method of deploying a jointed tubular string into a subsea wellbore includes lowering the tubular string into the subsea wellbore from an offshore drilling unit. The tubular string has a slip joint. The method further includes, after lowering, anchoring a lower portion of the tubular string below the slip joint to a non-heaving structure. The method further includes, while the lower portion is anchored: supporting an upper portion of the tubular string above the slip joint from a rig floor of the offshore drilling unit; after supporting, adding one or more joints to the tubular string, thereby extending the tubular string; and releasing the upper portion of the extended tubular string from the rig floor. The method further includes: releasing the lower portion of the extended tubular string from the non-heaving structure; and lowering the extended tubular string into the subsea wellbore.

A method of deploying a jointed tubular string into a subsea wellbore includes lowering the tubular string into the subsea wellbore from an offshore drilling unit. The tubular string has a slip joint. The method further includes, after lowering, anchoring a lower portion of the tubular string below the slip joint to a non-heaving structure. The method further includes, while the lower portion is anchored: supporting an upper portion of the tubular string above the slip joint from a rig floor of the offshore drilling unit; after supporting, adding one or more joints to the tubular string, thereby extending the tubular string; and releasing the upper portion of the extended tubular string from the rig floor. The method further includes: releasing the lower portion of the extended tubular string from the non-heaving structure; and lowering the extended tubular string into the subsea wellbore.

Method and apparatus for removing a downhole casing from a well on a single trip. A downhole tool assembly is arranged on a work string having a downhole pull tool, a spear tool, motor unit and cutting device. The downhole pull tool is set inside a first casing string and the spear tool, motor unit and cutting device are located inside a second casing string, located through the first casing string. The downhole pull tool and spear tool can be configured to grip the respective casings during cutting of the second casing string. The cut casing section can then be pulled using the downhole pull tool to dislodge the casing section, whereupon via attachment to the spear tool, the cut casing section can be removed from the well. The assembly can be re-set at shallower depths in the event that the cut casing section cannot be dislodged for removal.

Method and apparatus for removing a downhole casing from a well on a single trip. A downhole tool assembly is arranged on a work string having a downhole pull tool, a spear tool, motor unit and cutting device. The downhole pull tool is set inside a first casing string and the spear tool, motor unit and cutting device are located inside a second casing string, located through the first casing string. The downhole pull tool and spear tool can be configured to grip the respective casings during cutting of the second casing string. The cut casing section can then be pulled using the downhole pull tool to dislodge the casing section, whereupon via attachment to the spear tool, the cut casing section can be removed from the well. The assembly can be re-set at shallower depths in the event that the cut casing section cannot be dislodged for removal.

A downhole release tools, systems, and methods are described. The tool configured to release a string in a wellbore includes: a cylindrical body with an uphole end defining a first set of internal threads and a downhole end defining a second set of internal threads; a sensor operable to measure strain in the cylindrical body, a magnetic field, or both; a release joint with an uphole end defining a first set of external threads and a frustoconical downhole end defining a second set of external threads, the release joint attached to the cylindrical body by engagement between the first set of external threads of the release joint and the second set of internal threads of the cylindrical body; safety pins rotationally fixing the release joint in position relative to the cylindrical body; and a drive system operable to rotate the release joint relative to the cylindrical body.

Provided, in one embodiment, is a pulling prong. The pulling prong, in one example, includes an outer housing, and a nose assembly slidably located within the outer housing. In this example, the nose assembly and outer housing form an activation chamber. The pulling prong, in this example, may further include activation means located within the activation chamber, the activation means configured to move the nose assembly from a first running configuration to a second retrieving configuration.

Provided, in one embodiment, is a pulling prong. The pulling prong, in one example, includes an outer housing, and a nose assembly slidably located within the outer housing. In this example, the nose assembly and outer housing form an activation chamber. The pulling prong, in this example, may further include activation means located within the activation chamber, the activation means configured to move the nose assembly from a first running configuration to a second retrieving configuration.

A convertible fishing tool is provided for removing an object (fish) from a wellbore. The fishing tool includes an elongated hollow main housing and a plurality of slip blades that are disposed distal to the main housing and move radially between fully retracted positions and fully extended positions. In the fully retracted positions, the fishing tool is in spear configuration and in the fully extended positions, the fishing tool is in an overshot configuration. The fishing tool also includes an actuation system configured to move the plurality of slip blades in a radial direction between the fully retracted positions and the fully extended positions.

A convertible fishing tool is provided for removing an object (fish) from a wellbore. The fishing tool includes an elongated hollow main housing and a plurality of slip blades that are disposed distal to the main housing and move radially between fully retracted positions and fully extended positions. In the fully retracted positions, the fishing tool is in spear configuration and in the fully extended positions, the fishing tool is in an overshot configuration. The fishing tool also includes an actuation system configured to move the plurality of slip blades in a radial direction between the fully retracted positions and the fully extended positions.