Experimental Study of Non-Newtonian Behavior of Foam Flow in Highly Permeable Porous Media

Abstract

Foam-flow behavior in highly permeable porous media is still unclear. Two types of pregenerated foam using porous columns filled with fine sand and 1 mm glass beads were studied in different packs of glass beads with monodisperse bead size. Foam generated in fine sand had a sharp displacing front. However, the foam pregenerated using 1 mm glass beads had a transition zone front. We found that the transition foam-quality regime was independent of the porous medium grain size only when the bubbles are smaller than the pores. The apparent viscosity of foam was found to follow the Herschel−Bulkley model if the foam bubble sizes were smaller than the pore sizes. When the bubbles were of the same size as the pores, the foam behaved like a Newtonian fluid at low flow rates and, by increasing flow rates, exhibited shear-thinning fluid behavior. Furthermore, the apparent foam viscosity was found to increase with permeability.