Control Of Geological Strcures On Gas Storage And Distrbution Of Coal Seams

The gas that refers to all the harmful gases in coal mine is mainly generated because of coal metamorphism, and the conditions of gas storage and distribution are closely related with the function of tectonic movement after coal formation. With coal mining deeply, the gas issue of Renlou mine is gradually outstanding, such as gas gushing abnormally, which has impacted on the normal exploitation of mine. The purpose of this research is that, according to gas data of coal seam 7₂, 7₃ and 8₂ as well as the geological structural feature in the Renlou mining area, to study the control of geological structure on gas, to know gas distribution law and storage state, to predict gas content and gushing quantity of deep-seated well field, to prevent the mine gas calamity and guarantee the safety in production of mine.On the basis of the principle for the function of control on coal and rock mass of geological structures so as to influence gas storage and distribution, a large number of coal seam gas and exploratory boring data were collected, many indoor tests and in situ testing were carried on at the same time. And the method of mine statistical analysis and geological structure unit divide was adopted to research the gas geological characteristics of mainly mining coal seams. By the application of the correlation analysis approach in geological statistics to the control of geological structure on gas content, composition and emission, combined with collecting rate of drill core, several mathematic equations were obtained after regression analysis. The influence of minor faults on gas gushing and coal body structures is the key of this paper.The conclusion drawn from present research shows Renlou coal field is in a state of half open because of subsequent tectonic movement, and the conditions of gas storage is poor so that gas contents of coal seams here are much lower than others, otherwise different structural conformations made gas emission unusual in fractional area of the coal mine, gas contents increased with burial depths of coal seams by degrees. To the fault whose throw is greater than 15 meters, there are two types of faults in the ore district. One is extension fault whose collecting rate of drill core is smaller than 75 percent, methane (CH4) content of coal seam is less than 60 percent, and nitrogen (N₂) content is greater than 30 percent, that the gas content is low. The other is compress o-shear fault whose adopting rate of is above 80 percent, and the gas...