Application of large borehole pre-extracting gas technology in low permeability and high adsorption coal seams
Mine gas is the top five major disasters in coal mines,and gas extraction is the most effective means of gas con-trol.The difficulty of gas control in low permeability and high adsorption coal seams is relatively increased.We use on-site measurement methods to obtain the permeability coefficient and gas flow attenuation coefficient of the 4304 working face of Jianxin Coal Mine.Based on the characteristics of the coal seam and the analysis of the extraction radius parameters,a plan for pre-extraction of coal seam gas through large aperture drilling has been developed with good gas control effects.The gas flow attenuation coefficient of the 100 meter borehole in the mine is 0.032,and the permeability coefficient of the4-2 coal seam is 0.506.The coal seam belongs to a low permeability coal seam.By implementing the technology of pre-extraction of gas through large-diameter and long-distance drilling in low permeability and high adsorption coal seams,the gas concentra-tion in the corners of the fully mechanized top coal caving face during mining is between 0.14%and 0.39%,and the gas concentration in the return air flow is between 0.12%and 0.17%,achieving safe and efficient production in the face.
mine gasgas adsorptiongas extractionpermeabilitydrilling along layers
国家科技期刊平台
NSTL
万方数据
维普
