| 摘要 |
<p>A subsurface safety valve has a tubular valve housing, a valve closure member movable between an open and a closed position, an axially shiftable flow tube for opening the valve closure member, a spring for biasing the flow tube to a closed position, a piston and cylinder assembly to move the flow tube to an open position, and a plug inserted within an opening in the valve housing. This opening is in fluid communication with the piston and cylinder assembly. The plug is adapted to be displaced from the opening to lock out the safety valve, and to establish secondary hydraulic fluid communication with an interior of the safety valve in order to operate secondary tools, such as wireline set secondary valves, inserted into the locked out safety valve.</p> |
