Preparation and Investigation of Temperature-Responsive SiO<sub>2</sub>–PSBMA Janus Nanosheet with Salt-Tolerant Properties for Enhanced Recovery of Heavy Oil
Jianwen Hu, Haotian Gao, Wenqing Xie, Junjie Fan, Shuai Zhang, Shuangqing Sun, Songqing Hu, Y. Zhong
Abstract
Enhancing heavy oil recovery is crucial to ensuring stable crude oil production. The development of stimulus-responsive Janus Pickering emulsifiers tailored for a reservoir environment has garnered significant attention in the field of reservoir production, emerging as a promising alternative to traditional surfactants. In this study, silica-based Janus nanosheets with temperature-responsive properties (OH-SiO 2 –PSBMA JNs) are synthesized using sol–gel process and atom transfer radical polymerization (ATRP) method. Experimental observations reveal that OH-SiO 2 –PSBMA JNs (0.1 wt %) can effectively reduce the interfacial tension (IFT) between heavy oil and water to 23.24 mN/m. Additionally, these nanosheets exhibited excellent emulsifying ability, forming stable emulsions with an average particle size of only 35 μm at a mass fraction of 1 wt % and demonstrating good salt tolerance (Salinity value: 1.51 × 10 4 mg/L). Furthermore, OH-SiO 2 –PSBMA JNs exhibited a temperature response that is well-suited for the reservoir environment, effectively stabilizing heavy oil emulsion at a high temperature (65 °C) and facilitating oil–water separation at a lower temperature (25 °C). These excellent properties of nanosheets contributed to obtaining an additional 13.2% recovery rate at low concentration (0.03 wt %). These results indicated that OH-SiO 2 –PSBMA JNs had the potential for enhanced oil recovery (EOR) application.