Investigation of Dynamic Swelling and Interfacial Tension of Crude Oil/Brine in the Presence of

Summary In present study the effects of diethyl ether (DEE) on the interfacial property of the crude oil/brine system was investigated using a pendant drop method. Both IFT and the dynamic swelling factor in the presence of DEE was measured at 30, 50 and 70 °C and 2000 psi pressure. Seawater(SW) was selected as the base fluid and its different concentrations, i.e., 0.1SW and 2SW were prepared to mimic low and high salinity water. Results showed that at the SW, with adding the DEE to the aqueous solution, there is a meaningful reduction in the IFT profile was observed after 200s and it finally reached an equilibrium-IFT of 2.93 mN/m. With the increase of temperature from 50 and 70 °C, the equilibrium-IFT of 2.5 and 2.20 mN/m, were obtained. By reducing salinity to 0.1SW and adding DEE, IFT decreased with a slower rate to 6 mN/m as compared to SW and showed a longer equilibrium time. As to the salinity of 2SW, the trend of dynamic IFT was similar to the case of SW. Moreover, a larger dynamic swelling factor was observed in the presence of salt and DEE in the aqueous phase.