Mechanisms of nanofluid based modification MoS₂ nanosheet for enhanced oil recovery in terms of interfacial tension, wettability alteration and emulsion stability

Abstract

Recently, much attention has been directed toward nanofluids’ applications for enhanced oil recovery (EOR). Here, amphiphilic molybdenum disulfide (KH550-MoS₂) nanosheets are synthesized using a hydrothermal approach. The physicochemical properties and EOR potential of ultralow concentration KH550-MoS₂ nanofluids are systematically investigated at Changqing Oilfield (China) reservoir conditions (temperature∼55 °C and salinity∼7.8 × 10⁴ mg/L). Interfacial tension (IFT), wettability alteration and emulsion stability are characterized to evaluate the physicochemical properties of KH550-MoS₂ nanofluids. The results show that ultralow concentration KH550-MoS₂ nanofluid (50 mg/L) can decrease IFT to 2.6 mN/m, change contact angle (CTA) from 131.2° to 51.7° and significantly enhance emulsion stability. Core flooding experiments are conducted to determine the dynamic adsorption loss law and oil displacement efficiency of KH550-MoS₂ nanofluid. Results indicate that the cumulative produced KH550-MoS₂ nanosheets ratio to total injected KH550-MoS₂ nanosheets (CNR) reaches 91.5% during flooding in a low permeability reservoir. Moreover, ultralow concentration KH550-MoS₂ nanofluid can increase oil displacement efficiency by 14% after water driven. This work offers a new amphiphilic nanofluid with high efficiency for EOR.

Graphical Abstract

Keywords:

• Amphiphilic molybdenum disulfide nanosheets
• Nanofluid
• Interfacial property
• Core flooding experiment
• EOR

Acknowledgments

Tuo Liang wants to thank the invaluable care and support from his wife Jiaxin Xi over the years. You are the world to me.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors gratefully appreciate the financial support of the Science Foundation of China University of Petroleum, Beijing (No.2462020XKBH013). Financial supports from the National Natural Science Foundation of China (Grant No. 51804316) and the Science Foundation of China University of Petroleum, Beijing (Grant No. 2462017YJRC037) are also greatly acknowledged.