Dynamics of Coal-Measure Gas Co-Accumulation

Given the extremely low proven rate of coal-measure gas (CMG) in China, this review treats CMG as an integrated whole to analyze its co-accumulation dynamics, building upon its fundamental differences from conventional oil and gas accumulation. It systematically evaluates the geological controls, dynamic mechanisms, and qualitative and quantitative research methods of CMG co-accumulation reservoirs. Based on superimposition characteristics, CMG reservoirs are classified into three types. Relevant studies highlight that the CMG co-accumulation process is profoundly governed by extreme reservoir heterogeneity, leading to the formation of distinct diffusion and seepage pore systems within the porous media. Currently, although traditional qualitative analysis methods for CMG accumulation are relatively mature, quantitative research still holds significant room for advancement. In light of this, key future research directions are proposed, aiming to provide a theoretical foundation for the efficient co-exploration and co-exploitation of CMG.