Abstract: An externally actuatable tieback connector for establishing fluid communication and force resisting connection of a conduit to a subsea wellhead having an internal locking geometry. The tieback connector has a body structure that is adapted for landing on a wellhead, with a part thereof extending into the wellhead and carrying a split lock ring. A lock energizing element, moveable relative to the body structure, has a locking position expanding the lock ring into locking and pre-load force transmitting engagement with the internal locking geometry of the wellhead and an unlocking position releasing the tieback connector from the wellhead. One or more drive members extend from the lock energizing element and are exposed externally of the connector body and wellhead for engagement and actuating movement by a lock actuating tool such as a ROV or the like.

Abstract: A wellhead system for petroleum producing wells comprises a “stack-down” casing hanger configuration. In this stack-down system, the hanger for each successively smaller diameter casing string is landed or “nested” within the hanger for the next larger casing string. This approach allows the pack-off for each casing hanger to be retrieved independently, thus allowing fluid communication to be established with any of the casing annuli after all of the casing strings and hangers have been installed. Thus the pressure in each annulus may be monitored while the well is in production mode.

Abstract: An externally actuatable tieback connector for establishing fluid communication and force resisting connection of a conduit to a subsea wellhead having an internal locking geometry. The tieback connector has a body structure that is adapted for landing on a wellhead, with a part thereof extending into the wellhead and carrying a split lock ring. A lock energizing element, moveable relative to the body structure, has a locking position expanding the lock ring into locking and pre-load force transmitting engagement with the internal locking geometry of the wellhead and an unlocking position releasing the tieback connector from the wellhead. One or more drive members extend from the lock energizing element and are exposed externally of the connector body and wellhead for engagement and actuating movement by a lock actuating tool such as a ROV or the like.

Abstract: The concentric tubing completion system of the present invention comprises a surface Christmas tree which is located on a surface structure, a tieback connector which is secured to a mudline wellhead that is installed at the upper end of a subsea well bore, a mudline tubing hanger which is supported in the tieback connector, and a pair of concentric tubing strings which are suspended from corresponding tubing hangers in the surface Christmas tree and connected to the mudline tubing hanger. The annulus between the concentric tubing strings communicates with a number of passages in the mudline tubing hanger which are connected to the tubing annulus below the mudline tubing hanger. Thus, lift gas or other fluids may be communicated between the surface christmas tree and the tubing annulus through this annulus between the concentric tubing strings.

Abstract: A wellhead system for petroleum producing wells comprises a “stack-down” casing hanger configuration. In this stack-down system, the hanger for each successively smaller diameter casing string is landed or “nested” within the hanger for the next larger casing string. This approach allows the pack-off for each casing hanger to be retrieved independently, thus allowing fluid communication to be established with any of the casing annuli after all of the casing strings and hangers have been installed. Thus the pressure in each annulus may be monitored while the well is in production mode.

Abstract: The concentric tubing completion system of the present invention comprises a surface Christmas tree which is located on a surface structure, a tieback connector which is secured to a mudline wellhead that is installed at the upper end of a subsea well bore, a mudline tubing hanger which is supported in the tieback connector, and a pair of concentric tubing strings which are suspended from corresponding tubing hangers in the surface Christmas tree and connected to the mudline tubing hanger. The annulus between the concentric tubing strings communicates with a number of passages in the mudline tubing hanger which are connected to the tubing annulus below the mudline tubing hanger. Thus, lift gas or other fluids may be communicated between the surface christmas tree and the tubing annulus through this annulus between the concentric tubing strings.

Abstract: An adjustable tubular hanger for suspending a tubular string from a wellhead component is provided which includes an elongated body having a lower end adapted to be connected to the tubular string and an upper end portion including a plurality of axial annular grooves formed in the outer diameter surface thereof, each groove defining a downwardly facing support surface, and a support ring adapted to be positioned around the body in one of the grooves, the support ring having an upwardly facing load shoulder for engaging the support surface and a downwardly facing load surface for engaging a support shoulder formed in the wellhead component, whereby the elevation of the tubular hanger within the wellhead component can be adjusted depending on in which groove the support ring is positioned.

Abstract: An adjustable casing hanger for suspending a casing string from a wellhead is provided which includes an elongated tubular body having a lower end adapted to be connected to the casing string and an upper end portion including a plurality of axial annular grooves formed in the outer diameter surface thereof, each groove defining a downwardly facing support surface, and a support ring adapted to be positioned around the body in one of the grooves, the support ring having an upwardly facing load shoulder for engaging the support surface and a downwardly facing load surface for engaging a support shoulder formed in the wellhead, whereby the elevation of the casing hanger within the wellhead can be adjusted depending on in which groove the support ring is positioned.