Improved Relative Permeability Models Incorporating Water Film Effects in Low and Ultra-Low Permeability Reservoirs

To advance the modeling of low and ultralow permeability reservoirs, this research innovatively introduces new relative permeability models that incorporate water film effects, aiming to accurately capture intricate variations observed in experimental data. We analyzed the primary influencing factors and roles of water film effects in porous media. Our findings show that the new models provide enhanced and more robust fitting performance for both gas and liquid phases, with wider applicability, especially in low and ultralow permeability reservoirs. Incorporating water film effects into modeling offers a detailed and efficient approach to understanding their influence on fluid flow capacity in porous media. We also propose using the copermeation triangular area as a distinctive quantitative indicator for evaluating two-phase fluid flow capacity in porous media with varying properties. This approach addresses the lack of a comprehensive quantitative indicator for the flow capacity of two-phase fluids in porous media, demonstrating significant practical value. This study contributes by highlighting the crucial role of water film effects in accurately modeling fluid behavior in porous media, enhancing our understanding of the microscopic controlling mechanisms of fluid flow behavior within porous environments and providing detailed insights into relative permeability model selection for fluid flow modeling.