Effect of chemicals on the phase and viscosity behavior of water in oil emulsions

Masoud Shafiei; Yousef Kazemzadeh; Dmitriy A Martyushev; Zhenxue Dai; Masoud Riazi

doi:10.1038/s41598-023-31379-0

Effect of chemicals on the phase and viscosity behavior of water in oil emulsions

Sci Rep. 2023 Mar 12;13(1):4100. doi: 10.1038/s41598-023-31379-0.

Authors

Masoud Shafiei¹, Yousef Kazemzadeh^{2

3}, Dmitriy A Martyushev⁴, Zhenxue Dai⁵, Masoud Riazi⁶

Affiliations

¹ Enhanced Oil Recovery Research Center, School of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Iran.
² Enhanced Oil Recovery Research Center, School of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Iran. yusefkazemzade@yahoo.com.
³ Department of Petroleum Engineering, Faculty of Petroleum, Gas, and Petrochemical Engineering, Persian Gulf University, Bushehr, Iran. yusefkazemzade@yahoo.com.
⁴ Department of Oil and Gas Technologies, Perm National Research Polytechnic University, Perm, 614990, Russia.
⁵ College of Construction Engineering, Jilin University, Changchun, China.
⁶ Enhanced Oil Recovery Research Center, School of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Iran. mriazi@shirazu.ac.ir.

Abstract

Due to population growth, the need for energy, especially fossil fuels, is increased every year. Since the costs of exploring new reservoirs and drilling new wells are very high, most reservoirs have passed their first and second periods of life, and it is necessary to use EOR methods. Water-based enhanced oil recovery (EOR) methods are one of the popular methods in this field. In this method, due to the possibility of emulsion formation is high, and by creating a stable emulsion, viscosity and mobility improved. In this study, the parameters affecting the stability and viscosity of the emulsion have been investigated step by step. In the first step, 50% (v/v) of water has been selected as the best water cut. The type of salt and its best concentration was evaluated in the second step by measuring the average droplets size. The third step investigated the effect of SiO₂ nanoparticles and surfactant (span80) on emulsion stability and viscosity. According to the results, the best amount of water cut was 50% due to the maximum viscosity. In salts the yield was as follows: MgCl₂ > CaCl₂ > MgSO₄ > Na₂SO₄ > NaCl. The best yield was related to MgCl₂ at a concentration of 10,000 ppm. Finally, it was shown that the synergy of nanoparticles and surfactants resulted in higher stability and viscosity than in the case where each was used alone. It should be noted that the optimal concentration of nanoparticles is equal to 0.1% (w/w), and the optimal concentration of surfactant is equal to 200 ppm. In general, a stable state was obtained in 50% water-cut with MgCl₂ salt at a concentration of 10,000 ppm and in the presence of SiO₂ nanoparticles at a concentration of 0.1% and span 80 surfactants at a concentration of 200 ppm. The results obtained from this study provide important insights for optimal selection of the water-based EOR operation parameters. Viscosity showed a similar trend with stability and droplet size. As the average particle size decreased (or stability increased), the emulsion viscosity increased.