Hydraulic oil pump

Abstract

A hydraulic oil pump realizes automatic switch by depending the oil well liquid provided by ground pump station as power liquid. The pump includes an upper joint, a pump housing, a switch valve, a control mechanism, a drive cylinder, an upper discharge suck valve assembly, a hollow piston rod, a liquid discharging cylinder, a lower discharge suck valve assembly and a lower joint. Two different opening loops can be adopted according to different well conditions; each loop has four implementing schemes. The effect is that: the pump thoroughly changes the control mode that the switch valve and drive cylinder moves synchronously in conventional water power piston pump, the switch valve is at non-friction state in most time, and the sealing surface will not bearing erosion during switch process. Therefore, the pump has strong reliability and low requirement for power liquid quality, and has a power consumption which is only 25-30% of existing oil pump; thereby it is perfect equipment for oil extraction from inclined well, deep well and dense oil well.

Description

Technical field: [0001] The invention relates to the technical field of petroleum rodless oil production, in particular to a hydraulic oil well pump which relies on a surface pump station to provide power fluid and realizes automatic reversing underground. technical background [0002] Conventional beam pumping units have low efficiency, but they have always occupied a dominant position in the field of oil extraction for many years because of their reliable performance and convenient management. With the rapid development of directional wells and horizontal wells technology, and oilfields entering the late stage of oil production, the viscosity of crude oil increases, water cut increases, sand production increases, and the liquid level of oil wells decreases, making oil recovery more difficult year by year. Rod pumps driven by conventional beam pumping units cannot adapt to directional wells, horizontal wells, and oil wells in the later stage of oil production. The efficien...

AI Technical Summary

Problems solved by technology

Rod pumps driven by conventional beam pumping units cannot adapt to directional wells, horizontal wells, and oil production in later stages of oil well production.

The efficiency of the conventional pumping unit drops to less than 20% due to the friction between the sucker rod and the tubing in the production of inclined wells; what is more serious is that the sucker rod breaks off or the tubing wears and leaks due to the eccentric wear of the sucker rod, resulting in Check the pump frequently

Coupled with the inability of rod well pumps to play a role in deep wells, rod well pumps in the field of oil production are facing serious challenges

Rodless oil production pumps, such as electric submersible pumps and jet pumps, have their own inherent defects that cannot be eliminated, making it difficult to play a leading role in oil production in inclined wells

[0003] Originally, the hydraulic oil well pump that realizes reversing in the well is the best technical route for the development of rodless oil well pumps. However, the design scheme of the hydraulic piston pump imported from the United States in the 1980s has serious deficiencies, and the flow resistance of the pipeline in the pump is as high as 3.8-5.3 Mpa, which is equivalent to the back-and-forth flow resistance in the liquid pipe when the depth of the lower pump is 2000-3000m; in addition, the reversing valve and the control mechanism move synchronously with the power cylinder. The fatal flaw of this control method is: no matter how low the movement speed of the power cylinder is, No matter how wear-resistant and corrosion-resistant the dynamic seal of the reversing valve is, the short dynamic sealing surface is difficult to achieve the working life of several months of continuous operation.

Although this rodless hydraulic oil pump has its advantages, its disadvantages are also obvious: 1. It can only be controlled by a single well, which is inconvenient to manage; 2. The configuration equipment is complicated and the operation is troublesome; High cost; 4. It is difficult to guarantee the reliability of hydraulic components in the field environment; 5. The downhole signal transmission lags behind, and the invalid stroke of the pump increases. Therefore, the use prospect of this rodless hydraulic oil well pump is still not optimistic.

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