黏度对不同渗透率稠油油藏流体渗流特征的影响

Influence of Viscosity on Fluid Percolation Characteristic in Different Permeability Heavy Oil Reservoirs

摘要: 稠油中胶质、沥青质形成的结构造成的黏度异常反映了稠油油藏的特性，对稠油的渗流特征有非常重要的影响。通过配制不同含稠油比例的油样，利用流变仪和岩心驱替装置，对不同黏度油样的流变性及其在多孔介质中的渗流特征进行了实验研究，分析了黏度对稠油渗流特征的影响。结果表明：随着油样中所含稠油比例增大，多孔介质中油样的非牛顿渗流特性增强，且渗透率越小，油样的非牛顿特性表现越明显；随着油样中稠油比例增大，水相相对渗透率迅速增大，而油相相对渗透率急剧降低，导致开采效果变差，且对流体在较低渗透率岩样中的相对渗透率影响大于高渗透率的岩样；随着被驱替油样中稠油比例增加，产出液中含水率上升的速度加快，且渗透率越低，含水率随采出程度增加的速度越快。

Abstract: The viscosity abnormality caused by the asphaltenes and resins in heavy oil reflects the characteristics of heavy oil reservoirs and has very important influence on seepage rule of heavy oil. The oil samples containing different heavy oil ratio were prepared. The rheological properties of different viscosity oil sample and its flow characteristics in porous media were experimentally studied by the rheometer and the core displacement device. The effects of viscosity to percolation characteristic of heavy oil were analyzed in detail. The results show the non-Newtonian seepage characteristic of oil samples in porous media enhances with increasing the proportion of heavy oil in the oil samples. The smaller the permeability of the porous media, the non-Newtonian behavior of oil samples is more obvious. As the heavy oil ratio increases, the relative permeability of water increases rapidly and the oil relative permeability decreases sharply which become worse at the oil recovery effect. The influence on relative permeability of fluids in the lower permeability cores is more than high permeability ones. The water cut increases rapidly in the produced fluids with increasing the proportion of heavy oil in the oil sample. The lower the permeability of the cores, the water cut with recovery percent increases more rapidly.