Red beet plant as a novel source of natural surfactant combined with ‘Smart Water’ for EOR purposes in carbonate reservoirs

Abstract

The use of natural green surfactants has become one of the most popular techniques for enhanced oil recovery (EOR) because these types of surfactants are environmentally-friendly, efficient, sustainable, and less expensive than commercial surfactants. In the current study, the extraction of natural surfactant from the Red Beet (RB) plant is introduced for EOR applications in carbonate reservoirs. Characterization analyses using TGA, FT-IR, 1H NMR, and FESEM were carried out to assess the nature of the extracted saponin as the surfactant agent. The physicochemical characterization points to a nonionic surfactant. The role of salinity, with varying NaCl concentrations, in ‘smart water’ flooding using the RB surfactant was then investigated. According to the measured interfacial tension (IFT), the critical micelle concentration (CMC) of the extracted surfactant from the RB plant was 2500 ppm, and the IFT value at the CMC point was 9.92mN/m for deionized water. The parametric flooding study revealed that the RB surfactant injection as the source of the green surfactant (at its CMC value with 15,000 ppm NaCl as the optimum salinity) contributed, as the tertiary recovery, to an extra 26.29 % of the original oil in place (OOIP) because of a considerable decrease in contact angle from 151.4° to 42.14° and a decline in IFT values from 33.87 to 9.27 mN/m.