Downhole hollow oil well pump

Abstract

The invention discloses a downhole hollow oil well pump. The downhole hollow oil well pump comprises a barrel body, wherein a hollow piston rod anchored down a well is arranged inside the barrel body; an upstream end of the piston rod is closed; a downstream end of the piston rod is provided with a well fluid inlet; a sealing sleeve fixed to the barrel body sleeves the piston rod; the sealing sleeve and a sealing structure of the piston rod divide an inner cavity of the barrel body into an upper chamber, a middle sealing chamber and a lower chamber; first oil introduction holes connected with the middle sealing chamber are formed in the side wall of the piston rod; the first oil introduction holes are coated with first elastic sealing parts; second oil introduction holes connected with the middle sealing chamber and a space outside the barrel body are formed in the sealing sleeve; and the second oil introduction holes are coated with second elastic sealing parts. According to the downhole hollow oil well pump, simulated production can be achieved, a stable working condition is reached, a testing tool is controlled through lifting and putting down a continuous oil pipe to test capacity conditions of all layers, a good sealing property is achieved, inner diameters are sufficiently guaranteed under the condition that outer diameters are the same, and the downhole hollow oil well pump is particularly applicable to production testing of high-inclination wells and horizontal wells.

Description

technical field [0001] The invention relates to the field of supporting tools for oil layer testing in oil fields, in particular to an underground hollow oil well pump. Background technique [0002] During the dynamic production test of the oil well, the downstream end of the hollow oil well pump is connected to the anchor and the packer, and the upstream end is connected to the tubing. The hollow oil well pump works by lifting and releasing, simulating the normal pumping production of the oil layer. In the simulated production process, the test cable is run in the oil pipe, and the cable is generally run in through the coiled tubing. The test instrument tests the production capacity of each layer during the working process of the hollow oil well pump. Especially in the test process of highly deviated wells and horizontal wells, this process has been approved by the production unit. [0003] At present, ball pump valves are used as fixed and floating valves in hollow oil we...

AI Technical Summary

Problems solved by technology

[0003] At present, ball pump valves are used as fixed and floating valves in hollow oil well pumps. However, since hollow oil well pumps need to be connected to coiled tubing during work, the minimum internal diameter of hollow oil well pumps is required to be as large as possible. The casing restricts the outer diameter of the hollow oil well pump. When both the inner and outer diameters are limited, the ball size of the ball pump valve is too small, which is greatly affected by sand particles, especially in the horizontal well section where there is a problem of ball reset lag.

If a steel ring valve is used, there is a problem of poor sealing, and the speed of lifting and releasing the tubing is slow. When the leakage of the ring valve is serious, the wellhead will not produce fluid

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