Experimental Study of Foam Flow in Highly Permeable Porous Media for Soil Remediation

Foam has shown promising characteristics for soil remediation, especially as a blocking agent. In very permeable porous media, high groundwater velocity reduces the efficiency of in situ remediation by decreasing the contact time with contaminants. To use foam to reduce water velocity, this paper investigates its properties in very permeable porous media (> 4.10−10 m2). Alpha olefin sulfonate foam injection experiments were conducted in columns containing glass beads or sand, with varying permeabilities and injection techniques. Pressure and mass balance data were acquired to measure foam resistance factor and liquid saturation. The results show that foam pregeneration is mandatory for generating a highly viscous foam in highly permeable porous media. However, the permeability of the foam generator does not affect the results within the range studied. Pregeneration generated highly viscous foam, even in very high permeable porous media (> 10−9 m2). The influence of permeability on the apparent viscosity of foam in porous media was related to the shear-thinning foam behavior. These experimental results show that foam injection is a relevant method for water blocking and mobility control in highly permeable porous media.