Patent ID: 7219741

Claim:
In a subsea well assembly having a tubular member located subsea at an upper end of the well, a tubing hanger landed in the tubular member, the tubing hanger connected to a string of tubing extending into the well, the tubing hanger having a production passage for flowing production fluid from the well, the tubing hanger having a tubing annulus passage in communication with a tubing annulus surrounding the tubing, the improvement comprises: a tubing annulus valve located in the tubing annulus passage, the tubing annulus valve having an axially movable member adapted to be moved from a closed position to an open position; a releasable retention device that prevents movement of the movable member from the closed position to the open position; a hydraulically driven engaging tool mounted exterior of the tubing hanger that selectively moves axially to release the retention device to move the movable member from the closed position to the open position; and a releasable lock member that selectively locks the engaging tool to the movable member, allowing the engaging tool to move the movable member from the open position back to the closed position.