低渗透油藏最小启动压力梯度实验研究

摘要

据低渗油藏渗流特点,设计"非稳态驱替-毛细管计量"与"平衡法"相结合实验测试方法,测定了新疆油田天然低渗岩心水相、束缚水下油相、两相水驱油初期最小启动压力梯度.结果表明:在油、水粘度保持不变时,油、水相及水驱油初期最小启动压力梯度与岩石气测渗透率呈幂函数关系.该测试方法能快速准确测定岩样最小启动压力,具操作简单、耗时短、数据准确、易于应用等优点.%Based According to the characteristics of fluid flow in low permeability reservoir, a method was designed that "unsteady displacement-capillary measurement" determines the minimum starting pressure gradient of low-permeability core. Using the natural low permeability reservoir rocks from Xinjiang Oilfield, the minimum starting pressure of water, oil at irreducible water saturation and initial period of displacement of oil by water were investigated respectively.The result show that when the viscosity of water and oil remained unchanged, the relationship of starting pressure and the gas permeability can be described by power exponential function. The minimum starting pressure of cores can be determined by this experiment method and it has the virtue of operation, short measuring time, accurate date, application, etc.