Synergistic Collaboration between Regenerated Cellulose and Surfactant to Stabilize Oil/Water (O/W) Emulsions for Enhancing Oil Recovery

A stable emulsion can play an important role in displacing oil or controlling reservoir conformance for enhanced oil recovery (EOR) projects. In this work, visual inspection, multiple-light scattering, interfacial tension (IFT), and rheology were used to investigate the synergistic effects of regenerated cellulose and surfactant on oil-in-water emulsions stability and their efficiency in EOR. The results show that adding regenerated cellulose can significantly increase the stability of a surfactant emulsion, while decreasing the diameter, coalescence, and floatation of oil droplets. This can be attributed to the synergistic interactions between cellulose and surfactant, which enable them to form a tighter interface layer and slightly reduce the oil/water (O/W) IFTs. Moreover, in comparison with the surfactant-only systems, the surfactant-cellulose systems exhibit higher viscoelasticity of the continuous phase, as well as better shearing tolerance and self-recovery of emulsions. Ultimately, the microscopic oil displacement experiments demonstrate that the system can efficiently decrease the residual oil saturation after water flooding. These impressive performances make this blended system ideal for use in the chemical flooding process for EOR.