Cross drilling constrained expansion network anti-reflection gas drainage method

Abstract

The invention provides a cross drilling constrained expansion network anti-reflection gas drainage method, and belongs to the technical field of coal rock gas drainage. The method is characterized by comprising arranging cross drill holes on a thick coal seam whose permeability is low, an upper row of the cross drill holes being gas drainage cross drill holes, a lower row of the cross drill holes being arranged with the gas drainage cross drill holes and blastholes at interval, fixing blasting cartridges in a constraint manner on intersection positions of the lower row blastholes and the upper row gas drainage cross drill holes, to apply anti-reflection blasting to generate network cracks. A water bag is used to separate two blasting cartridges, and the water bag suppresses expansion and reduces dusts and can cuts apart a coal and rock mass, to form an effective drainage crack. Using the method can achieve objectives of increasing permeability of a coal seam, increasing gas flow of a cross drill hole drainage hole and prolonging effective duration time of gas drainage flow, and the method would not excessively damage a coal mass.

Description

technical field [0001] The invention relates to the technical field of coal and rock gas drainage, in particular to a gas drainage method used for anti-permeability enhancement of a cross-drilled constrained blasting network in a low-permeability thick coal seam. Background technique [0002] In recent years, my country's coal production has been increasing day by day, the mining depth of coal mines has increased year by year, the gas content in coal seams has increased, the amount of gas emitted from coal seams has increased during the mining process, and even some coal mines have significantly increased the risk of outbursts, seriously affecting the safe and efficient production of coal mines. Only by draining the coal seam gas and reducing the gas content in the coal seam can the gas risk be reduced. [0003] The main factor affecting the coal seam gas drainage effect is the permeability. At home and abroad, hydraulic fracturing, hydraulic slotting, deep hole loosening bla...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies and defects of the prior art, and to provide a gas drainage method suitable for low-permeability thick coal seam mines to solve the problem of poor gas drainage effect in low-permeability thick coal seam mines

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