This study aims to compare different water-based chemicals that can be used for enhancing the oil recovery of shale-oil reservoirs, including surfactants, nanoparticles, and ketones. A screening criterion was adopted to select the chemicals based on their aqueous stability at high-temperature and high-salinity (HT/HS) conditions. Afterward, the surviving chemicals were further screened based on their ability of oil/water interfacial-tension (IFT) reduction and wettability alteration.
Methodology
Materials. A variety of surfactants were used in this study to identify those that remain stable under HT/HS conditions of 90°C and 255,000‑ppm salinity. A total of 40 surfactants was tested, consisting of 13 anionic, six cationic, nine zwitterionic, and 12 nonionic surfactants.
