SU857449A1 - Method of underground dissolution of salt formations - Google Patents

Description

(54) METHOD OF UNDERGROUND DISSOLUTION OF SALT FORMATIONS

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The invention relates to mining and can be used in the extraction of rock and other soluble salts, as well as in the construction of underground storage tanks in salt formations.

There is a known method of underground dissolution of salt formations through boreholes, which includes erosion of the walls of the subterranean chamber by pumping solvent through a well, passed through a magnetic field 1.

The disadvantage of this method is the insufficient dissolution rate and the difficulty of controlling the shaping of the underground chamber.

There is also known a method of underground dissolution of salt formations through boreholes, including washing the walls of the subterranean chamber by pumping salt and nonsolvent through the well and pumping out the resulting brine to the surface 2.

The disadvantage of this method is the low rate of the salt dissolution process.

The purpose of the invention is to intensify the salt dissolution process.

The goal is achieved by passing the non-solvent before injection through a magnetic field and treating the walls of the underground chamber with a specified e-solvent before washing them.

Moreover, the non-solvent is passed through a magnetic field of 3500-4000 Gs.

In this case, the walls of the underground chamber are processed by creating a layer of non-solvent in the lower part of the said chamber and gradually raising the latter to the roof of the chamber on a brine pad.

In addition, the processing of the walls of the underground chamber are jet non-solvent.

In addition, the walls of the underground chamber are processed by filling the said 5 chamber with a non-solvent.

FIG. 1 shows a plot of the speed of the NPR of the penetration of a non-solvent of diesel fuel into the rock salt depth against the depth h of its penetration into the salt; in fig. 2 - graphs of the brine concentration (s) versus the velocity (Vp) of the erosion of the chamber walls (1 - using solvent (water) and non-solvent (diesel fuel) untreated by a magnetic field; 2 - using solvent (water) treated with a magnetic field and non-solvent (diesel fuel), untreated by a magnetic field; 3 - the use of solvent (water), non-processing. A magnetic field, and non-solvent (diesel fuel), treated with a magnetic field).

The method is carried out as follows.

The salt formation is opened by the well and pumped into it is a solvent, such as water and a non-solvent, such as diesel fuel, which serves to control the shaping of the underground chamber.

A non-solvent passed through a force magnetic field, for example, 3500-4000 Gs, is pumped into the formed chamber and treated with the non-solvent walls of the underground chamber, after which the solvent is introduced into the chamber, which blurs the walls of the chamber with formation of brine pumped out through the well to the surface . The treatment of the walls of the underground chamber with a non-solvent can be carried out by forming a layer of non-solvent in the lower part of the chamber and gradually raising the latter to the roof of the chamber on a brine pad formed during the subsequent injection of the solvent into the chamber.

This treatment can also be conducted by a jet of a non-solvent or by filling the chamber with a non-solvent.

With the passage of a non-solvent, such as diesel fuel, through a force magnetic field of up to 4000 Gs, their rheological properties change and their penetration through the microcracks into the salt layer is enhanced when in contact with it. Having a wedging effect on microcracks and penetration into the salt layer, the non-solvent treated with a magnetic field increases the size and extent of salt outcrop in the cracks, i.e. increases the area of the dissolving surface without increasing the size of the leaching chamber.

After treating the chamber walls with a non-solvent treated with a magnetic field, the solvent, gaining access to them, penetrates into a network of cracks formed by the proppanting effect of magnetised liquid hydrocarbons. Due to the increase in the contact surface area of the salt-solvent, the concentration of the brine in the leaching chamber increases and its average horizontal scour velocity. After dissolving the layer from the side walls of the leaching chamber to the depth of penetration

cracks formed by a non-solvent treated with a magnetic field, the walls of the chamber are again treated with one of the methods described above.

The use of this method allows to reduce the time of erosion of cameras, reduce

capital costs for the preparatory erosion of the underground chamber, increase the concentration of brine during the erosion of the chambers, improve the performance of the scour chambers and reduce capital costs for the construction of storage facilities for weak brines.

Claims (5)

1. A method of underground dissolving salt formations through boreholes, including washing the walls of an underground chamber by pumping a solvent of a salt and a non-solvent through a well and pumping out the resulting brine to the surface, which in order to intensify the salt dissolution process, a non-solvent is passed through magnetic saw and process the wall of the underground chamber with a specified non-solvent before they are washed out. 0 2. A method according to claim 1, characterized in that the non-solvent is passed through a magnetic field of 3500-4000 G. 3. The method according to paragraphs. 1 and 2, characterized in that the processing of the walls of the underground chamber is carried out by creating in the lower part 5 specified chamber layer of non-solvent and the gradual rise of the latter to the roof of the chamber on the brine pad. 4. The method according to paragraphs. 1 and 2, characterized in that the treatment of the walls of the underground chamber is conducted by a jet of a non-solvent. ° 5. The method according to paragraphs. 1 and 2, characterized in that the treatment of the walls of the underground chamber is carried out by filling said chamber with a non-solvent. Information sources, 5 taken into account during the examination 1. USSR author's certificate number 196011, cl. E 21 B 43/28, 1965. 2. USSR author's certificate number 77733, cl. E 21 B 43/28, 1949.