Patent ID: 7216699

Claim:
A subsea wellhead assembly, comprising: a lower section of outer casing extending into a well to a selected depth, the lower section of outer casing having an upper end located within the well below a sea floor; an outer tubular member secured to the upper end of the lower section of outer casing and having a bore containing a grooved profile; an inner tubular member that lands within the outer tubular member; an upper section of outer casing located in the well and having a lower end secured to the inner tubular member; a subsea wellhead housing secured to an upper end of the upper section of outer casing and protruding above the sea floor; a locking member carried by the inner tubular member that moves between a locked and unlocked position relative to the grooved profile to lock the inner tubular member to the outer tubular member; an axially moveable, hydraulically actuated locking sleeve carried within the inner tubular member that slidingly engages the locking member for selectively camming the locking member between the locked and unlocked positions; and a hydraulic fluid passage extending from the locking sleeve to supply hydraulic fluid to move the locking member to the unlocked position, allowing the wellhead housing, the upper section of outer casing and the inner tubular member to be withdrawn from the well in the event of abandonment of the well.