SU1268745A1 - Method of degassing excavation fields in pillar mining - Google Patents

Abstract

The invention relates to the field of mining industry and is intended to reduce the gas abundance of mines (B) and increase the safety of mining work on the gas factor. The purpose of the invention is to increase the efficiency and cost-effectiveness of the method due to the possibility of using well depleted lava wells (C) for degassing the spent space (CW), which have degassed the previously developed reservoir. From mountain B 1 in the plane of reservoir 2 across the column, parallel C 3 is conducted. At the mouth, they are sealed (they are connected and connected to the degassing pipe 4 communicated with the vacuum system. At the end section 10 O) o 4

Description

the excavation floor from the flange B 5 drill C 6 along the column being worked out. Through the C 6 sections left in the pillars at the end of the work, the pulp is sucked out of the VP and its flow rate measured. On seams with low permeability C 3 bzF t from haulage and / or ventilation drifts with a turn on a clearing face. Along the table BAC 6 a drill of variable length and 68745

"They are drilled to the last C 3 at a distance equal to the distance between C 3. As the lava moves, C 3 and then C 6 are opened by the clearing face. To reduce air inflow into the conduit 4 when an aerodynamic coupling C occurs The bottomhole space of the operating lava vacuum at the mouth of the C is distributed in proportion to the gas flow rates. 2 hp f-ly, 4 ill.

The invention relates to the mining industry and can be used to reduce the gas abundance of mine workings and improve the safety of mining work on the gas factor. The purpose of the invention is to increase the efficiency and cost-effectiveness of the method of degassing due to the provision of the possibility of using the degassing of the worked out spent space: lava wells that have degassed a previously developed reservoir. Fig. 1 shows a schematic diagram of the degassing of excavation fields by wells; figure 2 is the same, the principle of excavation fields in layers with low gas permeability; fig.ZvTo same, extraction column, worked on the uprising of a long lava; Fig, 4 - the same, extraction column on the reservoir with a low gas permeability, worked on the uprising long lava. The method of degassing excavation fields is carried out as follows. From the mine workout 1 (Fig. 1), in the plane of the reservoir 2, wells 3 are led across the extraction column, which are cased with pipes (or sealers) at the mouth and connected to the degassing pipeline 4 communicated with the vacuum system of the mine (wing, block, section ). At the end of the excavation area from the flanking section 5 (fig., Wells 6 are conducted along the column being worked out, which, after isolation from the mine atmosphere, are connected to the degassing pipeline 7, wells 6 do not finish until the last well 3 for a distance equal to between wells 3. Establish the parameters of wells 3 (Fig. 1). The distance between wells 6 takes 1.5-2.5 times longer than the distance between wells 3, which is due to the high gas permeability of the coal array ahead of the lava in the area of technogenic cracks The well lengths 6 are determined by the capabilities of the drilling equipment. The wells 6, adjacent to the drift 1 and vent 8 drifts, are placed from the latter at a distance equal to the sum of the radii of drainage of the preparatory coal mining well and on the wells with low gas permeability 3 (Fig. 2) is held at an angle to the seabed line for 2-3 months before the lava approaches them. The distance between them is equal to one and a half or two times the distance between parallel-single wells. These wells are very productive in the area of technogenic fracturing ahead of the lava. The reversal angle of such wells is established by an experienced driver (it is approximately 50-70 approximately. In the sections of the reservoir worked by long lavas (more than 200 m), wells 3 are drawn from the haulage output 1, and wells 3 are from the ventilation well 8. 4 (FIGS. 3 and 4). In the case where the wells 3 are rotated on the working face, the wells 6 are drilled along the column of variable length and do not drill them to the last well 3 (FIG. 2) or

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wells 3 and 3 (FIG. 4) at a distance equal to the distance between parallel wells 3 and 3.

In the lavas working along the strike of the reservoir, the downhole wells 3 are held with a smaller interval than the upstream wells 3, since the rates of the downstream wells are usually 1.3-2.0 times lower. The well parameters are determined.

In the drop working lavas, wells 3 and 3 should be conducted with a rise relative to the dip of the formation at an angle of 1-3 °.

As the lava advances, first the wells 3 (Fig. 2) or the wells 3 and 3 (Fig. 4), and then the wells 6 (Figs. 1-4), are opened by a clearing face. In order to reduce air inflow, the vacuum at the mouths of wells with aerodynamic connection with the bottomhole space of the operating lava is distributed in proportion to the methane flow rates. The opening of the lava borehole is stubbed with coal that is beaten during the operation of the combine. With the bottomhole face, these wells communicate through a network of fractures. Therefore, their productivity is estimated by methane flow rate by known methods. At the same time, the vacuum on such wells is maintained, on the basis of ensuring the concentration of methane in the gas-air mixture being captured, at least 30% by volume. .

