| 摘要 |
<p>SURFACE CONTROLLED SUBSURFACE SAFETY VALVE Disclosed is a surface controlled subsurface safety valve adapted to be landed in a dual line landing nipple. The safety valve is used to control well fluids conducted through the bore of a well tubing string. The valve has a control fluid pressure chamber and a balance pressure chamber along with a zone in the valve exposed to balance fluid pressure. The control fluid pressure chamber is interspersed between the balance fluid pressure chamber and the balance pressure zone, and has a system of seals associated therewith, that provide a fail-closed safety system. Tubing bore pressure, in the event of seal failure, enters the balance pressure chamber, causing the safety valve to close. This abstract of the disclosure is neither intended to define the scope of the invention which, of course, is measured by the claims nor is it intended to limit the invention in any way.</p> |
