Simulation of methane adsorption in diverse organic pores in shale reservoirs with multi-period geological evolution

Abstract In shale reservoirs, the organic pores with various structures formed during thermal evolution of matter are main storage site for adsorbed methane. However, in process evolution, adsorption characteristics methane multi type and multi-scale have not been sufficiently studied. this study, molecular simulation method was used to study based on geological conditions Longmaxi Formation reservoir Sichuan Basin, China. The results show that pore structure will affect characteristics. capacity slit-pores is much higher than cylindrical pores. groove space inside change density distribution molecules pore, greatly improve increase pressure sensitivity process. Although variation different shapes consistent size, all strongest when size about 2 nm. addition, changes temperature also important factors control first increases then decreases pressure, temperature. early stage strong weak; while late stage, it contrary.