Recyclable and Magnetic Fe3O4@SiO2-Surfactant Nanoparticles for Rapid Demulsification and Enhanced Oil Recovery
Yao Wang, Lutao Yang, Qingfeng Hou, Zhuoyan Zhu, Xiaoling Yi, Yuanyuan Wang, Weidong Chen, Haoran Zheng, Yifeng Liu, Jun Zhang, Weidong Liu, Bin DingAbstract
A magnetically responsive nano-agent, Fe3O4@SiO2-BS12, was developed to improve the sustainability of chemical enhanced oil recovery. The nano-agent was designed to integrate effective oil-displacement capability with easy magnetic recovery for reuse. Characterization confirmed its core−shell structure, strong magnetism, and successful surfactant loading. Performance tests showed it could reduce interfacial tension to an ultra-low level (0.01 mN/m) while enabling effective emulsion separation under a magnetic field. Core flooding experiments verified its practical efficacy. Injection of the freshly prepared nano-agent following water flooding resulted in an additional 19.7% increase in total oil recovery. Notably, the nanoparticles were magnetically recovered and reused in a subsequent flood, still providing a significant incremental recovery of 17.9%. These results demonstrate a successful balance between high performance and recyclability. Overall, Fe3O4@SiO2-BS12 represents a promising reusable nano-fluid, offering a cost-effective and sustainable strategy for enhanced oil recovery through the integration of high displacement performance and a recoverable life cycle.