An assembly disposed within a subterranean wellbore can include a first dislodging tool coupled to a bottom end of a tubing string, wherein the first dislodging tool, when enabled at a first time, performs a first action to free at least one service tool, disposed below the first dislodging tool in the subterranean wellbore, from being stuck.

A drilling assembly includes a drill string configured to be disposed within a wellbore. The drilling assembly also includes a sub fluidically coupled to the drill string. The sub includes a mandrel fixed to the drill string and defines an external helically undulated surface and a bore configured to flow drilling fluid received from the drill string. The sub includes a sleeve rotationally coupled to and disposed outside the mandrel. The sleeve has an internal helically undulated surface corresponding with the external helically undulated surface of the mandrel to form, with the mandrel, a progressive cavity. The progressive cavity receives fluid from the bore of the mandrel to rotate the sleeve as the drilling fluid flows along the cavity. The sub also includes a valve configured to regulate a flow of the drilling fluid along the bore to direct fluid toward or away from the progressive cavity.

An assembly disposed within a subterranean wellbore can include a first dislodging tool coupled to a bottom end of a tubing string, wherein the first dislodging tool, when enabled at a first time, performs a first action to free at least one service tool, disposed below the first dislodging tool in the subterranean wellbore, from being stuck.

A drill pipe assembly has an inner tubular member with a Trojan central bore. An outer tubular member circumscribes the inner tubular member. An annular storage space is defined between the outer tubular member and the inner tubular member. An uphole connection member connects to an uphole drill string so that the Trojan central bore is in communication with the uphole drill string. A downhole connection member connects to a downhole drill string so that the Trojan central bore is in communication with the downhole drill string. A window assembly is moveable between a closed position and an open position. In the open position the window assembly provides a flow path between the annular storage space and an outside of the outer tubular member. In the closed position the window assembly prevents a flow between the annular storage space and the outside of the outer tubular member.

A propulsion tool for delivering a tubing into a subterranean well for performing a downhole operation includes a tool housing, the tool housing being a tubular shaped member. A connector system is operable to secure the propulsion tool to the tubing. A jet assembly extends from an internal cavity of the tool housing to an outside of the tool housing and is oriented in an uphole direction. A jet inner flow path is located within the tool housing. The jet inner flow path is oriented to selectively direct a flow of fluid from the tubing in a direction towards the jet assembly.

A propulsion tool for delivering a tubing into a subterranean well for performing a downhole operation includes a tool housing, the tool housing being a tubular shaped member. A connector system is operable to secure the propulsion tool to the tubing. A jet assembly extends from an internal cavity of the tool housing to an outside of the tool housing and is oriented in an uphole direction. A jet inner flow path is located within the tool housing. The jet inner flow path is oriented to selectively direct a flow of fluid from the tubing in a direction towards the jet assembly.

Systems and methods for unsticking a tubular string in a subterranean well that is a stuck pipe include securing a circulation sub to an uphole end of the tubular string outside of the subterranean well. The buoyancy of the tubular string is increased by delivering a replacement fluid through the circulation sub and into a bore of the tubular string. The replacement fluid displaces an operating fluid located within the bore of the tubular string. A density of the replacement fluid is less than a density of the operating fluid. Conventional operations for unsticking the tubular string can be performed. The replacement fluid in the bore of the tubular string can be replaced with the operating fluid, and the replacement fluid can be delivered back out of the subterranean well.

Systems and methods for unsticking a tubular string in a subterranean well that is a stuck pipe include securing a circulation sub to an uphole end of the tubular string outside of the subterranean well. The buoyancy of the tubular string is increased by delivering a replacement fluid through the circulation sub and into a bore of the tubular string. The replacement fluid displaces an operating fluid located within the bore of the tubular string. A density of the replacement fluid is less than a density of the operating fluid. Conventional operations for unsticking the tubular string can be performed. The replacement fluid in the bore of the tubular string can be replaced with the operating fluid, and the replacement fluid can be delivered back out of the subterranean well.

A method and apparatus for single-trip casing cutting and pulling for well abandonment and slot recovery. Perforations (28) are made in the casing (12) at a maximum depth using a punch tool (18) and fluid circulated through the perforations to determine a return at surface. In the event of a return at surface being detected, the casing (12) is cut and pulled. When no return is detected, perforations are made at increasingly shallower depths until a return is detected and the casing (12) is then cut and pulled. This ensures the maximum length of casing (12) is cut and pulled on a single trip in the well bore (10).

A diffuser assembly is provided, comprising a diffuser adapted to reside within a conduit, having an upper member mountable within the conduit and having a fluid inlet port, and a lower section having a diffuser screen; a plurality of stationary diffusing members below the fluid inlet port, wherein the diffusing members are radially oriented relative to a central axis of the diffuser; and (c) a centralizing member above the diffuser screen having a diameter greater than the diffuser screen. The diffuser screen is a cylinder having a plurality of diffuser slots formed therein and a bottom cap having a fluid port; and each of the plurality of diffusing members extends substantially parallel to the central axis.