二元复合驱油体系乳状液形成及运移规律研究

Research on the Emulsion Formation and Migration of Polymer/Surfactant Complex Flooding System

栾和鑫 阙庭丽 云庆庆 关丹 帕提古丽·麦麦提 唐文洁 焦秋菊 向湘兴 焦秋菊 向湘兴

LUAN Huoxing QUE Tingli YUN Qingqing GUAN Dan PATIGULI· Maimaiti TANG Wenjie JIAO Qiuju XIANG Xiangxing

为了研究二元复合驱油体系乳化与提高采收率的关系，通过分析现场采出液流变特征，测试不同乳化强度 的表面活性剂/聚合物二元复合驱油体系的驱油效率，明确驱替后乳状液运移规律以及乳化对提高采收率贡 献。研究结果表明：低黏度乳状液在低剪切速率下主要表现为弹性，在较高剪切速率下主要表现为黏性；而高黏 度乳状液在低剪切和高剪切速率下都表现出黏性。在乳化初期，由于化学剂浓度分布不均匀，乳化稳定性较差； 乳化中期化学剂浓度较高，乳状液粒径变化规律性较好，乳化中期存在乳化对驱油体系黏度补偿作用，乳化末期 化学剂浓度较低，乳化液滴较少，乳化程度较弱。岩心渗透率小于100×10-3 μm2时，二元复合驱过程中随着乳化 综合指数增加，提高采收率幅度先增加后降低，最佳乳化综合指数为55%；渗透率大于100×10-3μm2时，随着乳化 综合指数增加，提高采收率幅度逐渐增加，最佳乳化综合指数为88%，乳化贡献提高采收率幅度8个百分点。

In order to study the relationship between emulsification and enhanced oil recovery（EOR）of surfactant/polymer complex flooding system with different emulsion，the emulsion characteristics of on-site production fluids of Xinjiang oilfield was analyzed，and the displacement efficiency of the surfactant/polymer complex flooding system was tested，and the migration rule of the emulsion and the contribution of emulsification to enhanced oil recovery were determined. The results showed that the low viscosity emulsion exhibited elasticity at low shear rate，and viscosity at high shear rate. The high viscosity emulsion mainly exhibited viscosity at low and high shear rate. The flooding results showed that the emulsion stability was poor at the early stage of emulsification. At the middle stage of emulsification，the concentration of the chemical agent was higher and the particle size of the emulsion changed well，hence，there existed a compensation of emulsification on the viscosity of oil flooding system. At the end of emulsification，the concentration of chemical agent was lower，the emulsion drop was less，and the degree of emulsification was weaker. When the core permeability was less than 100×10-3 μm2，the enhanced oil recovery increased first and then decreased with the increased of the emulsification comprehensive index（ECI），and the optimum ECI was 55%. When the core permeability was more than 100×10-3 μm2，with the increase of ECI，the enhanced oil recovery increased gradually，and the optimum ECI was 88%， and the contribution of emulsification to enhanced oil recovery was 8 percentage points.

10.19346/j.cnki.1000-4092.2021.02.023