Salvage type air-tap-adjustable downhole throttling device based on magneto-rheological elastic rubber

Abstract

The invention discloses a salvage type air-tap-adjustable downhole throttling device based on magneto-rheological elastic rubber. The adjustable downhole throttling device comprises a putting head, wherein the putting head is connected with a positioning ring, the inner ring of the positioning ring is connected with an oil pipe, the oil pipe penetrates through a fishing neck, a slip, a conical seat and a magneto-rheological elastic rubber sealing rubber cylinder, and the end head is provided with an air tap; a spring and a small ball which can move up and down are arranged in the air tap, andthe small ball can adjust the flow quantity of fluid flowing through the air tap; the magneto-rheological elastic rubber sealing rubber cylinder is divided into three layers, namely a manganese-zinc permanent magnet, magneto-current elastic rubber and oil-resistant rubber from inside to outside, and the manganese-zinc permanent magnet and the magneto-current elastic rubber are attracted with eachother; during setting, the rubber cylinder is shaped outside a well, and then is put into the well, the slip anchors an annular pipe, and under the oil-gas axial compression expansion acting force, the rubber cylinder and the oil pipe are sealed; and during unsetting and salvaging, the rubber cylinder is put into a high-temperature heat conductor, the magnetism of the manganese-zinc permanent magnet disappears, the magneto-current elastic rubber is changed into a rubber body capable of deforming from a solid, and the rubber cylinder and the oil pipe can be unset and salvaged. The salvage typeair-tap-adjustable downhole throttling device has the advantages of being simple in structure, time-saving and labor-saving, high in efficiency and good in safety.

Description

technical field [0001] The invention relates to a downhole choke, in particular to a salvageable downhole choke with an adjustable gas nozzle based on magneto-rheological elastic rubber. Background technique [0002] The downhole choke is an important downhole tool to achieve throttling and pressure reduction, production control, control of hydrate formation, and simplification of surface processes in the production process of gas wells, especially high-pressure gas wells. The clamping mechanism of the tubing slip type downhole choke currently used is composed of three slips with the same tooth shape, material, and processing technology, and is fixed by the force generated by the slips and the inner wall of the tubing relying on the pressure difference. However, as the diameter of the gas well production string increases, the sealing area of ​​the slip-type downhole choke increases, and the pressure difference it bears after setting also increases. Relative displacement occ...

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Problems solved by technology

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to provide an adjustable downhole choke with a salvageable gas nozzle based on magneto-rheological elastic rubber, which can automatically adjust the size of the choke nozzle in time according to the operation situation. Avoid the instability of the collection volume caused by the change of the downhole environment to meet the needs of centralized transportation; at the same time, it solves the problem of creep and aging under the action of high temperature, high pressure and fatigue alternating loads when the rubber tube is sealed with the tubing, and the adhesion with the tubing As a whole, it is difficult to salvage the restrictor. It has the advantages of simple structure, saving time and effort, high efficiency and good safety.

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