Method for fast extracting gas on coalface

Abstract

The invention discloses a method for fast extracting gas on a coalface. The method includes that a bottom extraction roadway with the distance to a coal seam no smaller than 5 m is tunneled on a coal seam floor; a plurality of fracture drill holes extending into the coal seam are formed in the bottom extraction roadway, the center distance between every two adjacent fracture drill holes in the position entering the coal seam is between 30 m and 50 m, and the depth of the fracture drill holes in the rock stratum is not smaller than 10 m; the fracture drill holes are sealed according to fracture sealing requirements, and the coal seam is hydraulically fractured; the fracture drill holes are connected with an underground gas extraction system of a coal mine, and then coal seam gas can be extracted; a plurality of extraction holes extending into the coal seam are formed in the bottom extraction roadway, and the center distance from any extraction hole to the adjacent extraction holes or the position for the corresponding fracture drill hole to enter the coal seam is between 5 m and 8 m; the extraction holes are sealed according to extraction sealing requirements; coal seam gas is extracted through the extraction holes till the coal seam gas content reaches the standard. The method for fast extracting gas on the coalface has the advantages of having fewer drill holes and being high in extraction efficiency and coal mining efficiency, and roadway tunneling and coal mining work can be performed safely.

Description

technical field [0001] The invention relates to a coal seam gas extraction method, in particular to a quick gas extraction method in a coal mining face. Background technique [0002] Coal seam gas is a kind of clean energy, but it is also a source of disaster for coal mine production. The geological conditions of coal occurrence in my country are complex, mainly relying on underground mining. With the increase of mining depth, the gas content of coal seams gradually increases, the pressure of coal seam gas increases, the risk of outburst increases, and the difficulty of outburst prevention becomes more and more difficult. The gas drainage in the existing coal mining face is carried out by drilling bedding holes in the coal seam in the transport roadway and the air return roadway respectively. In the tunneling of soft outburst coal roadways, collapsed holes, spray holes, pinched drill holes and top drill holes often occur, which may even cause coal and gas outbursts, resulti...

AI Technical Summary

Problems solved by technology

In the tunneling of soft outburst coal roadways, collapsed holes, spray holes, pinched drill holes and top drill holes often occur, which may even cause coal and gas outbursts, resulting in short drilling distances, and the drilled holes are out of shape and exhausted. And the coverage of pressure relief is small, and the excavation speed is slow

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