Phase behaviour and characterization of microemulsion stabilized by a novel synthesized surfactant: Implications for enhanced oil recovery

The phase behavior of microemulsion systems comprised of methyl ester sulfonate (MES) as surfactant, propan-1-ol as cosurfactant, brine and alkane oils with varying chain lengths were studied for application in enhanced oil recovery. The aggregation and adsorption behavior of Jatropha oil-derived anionic surfactant were studied to investigate its favourability for use in microemulsion systems. Oil and water solubilisation parameters were determined in order to identify the optimal salinity values. The relative phase volumes were also studied as a salinity scan of microemulsion systems. The interfacial tension values between microemulsion and alkane systems were found to be much lower than that of surfactant and alkane systems. The prepared microemulsions were characterized by dynamic light scattering analysis and the particle sizes have been obtained in the range of 5–80 nm. Rheological studies revealed that the microemulsions exhibited non-Newtonian behaviour with favourably high viscosity values. Sandpack flooding using microemulsion systems was conducted at laboratory scale to predict the performance of microemulsion in oil recovery. It was found that the injected microemulsion formulations can achieve about 30% oil recovery close over conventional secondary water-flooding.