| 摘要 |
<p>A control mechanism for use with a safety valve adapted to seal a wellbore is described. The control mechanism comprises at least one valve actuator for engaging with the safety valve, the at least one actuator being moveable, in use, between a valve open position in which the safety valve is open and a valve closed position, in which the safety valve is closed. The control mechanism further comprises biasing apparatus adapted to bias the at least one valve actuator to the valve closed position, wherein, in use, the at least one valve actuator extends from the safety valve up to a wellbore wellhead. In one described embodiment, the safety valve is moved between the open and closed positions by movement of the at least one valve actuator with respect to the wellbore.</p> |
