Characterization, Micellization Behavior, and Performance of a Novel Surfactant Derived from Gundelia tournefortii Plant during Chemical Enhanced Oil Recovery

Surface active agents or surfactants optimize the chemical enhanced oil recovery (EOR) operations. Since their first use, chemical surfactant applications have posed challenges because of their environmental concerns and high material expenses. The current study introduces the Gundelia tournefortii (GT) plant as a cheap and environmentally friendly source of nonionic amphiphiles for chemical EOR applications. The GT surfactant extract was evaluated using both analytical characterization tests and EOR-related experiments. Fourier transform infrared spectroscopy and thermogravimetric analysis showed the presence of amphiphile molecules in the plant extract and thermal weight loss of the novel introduced saponin-rich extract, respectively. Critical micelle concentration was characterized using various complementary tests of pH, electrical conductivity, density, turbidity, interfacial tension measurements, and micelle formation effects on properties of the solution. Foaming characterization and wettability alteration also confirmed the micellization effects. Foaming and foam half-life time parameters were also evaluated. Interfacial tension and wettability optimization by the GT surfactant solution were measured to validate its potential to enhance oil recovery, achieving a decrease in the interfacial tension from 28 to 3 mN/m and a change in the contact angle from oil-wetting to water-wetting (160 to 20 degrees). Core flooding experiments were conducted to observe and validate the efficiency of the wettability alteration and interfacial tension reduction, achieving a 19.8% increase in oil recovery compared to seawater flooding and a final oil recovery of 66.33%. Relative permeability curves of displacing and displaced fluids were computed and analyzed as wettability alteration validation and for the residual oil calculation.