Characteristics of groundwater dynamic field and its effect on coalbed methane accumulation in Songzao mining area

Songzao mining area is one of the most abundant coalbed methane resources in China. In order to reveal the characteristics of groundwater and its effect on coalbed methane enrichment in Songzao mining area, the hydrogeological data obtained from coal field exploration, based on the analysis of aquifer structure, water chemistry characteristics and pumping data, the distribution pattern of groundwater was established, and the influence of groundwater dynamic field on coalbed methane enrichment was discussed. The results show that aquifers are overlapped with each other in Songzao mining area, and the water content is weakened with the increase of the buried depth. The coal-bearing rock series and the overlying and underlying aquifers are lack of hydraulic connection and are independent of the water system. There are three types of groundwater dynamic field in Changxing Formation and Lower Maokou Formation, and the groundwater dynamic field has three types:karst fissure infiltration type, fault communication karst fissure recharge type, stable pressure weak water type, stable weakly aquiferous type is dominant, and the weak water-bearing property of coal-bearing rock series and its lack of hydraulic connection with overlying and underlying water-bearing strata constitute the basis of hydrogeological control of gas in the area, is an important control factor.