Investigation of Interfacial Properties for Brine/Oil Systems Containing Sulfate, Carbonate, and Nitrate Anions

• Published in: Energy & fuels 2025-01, Vol.39 (2), p.1052-1059
• Main Authors: Gonçalves, Manuela M. S., Santos, Denisson, Serpa, Fabiane S., Franceschi, Elton, Dariva, Cláudio, Borges, Gustavo R.
• Format: Article
• Language: English
• Subjects: Traditional Fossil Fuels
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.4c04801

Advanced oil recovery technologies, such as low-salinity water injection (LSWI), require a detailed understanding of oil–water interfacial properties. This study investigated the effects of sulfate (SO4 2–), carbonate (CO3 2–), and nitrate (NO3 –) anions in the presence of the strontium cation (Sr2+) on interfacial tension (IFT) and viscoelastic properties of interfacial films. The interfacial tension was assessed over 4 h using pendant drop tensiometry and then conducted a viscoelastic analysis after 20 h in solutions with different ionic strengths at 25 °C. The results showed that the sulfate ion reduced the IFT better than the other ions. It also helped make a viscoelastic interface, as shown by the increase in elastic and viscous moduli. More elastic interfaces play a crucial role in oil recovery by preventing oil from breaking up into small droplets, thus ensuring a continuous interface capable of improving the sweeping efficiency of a reservoir. Also, the viscoelastic behavior was best at an ionic strength of 1.2 × 10–3 M. This shows how important it is to get the ionic conditions just right for the best interfacial performance. This research gives us basic information about how viscoelasticity works in brine/oil systems. It can then be used to improve LSWI formulations and investigate more complex practical uses, like using produced water or seawater with varying sulfate concentrations.