SU1086133A1 - Method of mining salt deposits - Google Patents

Abstract

A METHOD FOR DEVELOPING SALT FILES, including supplying an aqueous solvent and non-solvent - oil products to boreholes, washing the preparatory chamber - hydraulic pipe to form a layer impregnated with oil products in the roof of the chamber, releasing the non-solvent from the chamber and working the bottom-up reservoir to get a brine layer, different brine, different saline. that, in order to increase the development efficiency by increasing the rate of salt dissolution in the roof of the chamber, after the release of the non-solvent, the roof is treated with a solvent with acidity of pH 8-9 i to dissolve the layer impregnated (A petroleum.

Description

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The invention relates to a technique for the extraction of fossil salts by underground dissolution in the subsoil, mainly to the mining and chemical industry, and can be used in other areas that produce brine production through boreholes. There is a method of developing salt deposits through boreholes by supplying them with aqueous solvent, petroleum products used as nonsolvent, washing out the preparatory chamber - hydraulic pipe and working out (dissolving) the bottom-up deposit after releasing the nonsolvent cell C11. The disadvantage of this method is that within 8-10 months after the release of non-solvent - oil products from the chamber and the creation of conditions in it for intensive dissolution of salt in the roof of the chamber, during which industrial brine is formed, the brine formation (well productivity) is it is 50-60% of the value that should be provided when the prepared area of rock salt is dissolved in the roof of the chamber and the known rate of its dissolution with water is 19-24 So during the first 8-10 months of operation chambers (wells) with diameters of 90-100 m, the brine production of each one is actually 20-25, while the prepared horizontal area of the rock salt surface in the roofs of the chambers can provide 40-50 capacity, which is achieved through 10-12 months after the injection of non-solvent - oil products from the preparatory chamber - hydrovrub (start of operation). The reason for the low actual productivity of the chamber brine formation compared to the potential capacity of the chamber having a certain roof area is the presence of a layer of rock salt in the roof, which is impregnated with non-solvent oil products, which penetrate it through microcracks during a long contact of oil products with the roof under pressure. The calculated thickness of this layer, determined by the actual maximum well productivity during the first 8-10 months of its operation after the launch of oil products from the preparation chamber with a diameter of 90-100 m, is 2-3 m. The dissolution rate of the horizontal surface of the rock salt in the roof of the chamber, impregnated with petroleum products, has a value of 1.5-2 times lower than the rate of dissolution of pure fossil rock salt. The closest to the proposed technical essence and the achieved result is the method of developing salt deposits, which includes supplying an aqueous solvent and a non-solvent — oil products — into wells, scouring a preparatory chamber — a hydraulic pipe — to form an oil-saturated layer in the roof of the chamber, releasing the non-solvent and working out the bottom-ups with the production of industrial brine C 2. The disadvantage of this method is the low productivity of the development due to the slow dissolving chamber roof after the release of oil due to contamination of its last. The purpose of the invention is to increase the development efficiency by increasing the dissolution rate in the roof of the chamber. The goal is achieved by the fact that according to the method of developing salt deposits, which include supplying an aqueous solvent and non-solvent oil products to boreholes, washing the preparatory chamber of the hydraulic tube to form an oil-impregnated layer in the roof of the chamber, releasing the non-solvent from the chamber and working the deposit upwards to produce industrial brine, after the release of non-solvent, the roof is treated with a solvent with a pH of 8-9 to dissolve the oil-impregnated layer. The essence of the proposed method is as follows. After scouring the preparatory chamber - hydrovrub using oil as a non-solvent, they are released from the chamber to the surface along the wellbore. For 8-10 months after this, to work out the lower layer of the roof of the chamber, 2-3 m thick, impregnated with oil products, an aqueous solvent with a pH value is fed into the chamber (well)

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 8-9, which dissolves salt in the roof of the chamber and, penetrating into it through microcracks filled with oil products, transfers them to soluble compounds discharged in the brine medium from the roof of the chamber downwards. Thus, simultaneously with the dissolution of the roof with an aqueous solvent with a pH of 8-9, the surface of the layer and the volume of the layer impregnated with oil products are cleaned of residual oil products. At the same time, the average dissolution rate of the roof of the chamber — the horizontal surface of rock salt impregnated with oil products — is increased by 1.5-2 times, reaching the dissolution rate of pure fossil salt and ensuring, immediately after discharging the nonsolvent from the chamber, the well production rate of the brine, which is obtained using a conventional method 10-12 months after the transfer of the well to the operating mode. The adjustment of the pH of the solvent is made by adding aqueous solutions of alkalis to it, the content of which is not limited by the technical conditions for crude brine: NaOH, Na2C02 are used for chloric acid, and soda and solvaconic liquor are used.

Conducted laboratory studies have shown that the weighted rate of dissolution of the horizontal surface of rock salt, neob334

botanical oil products (diesel fuel), practically does not depend on the pH of the solvent. The rate of dissolution of the horizontal surface of rock salt, which has been for a long time (up to 8-10 months) in diesel fuel (under pressure up to 18 Sha), is a solvent with 1.5-2 times lower than the rate of dissolution by water (or the same solvent) of the horizontal surface of the stone salt that is not in contact with diesel fuel. When the pH of the solvent is greater than 8, the rate of dissolution of the horizontal surface of rock salt impregnated with diesel fuel is almost equal to the dissolution rate of rock salt that has not been in contact with diesel fuel, i.e. increases by 1.5–2 times compared to the rate of its dissolution with water. Increasing the pH of the solvent to more than 9 practically without increasing the dissolution rate leads to an increased consumption of chemicals and unreasonable costs. Therefore, take the lower limit of the effective value of pH 8, the upper limit of its limit pH 9

The use of rock salt in the chamber of underground plant after the release of a non-solvent oil product with a pH value of 8–9 after it releases increases the rate of roof dissolution of the chamber and the productivity of the brine production from the well.

Claims (1)

METHOD FOR DEVELOPING SALT DEPOSITS, including supplying an aqueous solvent and a non-solvent - oil products to the boreholes, washing out the preparatory chamber - a hydraulic pipe with the formation of a layer saturated with oil products in the roof of the chamber, discharging the non-solvent from the chamber and working out the deposit from the bottom up to obtain an industrial brine, characterized in that , in order to increase the development efficiency by increasing the rate of dissolution of salt in the roof of the chamber, after the release of the non-solvent, the roof is treated with a solvent with acid pH 8–9 until the layer saturated with petroleum products dissolves. > 1 10861