EA009429B1 - Method of working out low-thicked salt deposit beds by underground leaching - Google Patents

Abstract

The invention relates to geotechnology and can be used in leaching of minerals out of ore bodies.The invention is aimed at enhancing effectiveness of using low-thicked potassium beds.The low-thicked potassium beds are drilled by a plurality of injection and production wells. Joining of the injection and production wells as well as forming of “lying” leaching chambers between wells in the low-thicked potassium beds for excluding development of filtration canals when forming the leaching chambers in undesirable direction, in particular, in underlying and overlying beds is realized by drilling horizontal shafts in production beds by using coiled tubing installations and flexible seamless extremeline pipe.Thus, the inventive method provides enhancement of salt beds development by underground leaching.

Description

The invention relates to the field of geotechnology and can be used in the leaching of minerals from ore bodies.

It is known that the extraction of solid minerals by the leaching method is a new promising method for the discovery of salt deposits and their development. The industrial development of such methods for the extraction of solid minerals is based on technical, economic and socio-ecological indicators of production. The progressiveness of new technologies can significantly reduce the harmful effects on the environment compared to traditional technologies. Thus, the extraction of solid minerals through wells can significantly reduce industrial waste, eliminate time-consuming operations to fill depleted areas, and reduce the time factor for land reclamation for subsequent rational use. Such operations as transportation and crushing of ores, blasting, storage of rocks and tailings of technological ore processing are also excluded.

A known method of salt extraction by underground leaching, in which the reservoir of salt is opened by a well, into which casing, water supply and brine-lifting columns are installed. Due to the supply of the solvent in the water supply column and the rise of the resulting brine along the brine-lifting pipe, the preparatory development and the formation of the reservoir within the chamber (1) are washed out.

The disadvantage of this method is its low efficiency in the development of reservoir deposits of minerals of low power.

There is a method of joining wells in underground leaching of salts, including drilling and hydraulic fracturing of the salt reservoir (2) - a prototype.

The disadvantage of this method is that the coupling of injection and production wells or leaching chambers using even directional hydraulic fractures leads to the development of fracturing in productive strata in arbitrary directions. This does not exclude the possibility of the formation of undesirable fracturing in the overlapping and underlying rocks, which can become filtration channels on the one hand to break through the ground and stratum waters into the zone of mining, and on the other hand - migration routes for the departure of working agents. These processes dramatically reduce production efficiency.

The objective of the invention is to increase the efficiency of mining potash seams of low power.

The task is achieved by the fact that in the method of salt extraction by underground leaching, including the opening of the reservoir wells, killing wells, the formation of leaching chambers, the solvent injected into the injection wells and removing the resulting brine from pumping wells, killing wells and forming leaching chambers carry out a network of horizontal wells in drilling them using coiled tubing rigs and flexible seamless pipes.

FIG. 1 shows the layout of production and injection wells; FIG. 2 shows section A-A in FIG. one

The way to develop layers of potassium salts of low power as follows.

Potassium reservoirs 1 of low power reveal a network of injected 2 and production (pumping) 3 wells. Injection 2 and production 3 wells, as well as the formation of “lying” leaching chambers 4 between the wells in low-thickness potash reservoirs 1, to prevent the development of filtration channels in an undesirable direction, in particular, in the underlying 8 and overlapping 9 rocks, driving horizontal shafts 5 in salt formations by drilling them using coiled tubing units 6 and a flexible seamless coupling pipe 7. The brine obtained in the leaching chambers is pumped out of the mining well John 3 and fed to a recycling.

Thus, the proposed method of development allows to increase the efficiency of development of layers of salt deposits by underground leaching by ensuring reliable pumping of injection and pumping wells;

eliminate the possibility of the development of filtration channels in undesirable directions and, in particular, in the underlying and overlapping rocks.

Claims (1)

CLAIM A method of developing low-salt salt reservoirs by underground leaching, including opening a productive formation with a network of injection and production wells, supplying solvent and pumping out brine, shutting down wells and forming a leaching chamber, characterized in that the shutting down of wells and formation of leaching chambers is carried out using a network of horizontal shafts by their drilling using coiled tubing rigs and a flexible seamless pipe.