SU1694903A1 - Method of material extraction from thick underground formations through holes - Google Patents

Abstract

The invention relates to geotechnology and m. used in downhole hydraulic mining of mineral resources in permafrost conditions. The purpose of the invention is to increase the efficiency of work on the extraction of materials from subterranean formations by simplifying the process of forming the beneficiary layers and expanding the conditions for its use. For this, the formation is opened with a borehole and the rocks are eroded by intervals, leaving the pillars. The entire volume of the exhausted space is filled with water. At even intervals with a countdown from the roof of the formation, pieces of the finished plastic with closed porosity are supplied in a volume sufficient to form a compliant layer. The supply of plastic into the worked-out space is carried out through becoming a water-jet assembly, starting from the top, and after forming the pliable layers, becoming the water monitor is cooled to t-ry, less t-ry freezing water. The well is preserved until the water freezes, after which it is restored, the rocks of the pillars are washed out and the rock mass is raised to the surface. The power of the eroded intervals is determined experimentally, based on the need to erode undiluted rocks of minimal height. 2 Il. Yo

Description

The invention relates to geotechnology and can be used in downhole hydraulic mining of minerals in permafrost conditions.

The purpose of the invention is to increase the efficiency of work on the extraction of materials from underground formations by simplifying the process of forming compliant layers and expanding the conditions for its use.

Figure 1 shows a scheme for filling intervals with water and a filler; figure 2 - scouring the breeds of the pillar.

The method is carried out as follows.

Initially, the formation to the lower boundary of the extraction is opened by the borehole 1, in which the downhole jetting unit 2 is placed. With this unit a circular erosion of rocks along the height of the formation is performed, leaving the pillars 3 between the intervals. Odd intervals 4 (counting from the roof of the formation) are conducted with a radius greater than the radius from the excavation chamber, and even intervals 5 are washed out with the radius of the chamber.

It is preferable to blur the intervals from the upper extraction limit to the lower one. The power of the specified intervals 4 and 5 NUCLEON SE

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about

with

less power than the remaining 3 points between the intervals.

After washing out all the intervals within the limits of the extraction, water is pumped into the well 1, filling it with all the developed space,

In well 1, it remains to become a hydromonitor 2, through which the developed space of intervals 5 is filled with easily deformable material with -closed porosity (for example, plastic, whose pores are isolated from each other). At the same time, ready-made plastic is used for filling, which is formed in advance, in an amount sufficient to fill the worked-out space at appropriate intervals (if there are large stocks of light slag such as coal waste, these materials can be used as a placeholder).

The preparation of the filler is reduced to the separation of the material into pieces, the dimensions of which exclude the possibility of their getting stuck in the water monitor (i.e., the largest size of the piece must be no more than 1/3 of the internal diameter of the rod).

Before the start of work on the formation of compliant layers, becoming a hydromonitor 2 is supplied with cuffs of elastic material that are fixed along the length of the rod, eliminating the possibility of the filler exiting (floating up) through the gap between the hydromonitor 2 and the walls of the well 1 (when the specified gap is smaller than the piece size padding, cuffs will not be needed).

The filling of the developed space of the intervals 5 is conducted from top to bottom, while becoming a hydromonitor 2 is lowered into the well 1 until the lower cuff of the stand itself overlaps the area of the well 1 located above the interval 5 to be filled, then feed the aggregate to fill the developed space interval 5 and sections of well 1, directly adjacent to this interval.

Thereafter, in the same order, the next lower interval of 5 n, etc., is filled in. Until all intervals 5 to be filled are filled.

In the process of filling intervals 5, the volume of water contained in these intervals will be reduced to a minimum due to the displacement of water by the aggregate (plastic).

After that, the work area is preserved until the water is completely frozen in odd intervals 4, with

This is simultaneously carried out by cooling the jetting unit 2, for example, by supplying cold coolant to it or by cooling the protruding from the well.

plot stavom 2-. First of all, water freezes in areas of the well that cross the pillars, because the intensity of cooling (heat removal) within these volumes of water is maximum,

0 since the ratio of the area of the cooling surface to the amount of water in these areas of the wells is greater than in the areas crossing the developed space of the intervals.

5 Thus, before the water freezes in the intervals 4, ice is formed on the plug, isolating the intervals 5 from the intervals 4, eliminating further the connection of these intervals in the process of freezing water.

0 On the freezing of water can be judged on the basis of preliminary experiments.

By virtue of increasing the volume of the filler (ice) of odd intervals 4 and due to

5 the presence of a significant number of pores filled with gas in the volume of the filler (plastic), which filled the developed space of even intervals 5, when water freezes, there is a sharp

0 redistribution of load on the pillars 3 and softening of their rocks. In each case, on the basis of the experiments, the power of odd and even intervals, as well as pillars, is determined to ensure 5 the most uniform softening of the rocks of pillars 3, while starting from the minimum possible height of the intervals 4 and 5, the rocks of which need to be washed out in an unordered state. air jet unit 2.

The volume of the aggregate in the range of 5 takes more than the volume required to trigger the ice (formed in the range of 4) by an amount that provides

5 to compensate for the decrease in the volume of the aggregate due to the formation of ice in the volume of water remaining in the interval 5 after filling it with pieces of plastic.

Following the weakening of the pillars, the well is restored by defrosting the hydraulic monitor 2 and eroding the weakened pillars 3 and the deformed compliant layers 6 between the ice bridges 7 formed in odd

5 intervals.

Due to the fact that the ice bridges extend beyond the contours of the excavation chamber, they serve as supporting pillars that preserve the walls of the chamber in a stable state at its high altitude. In addition, the said ice bars 7 protect the cleaning space in which the jet monitor operates from possible sudden dumps from above. To reduce the effect of thaw on the solidity of the bars 7, the mining of rocks and the deformed compliant layer between adjacent bridges are performed in sequence from top to bottom. This allows you to save the underlying jumper, under which will produce further testing in a monolithic state.

Claims (1)

The method of the borehole extraction of materials from thick underground formations, including the opening of the formation with a well, interval formation along the height of the formation, leaving the pillars between intervals, filling the developed space of part of the intervals with water forming in the developed space the remaining intervals of compliant layers of easily deformable material closed porosity, the preservation of the well before the water freezes, the subsequent restoration of the well, the erosion of the rocks of the pillars and the rise of the rock mass to the surface, characterized in that, in order to increase the efficiency of work on extracting materials by simplifying the process of forming pliable layers and expanding the conditions for its use, with water, the entire volume of the developed space of the formation, after which pieces of the finished plastic are fed into the developed space of intervals intended for the formation of a compliant layer. Scales with closed porosity in a volume sufficient to form a compliant layer, while supplying plastics into the developed space of the corresponding intervals lead through becoming a water-jet assembly sequentially, starting from the top, and after forming the pliable layers, the water-jet is cooled to a temperature lower than the freezing temperature of water.