考虑储层参数时变的相对渗透率曲线计算方法

Method for Calculating the Relative Permeability Curve of an Oil Reservoir Considering the Time-varying Effect of Relevant Reservoir Parameters

针对目前水驱油藏相对渗透率曲线计算方法未能考虑储层参数时变的问题,开展了理论研究。基于新型的近似理论水驱曲线,推导建立了油相指数、水相指数、残余油饱和度下的水相相对渗透率等相对渗透率曲线关键参数的数学表征公式,同时结合残余油饱和度计算方法,构建了一种广泛适用的考虑储层参数时变效应的油水相对渗透率曲线动态计算方法,可直接根据生产数据计算长期水驱后的油藏相对渗透率曲线。应用实例表明,新方法求得油水相对渗透率曲线可有效反映油藏动态规律,为油田可采储量标定、剩余油分布规律研究、特高含水期油藏数值模拟历史拟合等提供了理论支持。

The current method used to calculate the relative permeability curve for a water-flooded oilfield fails to consider changes to reservoir parameters over time.To resolve this problem,a theoretical study was conducted.Based on a newly developed approximated theoretical water-flooding curve,we derived mathematical formulas for the key parameters associated with the relative permeability curve.These include the oil phase index,water phase index,and residual oil saturation quantity.Combining these formulas with the method used to calculate the residual oil saturation quantity,we developed a widely applicable method for calculating the dynamic curve of oil-water relative permeability that considers the time-varying effect of relevant reservoir parameters.Based on production data,this method can be used for a reservoir after prolonged water flooding.An application example shows that the oil-water relative permeability curve derived from the new method can reflect the dynamic characteristics of the reservoir effectively.The proposed method provides theoretical support for calibrating the recoverable reserves of an oilfield and for studying the distribution of residual oil.It can also be used in numerical simulations of ultra-high water content oil reservoirs or in analytical fitting of historical data.