Modeling and Upscaling of Viscous Fingering during Unstable Drainage Displacements

Abstract

Abstract Viscous fingering is a common phenomenon in viscous oil waterflooding, gas flooding and carbon sequestration processes. Wettability has been shown to have a significant effect on viscous fingering. The objective of this research is to model viscous fingering during drainage displacements, i.e., a non-wetting phase displacing a viscous wetting phase. We modified a previously proposed effective-fingering model for imbibition processes. Laboratory unstable coreflood experiments were history matched. Power-law correlations were developed between history matched model parameters and physical parameters such as the velocity and viscosity ratio. Fine-grid intermediate scale simulations were conducted with the effective-fingering model for domains with different degrees of heterogeneity. Coarse-grid simulations were run to determine the shape factor (one of the effective-fingering model parameters) needed to match the result of fine-grid simulations. The shape factor is a function of the correlation length, Dykstra-Parsons coefficient and viscosity ratio. This correlation can be used to upscale the interaction between viscous fingering and channeling in large scale simulations.