An impact generator includes a housing having an uphole end and a downhole end and defining a chamber therein between the uphole and downhole ends. A mandrel is movably arranged at least partially within the chamber between an engaged configuration and a disengaged configuration, and a top sub is coupled to the housing at the uphole end and has an upper core extension arranged at least partially therein. The upper core extension is configured to move between a fixed position, where the mandrel is maintained in the engaged configuration, and an unfixed position, where the mandrel is able to move to the disengaged configuration. An impact tool is coupled to a distal end of the mandrel to deliver an impact force to a downhole obstruction when the mandrel is moved to the disengaged configuration.

An impact generator includes a housing having an uphole end and a downhole end and defining a chamber therein between the uphole and downhole ends. A mandrel is movably arranged at least partially within the chamber between an engaged configuration and a disengaged configuration, and a top sub is coupled to the housing at the uphole end and has an upper core extension arranged at least partially therein. The upper core extension is configured to move between a fixed position, where the mandrel is maintained in the engaged configuration, and an unfixed position, where the mandrel is able to move to the disengaged configuration. An impact tool is coupled to a distal end of the mandrel to deliver an impact force to a downhole obstruction when the mandrel is moved to the disengaged configuration.

An apparatus for coupling between opposing first and second portions of a downhole tool string. The apparatus includes a housing having a port therein, a shaft extending within at least a portion of the housing, and a flow restrictor reducing a flow area of the port. The housing and the shaft move axially relative to each other. The port fluidly connects a space external to the housing with an annulus defined between the housing and the shaft.

An apparatus for coupling between opposing first and second portions of a downhole tool string. The apparatus includes a housing having a port therein, a shaft extending within at least a portion of the housing, and a flow restrictor reducing a flow area of the port. The housing and the shaft move axially relative to each other. The port fluidly connects a space external to the housing with an annulus defined between the housing and the shaft.

The invention is directed to a novel and useful fluid-tight, metal-to-metal, annular seal which can be repeatedly cycled in a high temperature, high pressure environment. More specifically, the invention provides a metal-to-metal, annular, seal on a radially expandable sliding sleeve which moves longitudinally from a reduced ID section of a bore to an enlarged section of the bore. The seal is disengaged at the enlarged bore section resulting in rapid fluid flow and pressure equalization which would destroy many traditional elastomer seals.

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 may have either different widths or may be 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. In one embodiment, the release lugs are positioned within a support collar. In a second embodiment, the lugs are provided with stabilizing posts and cavities that serve to maintain the lugs in a proper alignment.

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 may have either different widths or may be 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. In one embodiment, the release lugs are positioned within a support collar. In a second embodiment, the lugs are provided with stabilizing posts and cavities that serve to maintain the lugs in a proper alignment.

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. The release lugs may be supported by an annular ring member.

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. The release lugs may be supported by an annular ring member.

A method of freeing a stuck pipe includes positioning a pipe freeing tool within the wellbore at a location proximate the stuck pipe, the pipe freeing tool including a downhole conveyance; and an arm coupled to the downhole conveyance, and activating the arm of the pipe freeing tool to apply a force to an external surface of the stuck pipe, wherein the force moves the stuck pipe away from a surface of the wellbore and towards a center of the wellbore. Another method of freeing a stuck pipe from a wellbore includes positioning a pipe freeing tool within the wellbore at a location proximate the stuck pipe, the pipe freeing tool including a jack device and a set of wheels coupled to the jack device, and activating the jack device of the pipe freeing tool to apply a force to an external surface of the stuck pipe.