聚合物/表面活性剂复合体系在稠油油藏孔隙中的微观驱油过程

Micro-displacement Process of Surfactant/Polymer System in Heavy Oil Reservoir Pores

王彦玲 王刚霄 李永飞 李 强 张 悦

WANG Yanling，WANG Gangxiao，LI Yongfei，LI Qiang，ZHANG Yue

为了定性研究聚合物/表面活性剂复合体系对稠油的驱替效果，用显微镜观察复配体系在均质微观玻璃模型中的驱油过程，通过图像处理技术分析图像中的残余油分布情况、计算采收率，分析了复合体系的微观驱油机理，并与表面活性剂、聚合物和水驱驱油进行了对比。结果表明，水驱采收率最终可达 56.94%，残余油主要存在形式为柱状、油滴状、膜状、盲端油、簇状等；表面活性剂驱残余油主要以盲端残余油、簇状残余油的形式存在于孔隙中，1%阴离子型表面活性剂（BCJ-11）驱后采收率增幅为 29.46%；聚合物驱残余油主要以油丝、油膜的形式存在，注入 100 PV 1500 mg/L部分水解聚丙烯酰胺（C6725）后的采收率增幅为 22.12%复合驱残余油的存在形式为油膜，1500 mg/L C6725和 0.8% BCJ-11组成的复配体系驱替后的采收率增幅为 34.59%。对束缚在孔隙中的几类残余油，聚合物/表面活性剂驱油体系具有的黏弹性和低界面张力可以使油相界面形成细丝状不断运移。复合驱油体系驱替残余油波及范围大，波及区域的洗油效率高。图 13表2参 12

In order to qualitatively study the displacement effect of polymer/surfactant composite system on heavy oil，the oil displacement process of the composite system in homogeneous microscopic glass model was observed by microscope，and the residual oil distribution in the image was analyzed by image processing technology. The recovery rate was calculated and the microscopic oil displacement mechanism of the composite system was analyzed and compared with that of surfactant，polymer and water flooding. The results showed that the recovery rate of water flooding could reach 56.94%，and the residual oil mainly existed in the form of column，oil droplet，membrane，blind end oil and cluster，etc. The residual oil of surfactant flooding was existed in the form of blind end and cluster，and the enhanced oil recovery rate of 1% anionic surfactant（BCJ-11）flooding was 29.46%. The residual oil of polymer flooding was mainly existed in the form of filament and oil film. The enhanced oil recovery rate of 100 PV 1500 mg/L partially hydrolyzed polyacrylamide（C6725）was 22.12%. The residual oil of composite flooding existed in the form of oil film. The enhanced oil recovery rate of composite system consisting of 1500 mg/L C6725 and 0.8% BCJ-11 was 34.59%. For several types of residual oils bound in the pores，the viscoelasticity and low interfacial tension of polymer/surfactant flooding system could cause the oil phase interface to form filaments for continuous migration. The composite flooding system displaced the residual oil in a wide range，and the washing efficiency of the affected area was high.