'Three-soft' low permeability high gas coal seam rapidly digging method

Abstract

The invention discloses a method for rapidly digging 'three soft' low permeability and high gas coal layer, which comprises the steps of arranging a stone head in a bottom plate rock under the coal layer, and constructing pre-extracted penetrating drill holes of gas in the bottom plate rock layer and pulling the bit back to the bottom plate of the coal layer after the bit penetrates the coal layer, and punching the drill holes by pressure water with the depth of the punching holes being less than or equal to three meters, and the control radius of the punching holes being from two to six meters to realize continuously, draining gas in the holes, and stopping draining while the gas draining amount is at 0.1 cubic meter per hour; injecting water to the coal layer by using the drained gas drill holes, with water injection pressure controlled between ten to fifteen Mpa, and stopping water injection when the water injection effect reaches the demands of construction in coal layer; and draining goaf by the drill holes after extraction in mining face. The digging method increases the resolving speed of the 'three soft' low permeability coal layer gas, improves the gas draining effect and realizes the low gas construction in the high gas coal layer and one hole for three purposes, not only ensures the safety during construction, but also improves the digging speed in the roadway maximally.

Description

Technical field: [0001] The invention relates to a coal seam excavation method, in particular to a rapid excavation method suitable for "three soft" low-permeability and high-gas coal seams with soft coal quality. Background technique: [0002] The coal quality is soft and suitable for hand-picking coal, and the coal quality is small or powdery, which is prone to roof leakage; the coal seam is dry, and the working flour is dusty, so the coal seam must be filled with water before tunneling, otherwise construction cannot be carried out. Because the coal is soft and the gas release drilling and the roadway pre-drainage drilling cannot be constructed due to serious hole collapse, the roadway excavation process will be severely restricted by gas; the surrounding rock of the roadway is soft and the pressure is high, and the maintenance of the coal roadway is difficult, and it is difficult to arrange Long-distance excavation face. During the construction of the excavation face, th...

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Problems solved by technology

[0004] In order to solve the problem that the excavation speed of the "three soft" coal seams is slow and the gas cannot be removed in time, the purpose of the present invention is to provide a coal seam with fast excavation speed, timely discharge of coal seam gas, suitable for soft and soft coal seams, improve coal seam excavation efficiency, and improve coal seam excavation safety. Innovative rapid excavation method for "three soft" low-permeability and high-gas coal seams

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