The Research On Methane Gas Storage And Distribution Features Of No. B₄ Coal Seam In Fengcheng Mining Area

According the gas content of and research data measured during proving and production of B4 mine seam in Fengcheng Coal Field, comprehensive analysis of the geological factors of gas occurrence in the study area, finding out distribution of gas content trends in this area the, some research results was made out. It performed in the following four aspects:(1) Combined the coal seam depth with the gas content contour map of B4 coal in the study area exploration, the reason of the reducing gas content in the southern of syncline in eastern Qujiang:the coal seam in the area uplift and constantly subject to erosion under the tectonic, and the faults in this area are generally open faults; these are the ultimate reason of low gas content in the deep coal seam in this area.(2) Geological structure plays a leading role in gas occurrence and growth degree of B4 mine seam. The break complexity coefficient was used to comprehensively evaluate the faults, folds, seam dip, and other related parameters in the study area, then combined with mine gas content, coal and gas outburst and other basic information to divide B4 coal seam in the Fengcheng coal mine. The results show that:this area is divided into five gas geological unit, II and III area belong to the low gas content, I and IV area belong to the high gas content area, V belongs to the normal gas content area. The main factors of gas occurrence in this area are Qujiang syncline, Niufang county anticline and a series of opening, tensor-shear,closeing,compresso-shear and intensive small and medium pressure shear small faults.(3) According to gas occurrence and distribution, the main geological factors of gas outburst in the different geological units, the factors of dense gas occurrence, high intensity outstanding and dense outstanding point are analysed and explored. It is of great significance to guide coal gas hazard prevention and control.(4) Comprehensively analysing the factors of gas occurrence and distribution of coal seam rock property, coal depth, coal metamorphism, the thickness of the overlying rock and other important factors, the results indicate that:the gas content in the study area is wholly increasing as the coal seam depth increasing, the sealing properties of the top floor rock densification and incrassation and the vdaf reduce; the gas content shows a significant gradually increasing trend from south to north, from east to west.