Application research on gas drainage technology at low permeability coal seam
Abstract
Gas drainage at low gas permeability coal seam is a main barrier affecting safety and efficient production in coal mines. Therefore, the research and application of drainage technology in low gas permeability coal seam is a key technical for coal mine gas control. In order to improve the drainage effect, this paper studies the changes of original stress field, displacement field, gas pressure field and gas movement field inside the overburden rock around the goaf, and establishes a three-dimensional solid-gas-liquid coupling numerical model. Then the numerical simulation analysis for regularity under condition of coupling of released rock and fluid are conducted. This paper comprehensively analyzes the stress and fissure variation regularity during coal extraction in deep mines, as well as the scope of released gas movement, enrichment range and movement regularity during coal mining. It can provide reference for prediction of gas emission from deep coal seam mining, and help to design efficient coal mine gas drainage. Yangquan mine area is chosen as the research target, and the gas movement regularity and emission characteristics are studied. Then the gas drainage technology and parameters for the current coal seam are studied. After measuring the gas drainage amount in-situ, it was found that the technology can achieve notable drainage results, gas drainage rate increase by 30%~40%, for low permeability coal seam.References
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