Highly viscous liquid foam for oil-displacement: Surface & phase behavior enhancement

Abstract

To ensure a sustainable and efficient future, the foam flooding project has been paid more and more attentions to eco-friendly and high stability. Toward this effort, polysaccharides (XG) was applied together with alkyl polyglucoside (APG) to produce a highly stable foam. The properties in both surface and liquid phase were first studied in XG/APG solutions, and the specific characteristics created by XG/APG were then investigated from the aspects of bulk foam stability, coarsening behavior and foam viscoelasticity, after which the microstructure of foam films and the possible intermolecular interactions were inquired. The results indicated that the addition of XG in APG foam can enhance the performance includes both surface elasticity and liquid viscosity aspects, thus producing the high water-carried foam films and the super-low bubble coarsening as a result of the formation of complex aggregations by the hydrogen bonding. It was found that the foam half-life increases dramatically to 60min and the liquid drainage rate is reduced by 90% by adding only 0.1 wt% of XG. Furthermore, XG could successfully stabilize the foam front and substantially promote oil-displacement efficiency by producing a considerable capillary number and viscosity ratio in oil-bearing porous media during the foam flooding, which shows a great potential application in the oil recovery project.