RU2239057C1 - Method for underground extraction of hydro-mineral resources - Google Patents

Abstract

FIELD: geology.

SUBSTANCE: method includes drilling horizontal well along salt bed, then lowering brine-raising and water-supplying concentric pipe columns into well. Solvent is fed to ring space, exit from which is placed at beginning of horizontal portion, and forming brine gets into inner pipes column, end of which is placed near pit-face of horizontal well. Wash-out of formed horizontal tunnel is continued until transverse dimensions of tunnel are enough for guaranteed opening of it by vertical wells. Drilling of vertical wells is performed until crossing tunnel hollow.

EFFECT: higher speed of operation, no need for hydro-destruction of bed.

2 dwg

Description

The invention relates to geotechnology and can be used for downhole extraction of hydromineral raw materials from salt deposits, as well as to create underground gas storages (UGS) in salt formations.

A known method of leaching minerals from productive formations of low power, including opening a productive formation with a vertical well, forming a fan of radial horizontal channels from a given well, within the productive formation and leaching of the productive formation through a mud column and flexible pressure hoses located in horizontal channels [1].

The disadvantage of this method is its low productivity.

A known method of mining salt formations by underground dissolution, including drilling a horizontal well along a salt formation, drilling a vertical well before connecting it to the bottom of a horizontal well, leaching a salt formation through a horizontal well, drilling vertical wells in two parallel rows on either side of a horizontal well, connecting them at hydraulic fracturing and pumping brine both from the main production vertical well and from other vertical wells, successively injected commissioned in the direction from the horizontal well to the main production well [2].

The disadvantages of this method are the need to use fracturing operations to intensify the leaching process, as well as its lack of productivity.

The purpose of the invention is the elimination of the above disadvantages. This goal is achieved by preliminarily washing the horizontal well until the transverse dimensions of the resulting tunnel capacity are sufficient for guaranteed opening of the tunnel by vertical wells, while drilling vertical wells is carried out before crossing the tunnel capacity.

The proposed method is implemented as follows. Initially, a vertical section of horizontal well 1 is drilled (Fig. 1) to the roof of saline deposits, then the well is cased with column 2 and cemented. A horizontal section of well 1 is drilled from beneath the shoe of the casing string 2 along the salt formation close to its bottom, then brine-raising 3 and water supply 4 pipe strings are arranged in a concentric position. The solvent (water) is fed into the annular space, the exit from which is located at the beginning of the horizontal section, and the resulting brine enters the pipe string 3, the end of which is located near the bottom of the horizontal well 1. The well above the horizontal section is filled with liquid - non-solvent 5 to prevent erosion of the inclined plot. The brine lifting column 3 is equipped with centering lights 6 in order to uniformly erode the walls of the horizontal section of the well. The erosion of the resulting horizontal tunnel is continued until the transverse dimensions of the tunnel are sufficient for its guaranteed opening by two vertical wells 7 and 8 (figure 2). After lowering the casing strings to the roof of the salt formation and cementing them, the boreholes 7 and 8 are drilled to the intersection with the tunnel capacity, after which the boreholes 9 are lowered into the boreholes 7 and 8, followed by sealing the annulus with packing devices 10. From the borehole 1, pipe columns 3 and 4 are lifted seal it and continue washing out the tunnel capacity, pumping solvent into well 8 and obtaining brine in well 7. Due to the fact that the diameters of the columns 9 are larger than the diameter of the brine lifting column 3 in a horizontal well, the process erosion tunnel capacity significantly intensified. The formation of insoluble sediment 11 at the bottom of the tunnel tank slows down the erosion of the lower wall of the tunnel, therefore, the growth of the tank occurs towards the roof of the salt reservoir. For a more uniform increase in the diameter of the tunnel, the functions of vertical wells 7 and 8 are alternately changed from injection to production and vice versa. The tunnel erosion process is continued until the ceiling of the tunnel reaches the roof of the salt layer.

Sources of information

1. The method of leaching of minerals from reservoirs. A.S. 1525269 USSR, MKI E 21В 43/28 / Smirnov M.M., Yuroyts A.V. and etc.

2. The method of mining salt formations by underground dissolution: A.S. 720142 USSR, MKI E 21 V 43/28 / Odnopozov V.L. (prototype).

Claims (1)

A method of underground production of hydromineral raw materials, including drilling horizontal and vertical wells, injecting solvent into one vertical well and pumping brine into another, characterized in that the horizontal well is preliminarily washed until the transverse dimensions of the resulting tunnel capacity are sufficient to guaranteed opening of the tunnel by vertical wells, while drilling vertical wells is carried out before intersecting with the tunnel capacity.

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