Xanthan gum-added natural surfactant solution of Chuback: A green and clean technique for enhanced oil recovery

Abstract

Enhanced oil recovery (EOR) is one of the most important branches of petroleum engineering. For this purpose, the surfactant flooding method remains one of the primary methods because of the prospects of wettability adjustment and a decrease in oil-water interfacial tension (IFT). However, environmental load and high costs make synthetic organic surfactants flooding inefficient and uneconomical under certain conditions. A new natural surfactant, viz. Chuback, was introduced in this study because natural surfactants are environmentally benign, nonhazardous, and cost-effective. The effects of adding bio-based xanthan gum (XG) and increasing the salinity on the wettability adjustment, IFT, rheological behaviors, and core flooding characteristics were investigated in terms of the performance of the designed surfactant-polymer flooding system. The results showed that Chuback is very efficient in wettability alteration from an oil-wet state to a water-wet state with an increase in the oil droplet contact angle in the carbonate (from 16.71° to 60.52°) and sandstone (from 8.87° to 50.1°) rock cores. In addition to the 28.6% higher oil recovery in the carbonate core, effective IFT reduction of 74%, and almost optimum mobility ratio (M = 1.01), Chuback exhibited excellent improvement in its rheological properties in the presence of XG, even under high-salinity conditions; its effect was comparable to that of commonly used synthetic surfactants. Thus, in this study, we successfully determined the application of Chuback as a suitable candidate for EOR purposes.