Performance Evaluation of the Green Surfactant-Treated Nanofluid in Enhanced Oil Recovery: Dill-Hop Extracts and SiO2/Bentonite Nanocomposites

This study focuses on developing a surfactant-treated nanofluid (nanosurfactant), a green and sustainable solution, for improving oil recovery from carbonate reservoirs. The natural surfactants used in this study were derived from dill and hop plants, and SiO2/bentonite nanocomposites (NCs) were greenly synthesized from Commelina diffusa leaves. Different enhanced oil recovery (EOR) solutions, including dill and hop surfactants, nanofluids, and nanosurfactants, were prepared at different concentrations and subjected to several experimental tests for performance evaluation and characteristic analyses. The obtained results show that the critical micelle concentrations of the dill and hop surfactants were 4000 and 2000 ppm, respectively, depending on the conductivity and interfacial tension (IFT). A minimum IFT and contact angle of 1.73 mN/m and 38.5–40° were obtained under the effect of dill surfactant with 10,000 ppm NaCL and nanosurfactants at 500 ppm NCs, respectively. In addition, the dill-nanofluid solution prepared from mixing 500 ppm of NCs within 4000 ppm of dill extract enabled extraction of an additional 14.1% original oil in place from the carbonate core plug that has a porosity of 26.47% and permeability of 2.94 mD. These improvements in the EOR parameters confirm the stability and efficiency of the formulated green solution as an active EOR solution that can extract a high amount of crude oil in an ecofriendly sustainable way.