| 摘要 |
A lost-motion valve actuator which provides the ability to run a tool bore closure valve in a testing string into a well in an open mode, apply pressure to the well annulus surrounding the string without cycling the valve, thereafter reduce pressure, closing the valve subsequent to the initial pressure increase, and subsequently opening the valve with pressure increases and closing it with pressure decreases, thus permitting the tool bore closure valve to subsequently respond in a normal manner (open on pressure increase, close on pressure decrease) to pressure changes in the annulus subsequent to the first pressure increase/decrease cycle. |
