Effect of adsorption of different types of surfactants on conglomerate reservoir minerals on chemical oil recovery efficiency

Abstract Using surfactants to extract oil, the anionic surfactant Karamay petroleum sulfonate (KPS), the zwitterionic surfactant octadecyl betaine (BS-18) and the nonionic surfactant coconut oil fatty acid diethanolamide (6501) were selected for adsorption experiments with minerals contained in the conglomerate reservoir with different mineral compositions to study the adsorption law of different types of surfactants. Zeolite and montmorillonite, which have the highest specific surface area and zeta potential among the minerals in the conglomerate reservoir, have the most obvious adsorption effect on surfactants, resulting in a large amount of adsorption of KPS and BS-18. The three types of surfactants were then used to conduct physical simulation oil recovery experiments with conglomerate core samples, and the results showed that 6501 had better overall performance, the best adsorption resistance, and a higher degree of recovery in oil recovery experiments, which provided a basis for the selection of surfactants in the process of chemical drive in conglomerate reservoirs.