化学驱微观机理及体系优选实验研究*

通过微观仿真刻蚀模型,结合河南油田某区块的孔隙结构,在水驱基础上进行表活剂驱、聚合物驱、聚合物/表活剂二元驱。分析研究了每种驱替体系对水驱产生的盲端、膜状、吸附、簇(柱)状、孤岛状的启动机理,同时量化三种化学体系对各类剩余油在模型中的驱替效率。实验结果表明,盲端剩余油适合高黏聚合物体系,针对不同形状盲端不同界面张力的体系作用效果不同;孤岛状剩余油适合高黏体系,界面张力对其影响不大;吸附状剩余油适合聚合物体系的黏度为(10~20)m Pa·s,且降低体系界面张力有利于启动此类型残余油,但在模型中多会形成此类残余油;膜状剩余油在低黏度聚合物体系下即可以很好启动,适宜体系界面张力数量级在10-1~10-2之间;化学驱启动剩余油,后续油启动运移过程中易形成小径簇状油,其含量在剩余油中占的饱和度较大。

THE MICROSCOPIC SUTDY ON MECHANISMS AND THE OPTIMIZATION OF OIL DISPLACEMENT BY DIFFERENT CHEMICHAL ECOSYSTEMS

Through the microscopic simulation of etching model, combined with the pore structure of Henan oilfield,surfactant flooding, polymer flooding and polymer / surfactant flooding,were made basing on water flooding. The remaining oil after the water flooding are classified into five major categories, which are called the blind end, membranous, adsorption, cluster (column), shaped island.Analyze the starting mechanism of five patterns of remaining oil each displacement solution. At the same time, quantize the displacement efficiency of three kinds of chemical systems on different types of remaining oil in the model. The experimental results show that, the blind end of remaining oil is suitable for high viscosity polymer system, and different interfacial tension systems have a different effect on different shapes of blind end;isolated remaining oil is suitable for high viscosity,interfacial tension had little effect on this type of remaining oil; adsorption type is suitable for the polymer system, which of viscosity is between 10mPa.s to 20mPa.s, and reducing the interfacial tension is favorable toward starting this type of residual oil, but in the process of starting other types of remaining oil,this type will mostly be formed;residual oil film can be very fine started by low viscosity polymer system, suitable for the interfacial tension between 10-1~10-2; since the chemical flooding has started the residual oil,in the process of migration of the following oil, clusters of oil is easy to be formed in some small pores,and its content in the remaining oil accounts for the high degree of saturation.