Nano-surfactant flooding in carbonate reservoirs: A mechanistic study

Abstract

Increasing in world oil demands versus declining world oil production highlights the importance of the enhanced oil recovery (EOR) process in oil reservoirs. So, available natural, low-cost surfactants give an opportunity to recover remaining oil via wettability alteration and lowering the interfacial tension between oil and water in the subset of a chemical process. This research presents the application of a combination of hydrophilic nano-silica and extracted surfactant from the leaves of Ziziphus spina-christi, for EOR and reservoir stimulation schemes. The core displacement experiments have been done on the carbonate core samples that had got injected with the combination of surfactant above and four different concentrations of nano silica. Results gained from this study demonstrate that with increasing concentration of hydrophilic nano-silica in the surfactant solution, surfactant concentration in the solution is 8wt%, ultimate oil recovery increases from 81.08% to 83.45% OOIP. This increment is due to increasing the viscosity of the injection fluid and reduction in the mobility ratio between oil and injection fluid. This work can draw a better understanding of an appropriate selection of chemical agents in the design of EOR schemes in carbonate reservoirs.