Low premeability high gas soft thick coal layer remote pressure relief gas exhausting method

Abstract

A remotely pressure-releasing method for sucking and exhausting gas from the low-air-permeability high-gas soft and thick coal seam is disclosed. The coal seam, which is 70m under the coal seam to be gas-exhausted and has relative interbeam distance of 30-70 times, is first mined. Under the action of pressure release and subsidence, the cracks are generated in the coal seam and the gas penetrates through the cracks and then is exhausted via predrilled holes. After the coal seam is mined, a great deal of gas is flowing along the seam and then is sucked by said predrilled holes.

Description

Technical field: [0001] The invention relates to a coal mine safety production method. More specifically, it is a coal seam gas pre-extraction method. Background technique: [0002] Anhui Huainan Mining Area is located in the hinterland of East China and is an important energy base in my country. The mining area is rich in coal resources, with a large number of mineable coal seams, and the pressure-relieving coal seams are stable and thick. The average thickness of the 13# coal seam in the main mining area of ​​the Huainan mining area is 6m, the original gas pressure of the coal seam is 4.4MPa, and the gas content is 13m 3 / t, coal seam permeability coefficient is 0.01135m 2 / (MPa 2 .d) is a typical low-permeability and high-gas soft thick outburst dangerous coal seam. During the mining process of this coal seam, coal and gas outburst accidents and large gas explosion accidents that caused many deaths occurred many times. Facing to the gas emission 25m 3 / d, the gas c...

AI Technical Summary

Problems solved by technology

Among them, the roof high roadway method is to arrange the drainage roadway in the crack zone of the roof, and the pressure relief gas gathers to the drainage roadway along the flow channel formed by the vertical fracture crack. This method has a good effect on the coal seam in the crack zone. However, for the pressure relief coal seam in the curved subsidence zone, since there is no vertical fracture gap, it is impossible to form the flow conditions for the gas to gather along the interlayer to the high-level drainage roadway, so the pressure relief coal seam cannot be effectively pumped gas

Roof long-distance through-bed drilling method is to drill long-distance through-bed drainage drilling holes from the mining coal seam return airway to the pressure relief coal seam. Since the drilling holes have to pass through the collapse zone, the drilling holes will be connected to the goaf. short circuit, so this method cannot effectively drain the gas from the remote pressure relief coal seam

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