Regional forced gas extraction method for single low-permeability outburst thick coal seam

Abstract

The invention provides a regional forced gas extraction method for a single low-permeability outburst thick coal seam. The regional forced gas extraction method comprises the steps of (a) excavating a rock gangway in a rock fissure zone and drilling a lower-position seam through hole downwards, (b) drilling a high-position seam through hole downwards in the rock gangway, (c) starting a high-pressure water-injection pump station, performing hole expanding operation on the coal seam through sections of the drilled holes under the conditions of the water pressure of 10-20MPa, the flow rate of 8m<3> / h and the single-hole coal output greater than 5t, (d) sealing the drilled holes and carrying out drainage strip networking extraction operation after the hole expanding operation is finished, (e) after the extraction is up to the standard, carrying out tunneling operation of an air return way and a transportation roadway, and meanwhile, drilling a bedding pre-extraction hole in the working face and carrying out the hole sealing and networking extraction operations, and (f) continuously extracting the gas of the goaf in the rock gangway during the recovery of the working face. The regional forced gas extraction method is capable of converting a high-gas outburst coal seam into a low-gas outburst risk-free coal seam, comprehensively guaranteeing safe production of the working face, and meanwhile, obviously increasing the coal roadway tunneling speed.

Description

technical field [0001] The invention relates to a regional gas enhanced drainage method for a single low-permeability protruding thick coal seam. Background technique [0002] The existence of mine gas is the root cause of gas explosions and coal and gas outburst accidents, which seriously threaten the safe production of coal mines. my country's "Provisional Regulations on Drainage of Coal Mine Gas Drainage Standards", which came into effect on March 1, 2012, clearly stipulates that the coal seam that should be drained must first drain the gas, and the mining operation can only be arranged after the drainage effect meets the standard requirements. Drainage should adhere to the principle of "should be exhausted, multi-measures should be taken simultaneously, and extraction should be balanced". [0003] With the increasing scale of coal production in my country, the level of mine mining continues to expand, and the proportion of high-gas and low-permeability coal seams, especi...

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Problems solved by technology

[0004] In order to ensure safe, efficient, and uniform gas extraction in a single thick coal seam, transform the high gas outburst coal seam into a low gas outburst non-outburst dangerous coal seam, increase the speed of coal roadway excavation, and solve the difficulty of gas drainage in thick coal seams to meet the standards, the enhanced anti-permeability measures are adopted. In view of the difficulties in coal seam drilling and construction, the present invention provides a regional gas enhanced drainage method for a single low-permeability protruding thick coal seam

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