无碱二元复合驱中表面活性剂对驱油效果的影响

Effect of surfactants on oil displacement in alkali-free binary composite flooding

表面活性剂在无碱二元驱油体系中可以促使残余油启动,扩大波及体积,提高微观驱油效率。本文研究了无碱二元驱油体系中表面活性剂通过改变界面张力、毛管力和吸附浓度对驱油效果的影响。结合前期室内实验和大庆油田萨中西区一类油层试验区矿场试验数据,配合使用化学驱模拟软件ChemEOR,建立9注16采理想模型进行无碱二元复合驱数值模拟。通过改变表面活性剂浓度改变界面张力、毛管力和表面活性剂吸附浓度,分析含水率、累产油和采出程度,从而得到无碱二元驱油体系中界面张力、毛管力和表面活性剂吸附浓度对驱油效果的影响。研究结果表明,无碱二元复合体系中适宜的表面活性剂界面张力为10-3数量级,表面活性剂作用下改变毛管力对驱油效果影响不明显,表面活性剂吸附浓度为0.25wt%时驱油效果最好。

Surfactant can promote the start of residual oil in the alkali-free binary flooding system, expand the volume and increase the microscopic oil displacement efficiency. In this paper, the effect of surfactant on the oil displacement effect by changing the interfaeial tension, capillary force and surfactant adsorption concentration in the alkali-free binary flooding system was studied. Combining the pre-indoor laboratory experiments and the field test data of the first-class oil layer test area in Sazhongzhong District of Daqing Oilfield, combined with the chemi- cal flooding numerical simulation software ChemEOR, Numerical simulation of the idealized non-alkali binary oil- displacement system with 9 injection and 16 wells, the interfacial tension, capillary force and surfactant adsorption concentration were changed by changing the surfactant concentration. Finally, the analysis of water content, oil pro- duction and recovery degree can be used to obtain the effect of interracial tension, capillary force and surfactant adsorption concentration on the oil displacement effect in the alkali-free binary oil displacement system. The calcu-lated results show that the suitable surfactant interracial tension in the alkali-free binary composite system is 10^-3 orders of magnitude,The effect of changing the capillary force under the action of surfactant on the oil displacement effect is not obvious. When the concentration of surfactant is 0.25wt%, the oil displacement effect is the best.