Experimental Study Of Hydraulic Punching Pressure Relief And Gas Extraction In The Low Gas Permeability Coal Seam

With the increasing of the depth of mining,high gas and low permeability coal seam has been widespread among the various mines,which is seriously restricting the safe and efficient mining coal.For low permeability coal seam.This paper think that implementing effective antireflective measures and increasing the efficiency of coal seam gas extraction are effective methods of the prevention and control of coal and gas outburst and improving coal safety.Due to the advantages of the hydraulic punching,simple operation,safe and reliable,the measure has been widely used in high gas and low permeability coal seam. Mainly through theoretical analysis, numerical simulation and field of industrial test, This paper analyzed and studiedthe implementation of hydraulic punching antireflection measures.In the low permeability coal seam, on the basis of summing up the existing hydraulic punching AR technology,this paper further analyzed and summarized the dynamic characteristics of water jet in Hydraulic flushing,the affecting factors about the water jet of the breaking coal and some common coal mass failure criteria and the mechanism of breaking coal of the water jet etc, At the same time, simulating the process of the water jet breaking coal and the stress and strain of the coal body around the measuring holes before and after hydraulic punching through ANSYS/LS-DYNA finite element software, the author implemented hydraulic flushing field experiments in the11-2Coal seam of the DINGJI Coal Mine. Based on observations of gas extraction concentration and gas extraction pure quantity before and after hydraulic flushing, the field experiments further validated the antireflection effect of the hydraulic punching,besides providing reliable scientific experimental basis for the technique of large scale construction in the mine.Figure [30] Table [7] Reference [53]...