Evaluation of coalbed methane extraction effect based on 3D geological modeling technology: An example of Sihe Mine in Jincheng City

Three-dimensional geological modeling can intuitively and visually evaluate the effect of coalbed methane(CBM) dynamic drainage, and provide guidance for subsequent adjustments to development plans. With the help of 3D geological modeling software, No.3 Coal Seam of west-second panel is taken as the research object. A geological model that can reflect the spatial geometric changes and structural characteristics of coal seams, and the dynamic changes of coal reservoir attribute parameters is established based on the analysis of geological and productivity data and numerical simulation, to realize the dynamic evaluation of the CBM extraction effect in the study area. The constructed three-dimensional geological model is used to predict important parameters such as gas production, reservoir pressure distribution, and remaining gas content. The results show that the average daily gas production predicted in different drainage cycles of the CBM wells in Sihe Mine will gradually decrease, and the scope of influence will gradually expand. The average reservoir pressure in the study area will drop from 1.31 MPa in 2010 to 0.60 MPa in 2022, a decrease of 54% from 2010. The average remaining gas content in the study area will drop from 15.70 m³/t in 2010 to 5.65 m³/t in 2022. It provides a scientific basis for the application of the three-dimensional geological model in the effect evaluation of CBM extraction in a factual and objective way.