Air cushion type brine mining method for salt rock stratum containing high-impurity salt rock and mudstone interlayer

Abstract

The invention discloses an air cushion type brine mining method for a salt rock stratum containing a high-impurity salt rock and a mudstone interlayer. The air cushion type brine mining method comprises the following steps that (1), a dissolving cavity is formed; (2), high-pressure gas is injected through a gas injection channel between a cavity making outer pipe and a brine central pipe, and an air cushion is formed at the top of the cavity; (3), lateral dissolving is carried out, and after the transverse size of the cavity reaches the standard, and the gas-liquid interface is kept above a salt rock roof; (4), when upward dissolving is carried out for a period of time and corrosion is insufficient, the displacement of injected clear water is increased; (5), when the mudstone interlayer ismet during upward dissolving, the gas-liquid interface descends to form an air cushion below the mudstone interlayer, and after the transverse size of a cavity below the mudstone interlayer reaches the standard, the gas-liquid interface is lifted to enable the brine to make full contact with the mudstone interlayer so as to promote the brine to permeate, soften and collapse the mudstone interlayer; and (6), after the mudstone interlayer is completely collapsed, the cavity is mainly dissolved upwards, and step 3-6 are repeated. The problems of corrosion of the high-impurity salt rock stratum,interlayer collapse control and cavity form control are solved.

Description

technical field [0001] The invention relates to a method for extracting brine, in particular to an air cushion method for extracting brine. Background technique [0002] my country is a big country for mine salt mining. The annual amount of well mine salt mining reaches 50 million tons, which is close to 60% of my country's salt production. A large amount of industrial raw material - NaCl can be obtained through well mine salt mining. At the same time, huge dissolved cavities can be formed underground through the mining of mine salt, and these cavities are recognized as ideal spaces for oil and gas reserves at home and abroad. my country's dependence on foreign oil and natural gas is as high as 70% and 45%, and establishing a complete strategic oil and gas reserve system is an important part of ensuring national energy security. In particular, the escalation of the Sino-US trade war and the raging new crown epidemic remind us of the urgency of building our own energy storag...

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Problems solved by technology

[0005] The purpose of the present invention is to provide an air-cushion brine mining method for salt rock formations containing high-impurity salt rock and mudstone interlayers, to solve the problems of dissolution of high-impurity salt rock formations, control of interlayer collapse and cavity shape control, and at the same time solve The problem of how to obtain high-value refined brine in brine mining and cavity construction in salt mines

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