Application of magnetic nanoparticles as demulsifiers for surfactant‐enhanced oil recovery

• Published in: Journal of surfactants and detergents Vol. 26; no. 3; pp. 401 - 408
• Main Authors: Zhang, Leilei, Bai, Chutian, Zhang, Zhuqing, Wang, Xinglin, Nguyen, Thao Vy, Vavra, Eric, Puerto, Maura, Hirasaki, George J., Biswal, Sibani Lisa
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.05.2023
• Subjects: analytical chemistry and techniques; application of surfactants
• ISSN: 1097-3958; 1558-9293
• DOI: 10.1002/jsde.12658

Nonionic surfactants are increasingly being applied in oil recovery processes due to their stability and low adsorption onto mineral surfaces. However, these surfactants lead to the production of emulsified oil that is extremely stable and difficult to separate by conventional methods. This research characterizes the stability of crude oil mixed with a nonionic surfactant, L24–22, in a brine solution. When subjected to gravity separation, a middle oil‐rich and bottom water‐rich emulsion are generated for various water–oil ratios. Thermal treatments can effectively break oil‐rich emulsions, but the bottom water layer remains contaminated with micron‐sized crude oil droplets. A magnetic nanoparticle treatment is shown to demulsify the crude oil emulsions, dropping the total organic carbon (TOC) in the water layer from 1470 to 30 ppm.