Reservoir Simulation of the Antrim Shale in the Michigan Basin

Abstract

ABSTRACT This paper presents the results from a preliminary investigation into the reservoir mechanisms controlling gas production from the Antrim Shale of the Michigan Basin. We used a two–phase, dual porosity, finite– difference reservoir simulator incorporating shale– specific reservoir characteristics to match a well's gas and water production history. We also analyzed the sensitivity of Antrim Shale gas production behavior to drainage area and several reservoir properties. The results indicate that long–term gas production from the Antrim Shale is primarily controlled by natural fracture properties, desorption properties, and drainage area. Based on development strategies for coalbed methane reservoirs, there is an optimum well spacing for effectively dewatering the Antrim Shale, thus accelerating gas production and improving ultimate recovery. Finally, we found that shale matrix diffusion properties have little effect on short–term gas productivity, and preliminary results also suggest long–term gas productivity does not depend on matrix diffusion.