A review on the mechanisms of low salinity water/surfactant/nanoparticles and the potential synergistic application for c-EOR

Chemical enhanced oil recovery (c-EOR) is a conventional and promising strategy to recover oil from reservoir techniques such as low salinity water flooding (LSWF), surfactant flooding, alkaline flooding, polymers flooding, and nanofluid flooding. The use of various types of chemical materials for c-EOR method has recently attracted the attention of the oil and gas industry. The primary objective of this review work is to explore the synergy of low salinity water/surfactant/nanoparticle flooding for effective c-EOR method and investigate the mechanism behind these methods. The advantages of combining these chemical materials for c-EOR methods is also reviewed. Challenges and limitations of this synergy and their economic feasibility for additional oil recovery and potential return on investment are reviewed. Nanoparticles have been successfully used in various applications in several industries and have also shown good application for EOR in terms of wettability alteration. LSWF contributes to wettability alteration, while surfactant contributes to wettability alteration and interfacial tension (IFT) reduction. However, fines migration caused by LSWF and nanoparticle agglomeration can cause formation damage, while excessive surfactant adsorption can lead to cost overrun on surfactant use. Understanding the characteristics of reservoir formation mineralogy and appropriate nanoparticle type, size, and concentration can be used to resolve this challenges. The synergy of LSWF and nanoparticles in alkaline medium can serve as sacrificial agent to reduce excessive surfactant loss. Therefore, the appropriate synergistic formulation of LSFW/surfactant/nanoparticle can improve additional oil recovery and support return on investment for c-EOR projects.