Gas Extraction Effects of Multiple Boreholes under Dual-medium Porous Model
To study the extraction effect of negative pressure drilling in gas-containing coal bodies and understand the effective extraction range of drilling in arranging multiple boreholes,taking a mine as the research background,this paper constructs a gas-solid coupling model based on the gas flow theory under the pore-fissure dual-medium porous model.Combined with the ac-tual production,we used COMSOL numerical simulation software to study the effective extrac-tion radius of the single bedding borehole.Taking the borehole spacing as the design premise,we studied the multiple borehole effects of parallel arrangement in the effective drainage range.The results show that when the extraction duration is 150 days,its effective drainage radius is approx-imately 1.1 m;with borehole spacing of 1.56 m,2.20 m,3.00 m,4.00 m,and 5.00 m,the gas extraction effect is enhanced to different degrees due to the interaction between boreholes.There-fore,different borehole spacing can be set according to the coal seam structure and the actual pro-duction conditions.
gas extractiongas-solid coupling modelborehole spacing
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