Modelization Of Surfactant Flooding: Methodology For Determining The Interfacial Tension Function Of Surfactant Concentration And Salinity

To predict accurately the amount of oil that can be recovered by a process of surfactant flood injection, a fine modelization of variation of interfacial tension between oil phase and aqueous phase with the reservoir conditions is required. Unfortunately, data of interfacial tension variation with all the parameters, i.e. temperature, salinity and surfactant concentration, are not always available when numerical simulation of the reservoir production is performed. In that case, interpolation is often used, but then cannot be fully representative of the variations. The work presented here details a new numerical model used to describe interfacial tension with all the parameters listed below. This model fit well experimental data obtained for this study. The asymmetry of the model allows to take into account the specificity of industrial formulations, when the interfacial tension at large salinities is different from interfacial tension at zero salinity. The protocol to determine experimental data of optimal salinity and interfacial tensions for such industrial formulations is detailed. The correlation described in this paper is also used to perform numerical experiments of injection of a formulation containing surfactant in porous media to recover oil. The 1D experiments are constructed using realistic parameters from literature. Sensitivity to optimal salinity is described using the interfacial tension model developed here, as well as its impact on oil production.