天然裂缝性碳酸盐岩封闭油藏产量递减规律研究及应用

建立了天然裂缝性碳酸盐岩封闭油藏渗流模型。考虑了封闭油藏定井底压力和变井底压力两种不同的内边界情形,并采用Laplace变换和Duhamel原理对数学模型进行了求解,得到了天然裂缝性碳酸盐岩封闭油藏的递减曲线,在曲线上产量出现两个明显的递减阶段和两个相对平缓的递减阶段,讨论了窜流系数和裂缝弹性储容比对天然裂缝性油藏递减曲线的影响。实例表明,实际产量资料与理论递减曲线的拟合可确定地层参数,预测产量变化。

Research and application on production decline rule of closed carbonate reservoir with natural fractures

A percolation model for closed carbonate reservoir with natural fractures was built. Considering both constant and variable bottomhole pressure as the inner boundary conditions and solving its corresponding mathematical model using Laplace transform and Duhamel principle gave decline curve of the production rate in the oil reservoir, on which both two rapid declining phases and two relative gentle ones appeared. The influence of interporosity flow coefficient and elastic storage -volume ratio on the decline curve for the naturally fractured reservoir was discussed. Field example demonstrates that by matching actual production data with theoretical decline curve formation parameters can be determined and future production can be predicted.