Effect of Gas Type and Composition on Foam Rheology in Porous Media for Enhanced Oil Recovery

We present an experimental investigation on the effect of gas type and composition on foam rheology in porous media. Our study compared steady state foam strengths with respect to three distinct gases as well two cases containing their binary mixtures. Three hypotheses with different predictions are discussed in detail to search for the underlying mechanism that explains the gas type and composition effect. We examine the stability of lamellae, effect of gas solubility and the gas diffusion rate across the lamellae respectively. It is found that steady state foam strength is inversely correlated with gas permeability across a liquid lamella, a parameter that characterizes the rate of mass transport. Our experimental results are also in good agreement with existing observations that a mixture of gases usually has approximately the same foam strength as that of less soluble gases.