Geological factors of gas anomaly of seam 8 in Donghuantuo mine of Kailuan mining area

In this paper, geological factors controlling abnormal gas emission in Donghuantuo coal mine were analyzed. We used mercury intrusion method and isothermal adsorption method to study the characteristics of coal reservoir in combination with measurement data of gas emission. Results indicate that the geological structure and hydrogeological characteristics are the main geological factors and the distinctive occurrence regularity of Donghuantuo coal mine is that when water is high, gas is low, and vice versa. The occurrence of mine gas is mainly in the form of free state, and when gas occurs in the compression fractures, gas emission is smaller; in the case of non-conducting coal measures aquifers, fault zones often lead to coal crush and relatively developed fissure, the gas emission significantly increases; in the case of conducting coal measures aquifers and hydrological abnormal area, the gas emission significantly decreases. Gas emission of Donghuantuo coal mine is controlled by many factors. So we select coal seam buried depth, coal seam thickness, the mud content of coal seam roof and the number of faults as the main control factors, and then set up a mathematical prediction model which has a good correlation between the gas emission and multivariates. And through the grey system theory modeling software, the correlation between gas emission and multivariates was analyzed, finally it was found that the fault is the main influence factor of gas emission.