After stopping the lava, the wellhead 6 is covered so much that the gas entering the well from the remaining coal is reduced into the degassing system and there are no air leaks that reduce the methane concentration in the captured mixture. The boreholes 6, which by their side enter the bottomhole lava space, can be temporarily insulated from the side of the lava (e.g., portable sealers, plug-in plugs, etc.). After dismantling the equipment, by the time the isolation of the treated section of the formation is completed, the sealing device from the wells on the lava side is removed. Wells 9 (Figures 1–4) are used to suck the gas-air mixture from the above-found; waste space 10 (previously worked fields). The vacuum in the wells 9 is distributed in proportion to the flow rates of meth.

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The magnitude of the vacuum in wells with aerodynamic connection with the bottomhole space of the operating lava, as well as in wells drilled from flank workings, is controlled by methods known in mining practice. The main one is the method of reducing (or increasing) the channel cross section in the well casing by changing the position of the gate. Automatic or manual methods are possible for changing the position of the gate in the well casing or in the pipe that draws gas from the well to the local (or main) pipeline.

With the help of wells 9, drilled on the flank of the excavation column along the seam towards the lava with aimless

the technologies reduce the lava gas mobility in the adjacent excavation field, and sucked methane is sent for recycling. When guarding wells with the pillars, wells 9 additionally extract the meta: n, which makes it possible to eliminate the accumulation of methane in the developed space, reduce the gas content of the horizon and wing, and also produce associated gas for utilization. And in

this and in other cases, the additional extraction of methane contributes to improving the safety of mining operations.

invention formula

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1. A method for degassing excavation fields in a pillar-based development system that includes drilling in a plane from a haulage and / or vent

Q drifts of parallel wells before carrying out cleaning works, sealing wells and connecting them to the degassing pipeline connected to the vacuum system, gas suction

j from the reservoir and measuring its flow rate, characterized in that, in order to increase the efficiency and efficiency of the degassing method by providing the opportunity to use for the degassing of the developed space of spent lava wells that have degassed the previously developed reservoir, at the end section

gj of the flank development along the worked-out column, at the same time through sections of the wells, drawn along the worked-out column, left in 51. The pillars, on completion of the work of the lava, ensure the suction of gas from the worked-out space. 2. The method according to claim 1, characterized in that, in order to maximize the degassing efficiency of the low gas permeability formations, the drilling of parallel wells from the haulage and / or ventilation drifts is carried out with a reversal on the mining face, while the wells running along the flank production, drilling of variable length with a shortage of 5ft to the last well from the system of the previously mentioned wells for a distance equal to the distance between the wells, drawn from the ventilation and / or backing lines. 3. The method according to paragraphs. 1 and 2, so that, in order to reduce air inflow into the degassing pipeline when an aerodynamic connection of wells occurs to the bottom hole of the active lava, the vacuum at the wellheads distributes the proportional gas flow rates

Claims (3)

formula ^- inventions 1. A method of degassing excavation fields with a pillar development system. ^ Including drilling in the plane of the reservoir from the recoil and / or ventilation drifts of parallel wells before cleaning, sealing the wells and connecting them to a degassing pipe in communication with the vacuum system, suctioning gas from the reservoir and measurement of its flow rate, characterized in that, in order to increase the efficiency and economy of the degassing method by providing the possibility of using the working space for degassing at the end of the excavation field, the wells are drilled from the flank hole along the worked column, while through the sections of wells conducted along the worked column. left in the pillars, at the end of the lava work, gas is sucked from the produced space. 2. The method according to claim 1, characterized in that, in order to increase the efficiency of degassing of formations with low gas permeability, the drilling of parallel wells from the recoil and / or ventilation drifts is carried out with a turn on the face, while the wells along the flank of the production, drill variable length with a bit 1268745 6 to the last well from the system of the previously mentioned wells by a distance equal to the distance between the wells conducted from the ventilation and / or 5 recoil drifts. 3. The method according to PP. 1 and 2, which is different in that, in order to reduce air leaks into the degassing pipeline when 10 of the aerodynamic connection of the wells with the bottomhole space of the active lava, the vacuum at the mouths of the wells is distributed in proportion to the gas production