Valve assembly for controlling liquid flow in a we

专利名称：Valve assembly for controlling liquid flow in

a wellbore

发明人：Onazip J. Fournier申请号：US05/877443申请日：19780213公开号：US04154303A公开日：19790515

摘要：The valve assembly disclosed herein is used primarily in oil or gas well servicingto prevent contamination of fluids used to treat the formation. The valve is coupled intoa tubing string, and it includes a slidable hollow mandrel, with a hingable flapper diskpositioned below the mandrel. The valve is generally used in cooperation with a packertool and bridge plug. When treating fluid is pumped down the tubing string it pushes theflapper disk open and holds it open, so the fluid can reach the formation interval beingtreated. To treat the next higher interval the packer is unset to raise the tubing string.Releasing the packer allows residual fluids to backflow from the well casing annulus intothe tubing string. In this tool the backflowing fluid closes the flapper, so that it acts as acheck valve to prevent contamination of the treating fluid. Before the valve is pulled outof the casing the mandrel is slid downwardly, to push the flapper open and hold it inopen position.

申请人：DOW CHEMICAL CO THE

代理人：V. Dean Clausen

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