Laboratory Investigation of Hybrid Nanoparticles Injection for Enhanced Oil Recovery Process

Nanoparticles due to their unique characteristics are gaining attraction for enhanced oil recovery (EOR) applications. Nanoparticles during the EOR process may activate many mechanisms, particularly wettability alteration, and thus improve the recovery factor. Silica nanoparticle has been largely testified for EOR. The effect of alumina nanoparticles for EOR is also being investigated recently. Their combination may enhance their performance in wettability alteration. In this research, we studied the wettability alteration and recovery performance of the hybrid nanoparticles. A series of experiments were conducted starting from zeta potential and contact angle measurement to determine optimum concentrations of silica, alumina, and hybrid nanoparticles. After dispersing nanoparticles (alone and hybrid), solutions were homogenized using ultrasonic homogenizer. The zeta potential results showed that the silica nanofluid could stay stable for at least 3 days without the need for a stabilizer. However, a stabilizer (SDBS) is required to prepare stable alumina and hybrid nanofluid. Baseline experiments were conducted with the stabilizer to quantify the performance of the stabilizer. Later, contact angles were measured (at room temperature and 80 °C) to analyze the effect of the nanofluid on rock/oil/brine systems and to determine the optimal nanofluid concentration. The results of contact angle experiments prove that, for both temperatures (room and 80 °C), maximum alteration in wettability was shown by the hybrid nanoparticle mixture (0.1wt%silica+0.05wt%Alumina), 29° and 33°, respectively. Finally, coreflooding tests were conducted to study the performance of the optimal nanofluid in enhancing oil r ecovery. The coreflood experiment was conducted with optimum hybrid nanofluid at 80 °C. The recovery factor recorded with Caspian Seawater was 42%, and silica nanofluid improved the recovery to 46%. The injection was followed by a hybrid nanofluid, which increased the recovery factor to 73%. The results presented in this study prove that hybrid nanoparticle injection improves the performance as compared to standalone nanoparticles.