Coupling the Dynamic Contact Angle into the Dynamic Imbibition Model for Fractal Porous Media

Abstract

This study aims to develop a fractal model for the dynamic imbibition (DI) process in tight porous media. We developed the model by coupling the dynamic contact angle (DCA) into the DI model at capillary and core scales. A numerical method was proposed to solve the developed model. We then validated the model against experimental data reported in the literature. The results show a relatively satisfying fitting between our DI model and experimental data. We also compared the imbibition rate and oil recovery predicted by the DI model considering and not considering the DCA. The results indicate that considering the DCA improves the DI model's accuracy, whereas neglecting the DCA results in the overestimated imbibition rate and oil recovery for the DI process. We conducted sensitivity analysis to evaluate how the contact angle, interfacial tension, and displacement pressure affect our DI model's performance in calculating imbibition recovery. The results show a relatively more significant difference in imbibition recovery determined by DI models considering and not considering the DCA at a relatively high contact angle, a relatively high interfacial tension, and a relatively low displacing pressure. This study highlights the importance of considering the DCA in DI modeling for fracturing practices which associate with surfactant injections to alter wettability and reduce interfacial tension in tight reservoirs.