SIMPLIFIED XMAS TREE USING SUB-SEA TEST TREE

摘要

An improved sub-sea xmas tree (10) is disclosed which consists of a wellhead connector (12), a cylindrical structural housing (14) and a tree cap (16) mounted on top of the housing (14). A dual bore sub-sea completion test tree (20) is disposed in the housing (14) and it has a main production bore (22) with series ball valves (26, 28) for controlling fluid flow in the productio n flow path and an annulus bore (24) with a ball valve (30) therein. The ball valves are independently and remotely actuatable by a remotely operated vehicle (ROV) override system to control communication through the xmas tree (10) and to comply with various regulatory standards. A cross-over valve (82 ) is provided between the main bore (22) and the annulus bore (24) to allow fluid passage for well kill operations.