Polysaccharide-stabilized oil-laden foam for enhancing oil recovery

Understanding the influence of crude oil on foam stability is critical to investigations of improved foam-EOR process. With enough physical actions, the oil phase can pour into and be trapped in the aqueous network, enfolding the gas bubbles with a honeycombed structure, which forms an extraordinary ternary system also known as oil-laden foam (see Fig.1). The goal of this study is to investigate the synergistic effects of using a blend of xanthan gum (XG) and alkyl polyglycoside (APG) on the stability of oil-laden foam, and a series of experiments are developed. The results indicate that the addition of XG in the oil-laden foam can boost the performance including both emulsification and pseudoemulsion film aspects. One way is to reduce the liquid drainage or hinder the movement of oil droplets within liquid films by increasing the emulsion stability and liquid viscosity. Another is to decrease the rupture of tri-phase foam by creating the high-stable pseudoemulsion film with a dense and elastic adsorption layer. Under the synergistic effect of these two mechanisms, the dynamic stability of liquid films can be improved, bubble coarsening and gas diffusion can be hindered, and finally the stability of the oilladen foam can be greatly increased. The stable oil-laden foam (i.e., the oil-continuous films) is created during the XG/APG foam injection, which is in favor of mobility control and oil displacement.