Research on geological characteristics of gas occurrence in Huoshaopu mine field of Panguan Syncline

In order to find out the gas geological characteristics, control factors and enrichment rules of Huoshaopu mine field,so as to provide design parameters for ground coalbed methane exploration project deployment, provide reference for gas outburst prevention, outburst elimination design and engineering treatment in production mines. Firstly, combined with the results of previous surface borehole gas tests, the geological supplementary exploration project of surface gas is deployed in the deep part, and various technical means such as geological drilling, sampling test, gas logging, injection pressure drop test, adsorption and desorption are adopted to comprehensively analyze the distribution characteristics of gas in each coal seam in the horizontal and vertical directions.Secondly, the key parameters such as gas content, pressure, solidity coefficient f value, initial gas diffusion velocity ΔP, adsorption constants a and b value of each coal seam in the production mine are systematically tested, analysis and evaluation of outstanding risks. Finally, it points out the exploration and development direction of coalbed methane and puts forward three kinds of measures to prevent and eliminate gas outburst in mines,taking production mines as test objects, it compares and analyzes the engineering application effects of the three measures. The results show that the natural gas composition in the mine field contains a certain amount of C2～C8, and there are local abnormal enrichment areas, and the content is positively correlated with the coal seam depth.Although the occurrence of gas is controlled by three factors: structure, burial depth and hydrogeological conditions, it is mainly controlled by the burial depth of coal seam.The coalbed methane resources in the mine field have certain development potential.The stranded area in the shallow part of the two wings of the syncline and the deep part of the syncline axis are favorable areas for coalbed methane exploration, and the middle and upper coal formations are favorable horizons.Production mines can give priority to the mining of protective layer, and at the same time cooperate with top and bottom drainage tunnels, strip pre-drainage, along-layer long borehole drainage and other three measures to eliminate outburst and prevent outburst in the mine area. Comparative analysis of engineering application results shows that along-layer long borehole drainage technology has the best effect.