Abstract
Displacement of viscous oils often involves unstable immiscible flow. Viscous fingering and its influence on relative permeability was studied in this work at different viscosity ratios and flow rates. Silica and glass micromodels were used to visually inspect the effect of viscosity ratios and flowrate to understand the interplay of viscous and capillary forces in the viscous dominated regime. Using the knowledge of fingering pattern at the small scale, a lumped finger model was developed for modeling multiphase flow at larger scales. The lumped finger model is incorporated with oil and water flow equations to yield pseudo-relative permeability functions. This formulation was validated against several laboratory core floods. The experimental recovery at different viscosity ratios and flow rates showed a power law dependence with a new dimensionless number, . The parameters of the lumped model also show a correlation with this dimensionless number.
