Question

In a horizontal subsea tree, which specific valve configuration allows for the retrieval of the tubing hanger without needing to pull the entire subsea tree to the surface?

Accepted Answer

In a horizontal subsea tree, the specific valve configuration that allows for the retrieval of the tubing hanger without pulling the tree is the use of an internal tubing hanger lockdown mechanism combined with a tubing hanger landing profile located within the tree body itself. A horizontal subsea tree is designed with a bore that runs vertically through the center, allowing the tubing hanger, which is the component that suspends the production tubing string inside the well, to be landed and locked directly into the tree housing rather than into the wellhead housing below the tree. Because the tubing hanger is landed inside the tree, the production tubing string can be pulled straight up through the tree bore by removing only the tree cap and the internal tree plug. The tree cap is the pressure-containing component that seals the top of the horizontal tree. By removing this cap and the internal tree plug, which is a temporary barrier installed in the tubing hanger to isolate the well, operators gain direct vertical access to the tubing hanger. The tubing hanger is then unlocked from the tree housing and retrieved to the surface through the open tree bore, leaving the main body of the subsea tree in place on the wellhead. This configuration separates the production tubing system from the tree structure, enabling well intervention or workover operations without disconnecting the subsea tree from the wellhead or disturbing the flowline connections.

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In a horizontal subsea tree, which specific valve configuration allows for the retrieval of the tubing hanger without needing to pull the entire subsea tree to the surface?