Stability phase behaviour evaluation in chemical EOR

This work presents a laboratory phase behavior study in a Sodium Stearate/ brine/ oil system. Phase behavior observations of the micro emulsion are reported both quantitative and qualitative. The experiments were designed to investigate the emulsion stability, oil/ water interfacial tension (IFT) and the viscosity of the emulsion phase in a wide range of temperature (25-60o C), water-to-oil ratio (0.2 to 5.0), salinity (10 to 200,000 ppm), and surfactant concentration. The range of variables was selected as what typically occurs during a chemical enhanced oil recovery (EOR) process. PH variations were examined by changing that of the system from 1 to 11, using different acid and alkaline. As the pH increases, the stability of the emulsion phase increases as well as the emulsion phase thickness. Besides, the viscosity of the emulsion phase was also monitored qualitatively at different temperatures. Moreover, using long chain alkanes as the oil phase, confirms the capability of the surfactant for chemical EOR process.