Kit and method for modification of a horizontal valve tree

A kit for modifying an existing horizontal valve tree to work as a monobore vertical valve tree, the kit provides a modified tubing hanger configuration to facilitate pulling the horizontal valve tree without first having to pull a connected upper well completion that comprises an original, first tubing hanger that is fastened in a center passage in the horizontal valve tree, wherein the kit comprises:

• a tubing hanger top to replace the original, first tubing hanger,
• a second tubing hanger, and
• a tubing hanger adapter, wherein
• the tubing hanger top is provided with communication paths that correspond to communication paths in systems arranged downstream in or by the horizontal valve tree,
• the second tubing hanger is provided with communication paths for communicating with downhole installations in a well,
• the tubing hanger adapter comprises devices that are arranged for coupling the tubing hanger adapter with the tubing hanger top and the second tubing hanger, as well as communication paths arranged for coupling the communication paths of the tubing hanger top with the corresponding communication paths of the second tubing hanger.