Abstract: In order to improve the development effect of the weak alkaline compound system in the three oil layers of Daqing Oilfield, it is necessary to optimize the formulation of compound system. Based on the combination of CMG numerical simulation and physical experiments, the effects of different concentration of formulation on the interfacial tension, emulsification performance and viscoelasticity of the system were compared and analyzed. The optimum concentration of the formulation was determined. The mechanism of the experimental results and the applicability of the system were also analyzed. The research indicates that the system can achieve ultra⁃low interfacial tension when the concentration of CHSB is between 0.2% and 0.3%, and the water absorption of the system remains below 40% when the concentration of CHSB is 0.3%, which indicates that the system has good emulsifying performance. The measured interfacial shear viscoelasticity is best when the Na2CO3 concentration is 1.2%. The results of the flooding experiment are mutually verified with the numerical simulation results. Based on development effectiveness and economic evaluation, the weak⁃alkaline ASP flooding system with the concentration of polymer HPAM is 1 000 mg/L, surfactant concentration of CHSB is 0.3%, and alkali concentration is 1.0%,which can increase the recovery rate by 23.31%. The results of this study have a guiding role in the application of weak⁃alkaline ASP flooding in the three oil layers.

Key words: Weak?alkaline ASP flooding system, Three types of oil layers, Viscoelasticity, Numerical simulation, Oil recovery

摘要： 为进一步提高弱碱三元复合体系在大庆油田三类油层中的开发效果，需要对该体系的配方进行优选。采用CMG数值模拟与物理实验相结合的方法进行研究，在室内实验的基础上，对比分析了不同配方浓度对体系界面张力、乳化性能以及黏弹性的影响，确定了该体系配方的最优浓度，并进行了实验结果的机理分析与体系的适用性评价。结果表明，表面活性剂CHSB的质量分数在0.2%~0.3%时，所研究的弱碱三元复合驱体系能够实现超低界面张力，且在CHSB质量分数为0.3%时，体系的吸水率保持在40%以下，说明其具有良好的乳化性能；Na2CO3的质量分数为1.2%时测得的界面剪切黏弹性均为最佳。驱油实验的结果与数模结果互为验证，基于开发效果与经济评价，得到HPAM的质量浓度为2 000 mg/L，CHSB、Na2CO3的质量分数分别为0.3%、1.0%时的弱碱三元复配体系，室内驱油实验表明其能够有效提高采收率23.31%。该研究成果对弱碱三元复合驱在三类油层中的应用具有重要的指导作用。

关键词: 弱碱三元复合驱, 　三类油层, 　黏弹性, 　数值模拟, 　采收率