Internal connection of tree to wellhead housing

摘要

A subsea wellhead assembly has a tree that connects internally to the bore of wellhead housing. The tree has a lower end that has a lock member that is moved radially outward into engagement with a profile in the bore of the wellhead housing. The tree is a monobore, having a production passage but no tubing annulus passage extending through it. The tubing hanger has a tubing annulus passage and a production passage. A valve is mounted in the tubing hanger for controlling flow through the tubing annulus passage.