Effects of dissolved carbon dioxide and ions in water on the dynamic interfacial tension of water and oil in the process of carbonated smart water injection into oil reservoirs

The smart water technology means the engineering and management of injectable water containing soluble ions to enhance oil recovery. Adding dissolved carbon dioxide to this method, called carbonated smart water, can be more effective. One of the most important parameters in the development of the interfacial tension (IFT) of water and oil is normally the addition of chemical additives to injected water. The carbonated smart water, however, is more effective on the wettability alteration of the reservoir rock but it is not ineffective in reducing the interfacial tension. Therefore, the study of the functioning of this mechanism seems logical in this method. Examples of the mechanism of ions in different salts and the transfer of carbon dioxide from water to oil, and the physical and chemical reactions of ions and dissolved carbon dioxide at the joint oil and water levels affect this parameter. Therefore, the time for the contact of smart and carbonated water can be important when the parameters are dependent on time. In this study, the intercalation rates of carbonated water and oil are presented with respect to time in a range of ions from the dissolved NaCl, KCl, MgCl2, CaCl2, Na2SO4, MgSO4, KI, FeSO4, Na2CO3, K2SO4 and NaHCO3 salts in the presence of the dissolved carbon oxide at 75 degrees C and the pressure of 2000 psi using the pendant drop experiments and Axisymmetric Drop Shape Analysis (ADSA). The results show that the simultaneous presence of ions at low concentrations and dissolved carbon dioxide can be effective in reducing the interfacial tension. The reduction of interfacial tensions by carbonated smart water at constant temperature and pressure depends on the type of dissolved ions and the time faced by oil and carbonated smart water due to the greater activity of dissolved carbon dioxide mechanisms over time.