PRODUCTION TUBING DRAIN VALVE

摘要

A tubing drain valve in a production tubing string, positioned above a pump, is operated to open drain ports in the housing for draining produced fluids from the production tubing when the pump is shut off. The drain valve incorporates a check valve assembly which is freely moveable within the drain valve to shift a sleeve to open and close the drain ports. An uphole end of the check valve assembly is above the sleeve and seals to the top of a sleeve to shift the sleeve downhole and open the drain ports. A downhole end of the check valve is positioned below the sleeve in the valve. When the pump is turned on, the downhole end of the check valve assembly moves uphole to seal to the sleeve, creating a positive force to lift the sleeve to block the drain ports. The produced fluids flow through the valve and the production tubing to surface. The positive force minimizes the effect of fouling of the valve due to debris above the valve which might otherwise result in failure to shift the sleeve uphole, leaving the drain ports open.