基于近似理论水驱曲线的油藏水驱体积波及系数动态计算方法

A new dynamic calculation method of volume sweep coefficient of water drive reservoir based on approximate theoretical water drive curve

水驱体积波及系数是油藏开发过程中的重要参数,目前其计算方法需拟合油、水相相对渗透率曲线,难以满足油水渗流规律多样的复杂油藏应用的需求。为此,基于近似理论水驱曲线和Welge方程线性表达式,通过理论推导建立了一种新型的水驱体积波及系数和驱油效率动态计算方法,可根据实际生产动态数据计算不同开发阶段的水驱体积波及系数和驱油效率,克服了现有方法对油、水相相对渗透率曲线的依赖。研究表明,新方法计算结果可靠,且能准确得到复杂类型油藏不同含水率阶段体积波及系数和驱油效率的变化规律。新方法所需数据基础简单、计算简便快捷,适应各种类型油藏,可实现水驱前缘突破后各含水率阶段的准确计算,在油田动态分析和开发效果评价等方面具有广泛的应用前景。

The water drive volume sweep coefficient is an important parameter in oilfield development.At present,its calculation method needs to fit the relative permeability curves of oil and water phases,and it is difficult to meet the application requirements of complex reservoirs with diverse oil-water percolation laws.To solve this problem,based on the approximate theoretical water drive curve and the Welge linear equation,a new dynamic calculation method of displacement efficiency and volume sweep coefficient of water drive reservoir is established through theoretical derivation.The volume sweep coefficient and displacement efficiency in different development stages can be calculated based on actual production data,which overcomes the dependence of existing methods on the relative permeability curves of oil and water phases.The results show that the new method is reliable,and can accurately obtain the variation rules of displacement efficiency and volume sweep coefficient in different water cut stages in complex reservoirs.The proposed method is featured with accessible date,convenient calculation,and wide adaptability to various types of reservoirs,and it can realize the accurate calculation from low water cut stage to ultra-high water cut stage,showing a broad application prospect in dynamic analysis and development effect evaluation in oilfield.