| 摘要 |
<p>"A CHECK VALVE FOR FLUID-PRODUCING WELLS" A check valve is provided for use in the tubing string of a fluid producing well. The check valve is removably seated within the restricted diameter of a seating nipple in the tubing string. Resilient holddown means at the base of the valve are provided for this purpose. The check valve comprises a hollow generally tubular body having a pierceable valve element positioned therein, the valve opens and closes in response to fluid pressures bearing thereon. To equalize the pressures above and below the valve the pierceable valve element may be ruptured by a conventional wireline spear, allowing the fluid to drain slowly through the valve.</p> |
