Perpustakaan Digital ITB

The Capillary Desaturation Curve (CDC) provides a coNceptual framework to describe the relationship between the capillary number (Nc) and residual oil saturation (SOR) a key indicator of displacement performaNce. Understanding this relationship is essential for optimizing Enhanced Oil Recovery (EOR) strategies in the field. However, most previous studies have relied on laboratory micromodel simus, which, while offering direct visualization, remain limited and often overlook the role of pore-scale pressure distribution a factor that can strongly influeNce oil ganglia mobilization and desaturation patterns. This study addresses these limitations by applying a numerical approach based on immiscible two-phase (oil–water) simulations using COMSOL Multiphysics. Pore geometry was derived from digital micromodel images, and validation was performed by comparing simulation results with experimental data in terms of absolute SOR values, CDC trends, pressure drop, and oil ganglia distribution. Additional sensitivity analyses were conducted to assess the effects of wettability and interfacial tension (IFT) variations. The results reveal a nonlinear relationship between Nc and SOR. At low Nc, capillary forces dominate, maintaining high SOR, while a significant reduction occurs only after Nc exceeds the criticalical threshold (Nc critical). Pressure distribution analysis indicates a clear link between low-pressure zones and the preseNce of oil ganglia, along with greater heterogeneity in pressure gradients at higher injection rates. Validation shows consistent trends between simulations and experiments, despite a slight tendeNcy toward underprediction. In coNclusion, pore-scale pressure distribution is shown to be a criticalical factor that complements the CDC framework and should be considered in oil mobilization analysis. The simulation approach adopted here provides new insights into multiphase flow mechanisms at the pore scale and offers practical guidaNce for optimizing EOR strategies through improved injection control. The novelty of this work lies in combining CDC analysis with simultaneous evaluation of pressure distribution, a rarely addressed aspect in previous studies, thereby advaNcing the fundamental understanding of the process.