Oil and water well production string and production method thereof covered with hot-melt plastic layer inside and outside

Abstract

The invention discloses an oil and water well extraction and injection tubular column internally and externally wrapped with hot melting plastic layers and a manufacturing method of the tubular column. The inner wall and the outer wall of each extraction and injection steel pipe are wrapped with the hot melting plastic layers, and the extraction and injection steel pipes are in screw connection with each other through pipe couplings. As for a pipe opening gasket between pipe openings of every two extraction and injection steel pipes, an inner ring is in a slab shape, the outer ring is in a trapezoid with the larger outside and the smaller inside, and the trapezoidal outer ring of the pipe opening gasket is firmly embedded into a trapezoidal groove of the corresponding pipe coupling. The inner wall and the outer wall of the overall tubular column are both wrapped with plastic, no gas and no steel exposed point exist between the inner walls of the extraction and injection steel pipes and the hot melting plastic layers, and the condition that liquid and gas make contact with steel is obstructed. Owing to the fact that inner layer plastic and the outer layer plastic cannot fall off, the effect that the tubular column inner walls of full oil extraction wells and injection wells are completely resistant to corrosion is achieved, and the wear-resistant effect of the tubular column pipe walls is achieved, so that the service life of the overall extraction and injection tubular column is prolonged by 3-5 times, and the repairing-free periods of the oil and water wells are prolonged by 2-3 times. According to the extraction and injection tubular column, steel is saved, the oil exploiting cost is reduced, the failure rate of the oil wells is decreased, and working efficiency is improved.

Description

technical field [0001] The invention is used for oil production and water injection pipe strings used in oil fields, oil production wells, directional oil production wells, horizontal oil production wells, rod and pipe eccentric wear production wells, water injection wells, etc., especially an oil and water well covered with a hot-melt plastic layer inside and outside Production injection string and its manufacturing method. Background technique [0002] At present, most of my country's oil fields have entered the middle and late stages, that is, the period of secondary and tertiary oil exploitation. Oil wells have high water cuts and oil production declines. In order to further enhance the recovery factor, methods such as pumping chemical oil-increasing liquid agent, chemical well flushing, and three-component compound system flooding were adopted to improve the recovery factor. However, with the application of enhanced oil recovery technology, the scaling and corrosion o...

AI Technical Summary

Problems solved by technology

However, there are many problems in this composite tubing string, mainly as follows: 1. Because there is a gap of 8-10mm at the joint of the two tubing couplings, it will cause the concentration of corrosion points, aggravate the corrosion, and make the tubing unable to fully The purpose of anti-corrosion

2. The anti-corrosion of the inner wall of the oil pipe is to embed the anti-corrosion liner in the inner hole of the oil pipe. The inner wall of the oil pipe and the inner liner are not completely integrated. During long-term use, it is easy to move in series under the influence of the temperature of the oil well. Expansion and bulging, resulting in corroded space between the lining pipe and the oil pipe, and ring fouling

3. There are no anti-corrosion measures on the nozzle cut of the oil pipe, forming a corrosion-prone area

4. The thickness of the outer coating of the oil pipe is 0.6-0.8mm, which is not wear-resistant, and the coating is easy to peel off during long-term use

[0004] In view of the lack of anti-corrosion measures for the nozzle of the oil pipe, someone proposed a new design scheme, which is to place a gasket between the nozzles of the two-phase oil pipe. , but its defect is that after the oil pipe is used for a long time, due to the continuous impact of the oil and water in the pipe on the gasket, the gasket may be deformed and washed off into the oil pipe

In this case, not only does it have no anti-corrosion effect on the nozzle, but also directly affects the firmness of the pipe string due to the gap between the two nozzles.

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