Impact of pertinent parameters on foam behavior in the entrance region of porous media: mathematical modeling

Abstract

This study presents a numerical investigation of foam behavior in the entrance region of a porous medium using a fractional flow method. The model examines both cases—with and without capillary pressure—and evaluates two injection gases (N₂ and CO₂). It quantifies how key parameters (water fractional flow, residual gas saturation, foam kinetic constant, gas viscosity) influence the length of the entrance region necessary for foam texture to reach local equilibrium. Results show that entrance region length increases with reduced residual gas saturation, decreases with higher foam constant, and that CO₂ is a more effective foam-forming gas than N₂. Inclusion of capillary pressure considerably shortens the entrance region due to additional foam generation mechanisms (e.g., snap-off, leave-behind). The model improves understanding of foam-driven mobility control in enhanced oil recovery applications.,