Safety valve utilizing an isolation valve

摘要

A safety valve (100) for use in a well bore having an annulus. The valve (100) comprises a tubular valve housing having a valve closure member (132) captured therein and movable between an open and a closed position. An axially shiftable opening prong (130) is also captured in said housing for opening the valve closure member (132). A control line (104) is provided for supplying a hydraulic pressure to move the opening prong (130) against the closure member (132). A balance line (106) coupled to said tubular housing, and an isolation valve (108) coupled to said balance line (106). <IMAGE> <IMAGE>