social sub surface safety valve

摘要

A subsurface safety valve for wells, including a ball valve closed by well fluid pressure and opened by control fluid pressure supplied from the surface. The subsurface valve includes a control fluid pressure responsive balancing valve for equalizing pressure across the closed ball valve to relieve the ball valve seating pressure. The ball valve is rotatable by support pins and is also slightly axially movable in its support. A sealing and operating sleeve below the ball valve is spring loaded upwardly. One of more additional springs are incorporated above the ball valve to assist in overcoming hydrostatic pressure in the control tubing. The subsurface valve assembly is incorporated in a production tubing string or is removably received in a seating nipple so as to be wireline retrieveable.