Abstract: Apparatus and method for isolating an annular bore below a tubing hanger body disposed in a wellhead assembly. The hanger body is characterized by at least two annulus flowby passages that are capable of fluid communication with areas outside the hanger body through the central bore of the hanger body. An integral valve piston is disposed within the central bore of the hanger body, and is operable to axially displace within the central bore between a closed and opened position. The displacement of the piston is caused by the alternating introduction of pressurizing fluid into separate actuation chambers. In the closed position, the piston is positioned so that at least one of the flowby passages is sealingly engaged in a manner that prevents fluid flow through the hanger body from outside sources such as an annulus bore located below the hanger body.

Abstract: Apparatus and method for isolating an annular bore below a tubing hanger body disposed in a wellhead assembly. The hanger body is characterized by at least two annulus flowby passages that are capable of fluid communication with areas outside the hanger body through the central bore of the hanger body. An integral valve piston is disposed within the central bore of the hanger body, and is operable to axially displace within the central bore between a closed and opened position. The displacement of the piston is caused by the alternating introduction of pressurizing fluid into separate actuation chambers. In the closed position, the piston is positioned so that at least one of the flowby passages is sealingly engaged in a manner that prevents fluid flow through the hanger body from outside sources such as an annulus bore located below the hanger body.

Abstract: A retrievable tree cap for use on a subsea tree having a concentric bore. The tree cap may be installed and retrieved using a remotely operated vehicle. Hydraulic pressure may be used to lock the tree cap onto the subsea tree and to set the tree cap seals. The tree cap is locked onto the subsea tree before setting the seals within the concentric bore. The tree cap includes a locking means that may engage a profile within the subsea tree regardless of the radial orientation of the tree cap. The tree cap may be used to hydraulically isolate an annulus bore from the production bore of the subsea tree. The tree cap may provide for the injection of a corrosion inhibitor within a cavity of the tree cap and may also provide for the removal of water trapped between the tree cap and the subsea tree.

Abstract: Subsea oil and gas production methods and apparatus and, more particularly, a tubing hanger design for facilitating the control of downhole hydraulic and electrical controls while running the tubing hanger. The tubing hanger may include means for switching hydraulic and/or electrical controls to a side penetrator before the hanger is landed in a tree body. The hanger may include alignment means to ensure proper positioning of hanger prior to landing in a casing. The present disclosure of a method of soft landing a tubing hanger to provide better control prior to landing in the tree body.