为阐明高频/高压脉冲交流电场中化学破乳剂、温度及聚合物对油包水型乳化液中分散相液滴变形与聚并行为的影响规律,本工作采用显微高速摄像技术系统分析了不同因素对液滴运动的作用机制。结果表明,仅电场作用时,液滴变形度随场强增加而增大,破碎临界场强为5.0 kV/cm;双液滴聚并的最优电场参数为电场强度3.0 kV/cm、电场频率2.5 kHz。升温可促进液滴变形,降低其破碎临界场强,并缩短两液滴接触时间,但温度过高不利于液滴聚并。电场与破乳剂协同作用时,最优破乳剂浓度为100 mg/L,在3.0 kV/cm下两液滴接触时间最短为6 ms。聚合物的存在会抑制液滴变形并提高聚并所需场强,通过加入破乳剂和升温则可有效促进聚并,提升破乳效率。本研究结果可为聚合物驱采出液处理用高效破乳脱水设备操作参数的选取提供参考和指导。
To clarify the effects of chemical demulsifiers, temperature, and polymers on the deformation and coalescence behaviors of dispersed droplets in water-in-oil emulsions under high-frequency/high-voltage pulsed alternating current (AC) electric field, microscopic high-speed photography was employed to systematically analyze the mechanisms of droplet movement influenced by different factors. The results showed that under the electric field alone, the degree of droplet deformation increased with the increase of electric field strength, and the critical electric field strength for droplet breakup was 5.0 kV/cm; the optimal electric field parameters for the coalescence of two droplets were 3.0 kV/cm and 2.5 kHz. Increasing temperature could enhance droplet deformation, reduce its critical electric field strength for breakup, and shorten the contact time between the two droplets. However, excessively high temperature was not conducive to droplet coalescence. When the electric field was used synergistically with a demulsifier, there was an optimal demulsifier concentration of 100 mg/L. The shortest contact time between the two droplets was 6 ms when the electric field strength was 3.0 kV/cm. The presence of polymer would inhibited droplet deformation and increased the electric field strength required for coalescence. However, the addition of a demulsifier and an increase in temperature could effectively promote coalescence and improve demulsification efficiency. The findings of this study can provide theoretical support and practical guidance for determining operating parameters of high-efficiency demulsification and dehydration equipment for the treatment of polymer flooding production fluid.