SU1585538A1 - Method of controlling gas emission in excavation of protective undermined bed - Google Patents

Abstract

The invention relates to mining. The goal is to reduce the cost of degassing and simplify the management of gas emission during the development of a protective additional layer. From the nearby workings of the drilling of the well into the roof of the undermined reservoir to the approach of the cleaning hole of the protective formation. The downhole wells are located above the fault zones of the main roof. In the wellsides, fracture zones are formed by softening. After the roof of the undermined seam is softened, the wellbores below the reservoir are sealed and can be used as degassing ones. These wells begin to work efficiently immediately after the roof is softened, which increases the period of effective operation of the drainage wells. 2 Il.

Description

The invention relates to the mining, mainly coal, industry and can be used in the development of a protective undermining layer.

The purpose of the invention is to reduce the cost of degassing and simplify the management of gas emission during the development of a protective working layer.

Fig. 1 shows a diagram of the application of the method in a section parallel to the clearing face: Fig. 2 shows a diagram of the application of the method in plan.

The method is implemented as follows.

As a result of working out the protective stratum 1, a zone of complete collapses 2 to a height up to a storage capacity (t) is formed in the developed space. Over this

a zone forms a zone of fractured rocks 3 to a height of up to 100-110 SW, gas is drained from these high-gas undermining reservoir 4 in these zones, because the fracture of rocks is greater, the closer to the reservoir being worked, the gas mainly enters into the developed space and additionally aerates the production of a protective stratum, which hinders its development.

In order to reduce the gas content of the workings of the protective stratum of them, mainly from the ventilation outlets, the well 5 is drilled through the undermining stratum 4 above its roof.

The wells are drilled prior to the start or approach of the refining works to the zone of formation of the greatest fracturing — to the zone of complete displacement. The wells are located after CX)

cl

SL) 00

in pairs, with the bottom of one well closer to the reservoir, and the other farther away. Depending on the method of softening and its ability to crack formation, the main parameters of the created zone of increased fracturing in the roof are determined.

The main parameters of this zone include the frequency of the fractures, as well as the distance from the reservoir to the mouth of a nearby well, from the mouth of the latter to the mouth of the remote well, and between pairs of wells. The zone to be formed should be at some distance from the reservoir in order to prevent the formation of an unstable direct roof above it, as well as to have a sufficient protrusion and degree of weakening for the predominant gas drainage to the roof.

After the roof of the undermined seam is softened, the wellbores below the reservoir are sealed or can be used as degassing, which begin to work effectively immediately after the roof has become weak, i.e. the period of effective operation of the drainage wells increases. As a result of the weakening of a number of well pairs, a zone of high fracture 6 is formed in the top of the producing reservoir, and gas from the reservoir drains into the roof. After working the reservoir 4 in zone 6, the cracks open up even more and the fracture of the roof rocks significantly exceeds the fracture of the soil rocks. Therefore, the drainage of gas 7 into the roof significantly exceeds the drainage into the soil (Fig. 1).

When mining the formation in the massif lying above the main roof, the main mass of cracks is formed at the time of the collapse of the main roof. As a result of the first precipitation (precipitation step 1b), the main roof is divided into 2 blocks, forming fracture cracks along the edges of the crush and in the middle. Subsequently, after a certain step of 1 r, a periodic slump of the main roof occurs with the formation of the same fracture cracks. These fracture cracks are the most dangerous gas drainage channels in the 8th reservoir generation. Above the main roof in weaker rocks adjacent to the undermined formation, cracks are formed everywhere in the zones of development of displacement, but most densely in the areas of fracture of the main roof. Therefore, in order to reduce the volume of drilling, it is recommended to weaken the roof of the undermined formation only in fracture areas main roof (figure 2).

Claims (1)

Another example of the application of this method of gas emission control during the development of a protective formation in the case of underworking could be the drilling of wells from productive workings or formations, passed through both protective and undermined formation into the roof of an undermining formation, and its further softening. Claims The method of controlling the emission of gas during the development of a protective undermining layer, including the drilling of wells in the top of the reservoir from nearby workings to the approach of the clearing hole and the formation of a zone of cracks by weakening, in order to reduce the cost of degassing and simplify - 35 neither by gas release during the development of a protective additional layer, wells are drilled into the roof of the reservoir being mined, and the bottom holes are positioned over the fault areas of the main roof o layer. fig 1    g - ). /   -, - - -Sj / uA .r (..,   n 7- .., AVy / - ./X  V -, H - L ., v, u .vvl l; g., -.V v) -ixcyvC, HCH- /, TV iC, / i / g 2