海外普通稠油油水相对渗透率曲线测试及差异解释

Testing and Interpretation of Differences in Oil-water Relative Permeability Curves for Conventional Heavy Oil Overseas

国内I-2型普通稠油注水开发效果较好的油藏原油黏度都小于300 mPa·s,而海外哈萨克斯坦科克日杰侏罗系普通稠油黏度介于300~1300 mPa·s之间,没有成功的水驱开发经验可供借鉴参考。为此,采用室内物理模拟研究手段,通过非稳态驱替方法测定了高、低两种黏度油水相对渗透率曲线。结果表明:高黏度原油的油水相渗曲线特征为,油相曲线陡且下降快,水相曲线上升缓慢;两相流动区间较窄,驱油效率和束缚水饱和度低于低黏度对应下的驱油效率;低黏度原油的油水相渗曲线特征为,油相曲线陡且下降快,水相曲线上升缓;两相流动区间较宽,残余油饱和度低于高黏度对应下的饱和度值。低、高黏度下油水相对渗透率差异较大的主要原因是油水黏度比存在较大差异。

In China,the viscosity of crude oil in I-2 ordinary heavy oil reservoirs with good water injection development effect is less than 300 mPa·s,while overseas,the viscosity of Jurassic ordinary heavy oil in Kazakhstan's Kokzhide field ranges from 300 mPa·s to 1300 mPa·s.Therefore,there is no successful water flooding development experience to draw on.To this end,the relative permeability curves of oil and water were determined by non-steady-state displacement method for high and low viscosity oils using physical simulation in the laboratory.The research results showed that the oil-water relative permeability curves of high viscosity crude oil were characterized by steep and fast downward slope of the oil phase curve,slow upward rise of the water phase curve,narrow flow range of the two phases,and lower oil recovery efficiency and bound water saturation than those corresponding to low viscosity.The oil-water relative permeability curves of low viscosity crude oil were characterized by a steep and rapid decline in the oil phase curve and a slow rise in the water phase curve.The flow range of the two phases was wide,and the residual oil saturation was lower than the saturation value corresponding to high viscosity.The main reason for the significant difference in oil-water relative permeability between low and high viscosity was the large difference in the oil-waterviscosityratio.