Self-discharge check valve special for oil extraction rodless pump of high sand content oil well

Abstract

The invention relates to a special self-draining check valve for a non-rod pump for oil production in a high-sand oil well. The utility model mainly solves the problem that when the downhole oil production rodless pump unit of the existing valve body is shut down, sand accumulates at the outlet of the pipe string, which makes it difficult to start the unit again. It is characterized in that: there is an external oil drain hole on the middle and upper wall of the valve body, and a positioning step is provided in the middle of the inner wall; there is a valve core assembly that can move up and down in the valve body, the upper end of the valve core assembly is an oil drain hole part, and the lower end It is the part of the oil inlet hole, and there is a spring in the ring cavity of the spool assembly and the valve body; when the unit starts, the spool moves up, the oil inlet hole opens and communicates with the oil pipe string; when the unit stops, the spool assembly It moves down under the action of the oil inlet passage, and at the same time opens the upper oil drain hole, and the sand accumulated in the tubing string is automatically discharged into the oil casing annulus. The valve can realize the two functions of one-way flow of liquid and automatic oil drainage, so that the sand accumulation in the oil pipe can be fully discharged when the downhole oil production rodless pump unit stops, and it is convenient for the unit to start up again.

Description

technical field [0001] The invention relates to a valve body in a lifting device used in the field of oil production in oil fields, in particular to a self-draining single-flow valve specially used for a rodless pump for oil production in high-sand oil wells. Background technique [0002] With the continuous deepening of oil exploitation, various geological conditions are becoming more and more complex, and the corresponding oil recovery technology is also constantly developing to meet the needs of different geological conditions. At present, rodless pump units for downhole oil production, such as electric submersible pumps and screw pumps, generally have two parts at the outlet: a check valve and an oil drain valve. To the ground, when the unit is shut down, the oil drain valve spool is broken open by dropping the hand to make the well fluid in the tubing string flow out from the oil drain hole, and the two valves work independently. When the unit is working in a sand-cont...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem of existing check valve and oil drain valve when the downhole oil production rodless pump unit shuts down, sand accumulates at the outlet of the pipe string, making it difficult to start the unit again, the present invention provides a high sand content oil well production rodless pump Special self-drain check valve

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