A large-displacement continuous downhole sand cleaning and plugging removal pipe string and sand cleaning and plugging removal technology

Abstract

The invention discloses a large-displacement continuous downhole sand and plug removing tubular column and a sand and plug removing process thereof. The tubular column comprises a pump cylinder, wherein a hollow plunger and a plunger connecting rod are arranged in the pump cylinder, the plunger can slide up and down relative to the pump cylinder, a traveling valve is connected to the upper end of the plunger connecting rod, the upper end of the traveling valve is connected with an on-pump oil tube in a sealing mode, the lower end of the pump cylinder is connected with a sand smasher, and a bottom valve is arranged in the upper end of the sand smasher. In the sand removing process, clear water of a certain volume is injected into the on-pump oil tube from a wellhead, and a valve ball of the traveling valve is connected with a valve port in a sealing and matching mode; the on-pump oil tube is lifted up and dropped down continuously to drive the plunger to move up and down ceaselessly, and sand carrying well liquid is discharged back to the wellhead through the on-pump oil tube after being pumped into the pump cylinder. According to the tubular column, the upper portion of the traveling valve is closed, sand accumulating in a shaft can be thoroughly removed simply through continuous operation of the technological tubular column next time, and the sand removing efficiency is greatly improved.

Description

technical field [0001] The invention relates to the technical field of mechanical sand removal in oil production well shafts in the petroleum industry, in particular to a large-displacement continuous downhole sand removal and plug removal pipe string and a sand removal and plug removal process. Background technique [0002] Sand production in oil wells is one of the main problems faced in the exploitation of sandstone reservoirs at home and abroad, which seriously affects and restricts the normal production of crude oil and the improvement of economic benefits. Especially for oilfields that are in the middle and late stage of production, affected by unfavorable factors such as high water cut in oil wells, large pressure drop in formations, high-intensity single-well liquid extraction and unbalanced injection-production in production intervals, formation deficits and serious negative pressures , Oil wells are generally seriously sanded. [0003] Sand dredging pump negative ...

AI Technical Summary

Problems solved by technology

However, a small number of sand storage pipes can only deposit and hold a small amount of sand, and cannot remove the thick sand column in the wellbore at one time. It is necessary to lift and lower the sand fishing string many times, and experience repeated sand fishing, which prolongs the operation time. It takes one to two days to achieve the purpose of completely removing the sedimentary sand in the wellbore, resulting in low sand removal efficiency

Especially with the continuous increase of rolling development and depth tapping, there are more and more deep wells and low-energy oil production wells with deep dynamic fluid surface put into development in various oil fields. When these wells use traditional sand fishing technology to clean wells The problems of low sand removal efficiency, incomplete sand removal, and even failure of sand removal are more prominent

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