| 摘要 |
Well tools comprising a go-devil actuated well safety valve, a locking assembly for releasably locking the safety valve at a desired depth in a well, running and pulling tools for installing and removing the safety valve, a go-devil ball for closing the safety valve, and apparatus for dropping the go-devil ball in a well under pressure and for retrieving the ball. The go-devil safety valve is mounted above the locking assembly and includes a trigger type latch which is released from above by the impact of the go-devil ball. The valve may be reset for reopening the valve without removal of the valve from the well bore by means of a special reset and pulling tool disclosed herein. The go-devil valve is installed in a well, preferably above a storm choke, to shut the well in under emergency conditions which releases the go-devil ball at the surface in response to hazardous conditions such as fire. The go-devil ball drops to the go-devil valve which closes in response to the impact of the ball.
|
