DIRECT PORE-SCALE MODELING OF TWO-PHASE FLOW: INVESTIGATION OF THE EFFECT OF INTERFACIAL TENSION AND CONTACT ANGLE

The process of fluid flow displacement in porous media has recently gained great prominence owing to its widespread usage in a variety of industries, especially in the case of pore scale investigations. Although, many studies have been conducted to address pore-scale investigations in both modeling and experimental approaches, the role of interfacial tension and contact angle on pore-scale phenomena is less focused. In this work, direct pore-scale modeling was used to precisely examine the effect of interfacial tension and contact angle on the fluid flow at the microscale. Also, several pore-scale mechanisms, including Haines jump and dynamic breakup mechanisms, were observed. Therefore, the volume of fluid method, as an astonishing free-surface modeling method, was utilized in an open-source finite-volume computational fluid dynamics software package (OpenFOAM). To validate the simulation results, we designed and performed a set of corresponding micromodel experiments. The investigation of the effect of interfacial tension illustrated that when interfacial tension is decreased, a thin film of the wetting fluid propagates along the solid surface. At high interfacial tension (capillary numbers less than 6 x 10(-4)) cooperative pore filling was observed, while at low interfacial tension large deformations were obvious. Also, when the contact angle was less than 90., cooperative pore filling was the main mechanism, while at contact angles greater than 90. individual pore invasion was the active mechanism.