Low-Shear Emulsifying System for Cold Production of Conventional Heavy Oil

作者：Fumin Zhang, Yefei Wang, Jianbin Liu, Zhengyao Dou, Jian Liao, Mifa Chen, Wuhua Chen · 发表于：Energy & Fuels · 年份：2026 · DOI：10.1021/acs.energyfuels.5c06092 · 研究领域：Enhanced Oil Recovery Techniques、Fluid Dynamics and Mixing、Pickering emulsions and particle stabilization

Emulsification-based viscosity reduction technology is an effective cold recovery method for enhancing the recovery of conventional heavy oil. However, most conventional emulsifying viscosity reducers form oil-in-water (O/W) emulsions under high-shear conditions. In contrast, the shear rate between fluid and heavy oil in actual reservoir conditions is relatively low (<10 s –1 ), which may impair the emulsification and viscosity reduction efficiency. To address this challenge, an emulsifying system (CLVR) suitable for low-shear conditions was developed to enhance the mobility and recovery of conventional heavy oil. The CLVR system comprises an anionic surfactant, sodium oleate, and a nonionic surfactant, lauric diethanolamide (LDEA). The emulsification performance, interfacial tension, viscosity reduction efficiency, and emulsion stability of the CLVR system under low-shear conditions were systematically investigated. Emulsification experiments were conducted using a thermostatic shaker at 10 rpm (shear rate of 0.42 s –1 ) to simulate low-shear reservoir conditions. The results revealed that under the optimal formulation─a total surfactant concentration of 0.25 wt % with a sodium oleate-to-LDEA mass ratio of 8:2─the CLVR system achieved an ultralow interfacial tension of 3.1 × 10 –3 mN/m and a viscosity reduction rate of 94% under low-shear conditions. Furthermore, a composite emulsifying system was developed by integrating CLVR with hydrolyzed polyacrylamide (HPAM), which con...