InterPore2026

Mixed Wettability in Microfluidic Systems: Experimental and Numerical Insights into Two-Phase Fluid Flow

20 May 2026, 14:50

15m

Oral Presentation (MS05) Physics of multiphase flow in diverse porous media MS05

Speaker

Abdullah AlOmier (Saudi Aramco)

Description

Subsurface reservoirs often exhibit complex wettability patterns, which significantly impact multiphase fluid flow and entrapment. Microfluidic systems have emerged as a key tool for studying pore-scale fluid dynamics; however, creating devices with controlled mixed wettability has been a challenge. This study presents a novel technique for fabricating micromodels with controlled mixed wettability using photolithography and molecular vapor deposition. Six distinct micromodel configurations were designed to mimic the complex wettability variations found in natural porous media, including single channels, Y-shaped channels, and mixed-wet pore-doublet models with different wettability orientations. Two-phase flow experiments were conducted using a high-resolution microscope and high-speed camera, providing dynamic insights into the influence of mixed wettability on fluid flow. Pore-scale simulations were performed using the phase-field approach in COMSOL Multiphysics to replicate and validate the experimental findings. Experimental observations revealed a significant impact of mixed wettability on two-phase fluid behavior. Notably, meniscus shapes underwent a shape change as fluids moved between hydrophobic and hydrophilic areas. The fluid interface adopted a distinctive S-shape in channels with vertical mixed wettability variations. Furthermore, wettability guided the flow direction in hydrophilic channels while bypassing hydrophobic ones in Y-shaped micromodels. The mixed-wet pore-doublet models demonstrated that fluid initially invaded the narrow hydrophilic pore due to a higher capillarity, while the reverse configuration caused the fluid to invade the wide hydrophilic pore, trapping the other phase in the narrow hydrophobic pore. The simulations showed excellent agreement with the experimental results, demonstrating the effectiveness of the proposed fabrication technique, the robustness of the experimental setup, and the reliability of the numerical model. This study provides new insights into the impact of mixed wettability on two-phase fluid flow, highlighting the importance of wettability in controlling fluid flow pathways and entrapment. The proposed fabrication technique and experimental-numerical approach have significant implications for the development of more efficient subsurface resource management technologies.