Ehsan Jafarbeigi
A significant research gap in heavy oil recovery is the lack of a multifunctional agent capable of simultaneously mitigating asphaltene-related formation damage while maximizing recovery mechanisms. This study addresses this challenge by synthesizing and evaluating a Titanium dioxide/Silica nanocomposite, surface-modified with Tween 20 and synergistically integrated within a engineered low-salinity water system. The nanofluid was developed via a systematic sol-gel and impregnation method, utilizing a specific 20:80 wt% ratio of titania to silica, further functionalized with Tween 20 and Carboxymethyl Cellulose (CMC) to ensure superior dispersibility. Stability assessments revealed that at an optimum concentration of 50 ppm, the nanofluid exhibits exceptional colloidal stability with a zeta potential of −62.52 mV and a consistent particle size of ~100 nm over 25 days at 80 °C. The EOR performance demonstrated significant results: the interfacial tension (IFT) was reduced from 19.23 to 0.93 mN/m, and the contact angle of oil-aged carbonate rock shifted dramatically from a strongly oil-wet state (153°) to a strongly water-wet condition (17°). These changes are attributed to the synergistic effect of structural disjoining pressure and ionic exchange. Furthermore, FTIR analysis confirmed the highly efficient adsorption of asphaltenes onto the nanocomposite surface, where transition metal sites facilitated the strong adsorption and possible molecular interaction with asphaltene functional groups, effectively inhibiting aggregation. The findings showed that the nanofluid was responsible for recovering 36% of the oil trapped in the core. This study introduces a high-performance, cost-effective, and low-concentration solution that bridges the gap between asphaltene inhibition and advanced chemical EOR.