缝洞型碳酸盐岩油藏水驱油机理物理模拟研究

PHYSICAL SIMULATION OF WATER DISPLACING OIL MECHANISM FOR VUGGY FRACTURED CARBONATE ROCK RESERVOIR

为了更好地认识缝洞型碳酸盐岩油藏的特殊渗流机理,根据某油田缝洞型碳酸盐岩的实际情况设计制作了全直径缝洞型岩芯模型,实验岩样来源于油田的实际岩芯,采用油田实际油样和相似地层水进行了模型水平、倾斜30°、倾斜60°三种不同角度的水驱油机理物理模拟实验,分析实验结果,认为缝洞型碳酸盐岩采收率、含水率、无水采收期等与缝洞倾斜情况和缝洞结构有密切关系。并将实验数据应用于Cruz-HernandezJ等人基于对流-扩散渗流理论建立的缝洞型油水两相流动系统数学模型的拟合中,讨论了数学模型中的空间系数、扩散系数和流动速度对模型拟合的影响情况,并提出了模型的改进应考虑重力作用、流体流速、孔洞配位数等影响因素。

In order to better recognize the special flow mechanism of vuggy fractured carbonate rock reservoir,in this paper,a holo-diameter core model is designed and made based on the actual conditions of a certain vuggy fractured carbonate rock reservoir.The laboratory samples from this reservoir,actual oil sample and similar formation water are used in the simulation experiments of water displacing oil mechanism.These experiments include horizon,30o and 60o angles water displacing oil simulation experiments.The result shows that recovery ratio,water content and breakthrough oil stage of vuggy fractured carbonate are in close connection with vuggy fractured structure.Afterwards,the experimental data are analyzed carefully and used in matching J.Cruz-Hernandez′s vuggy fractured carbonate water/oil two-phase flow mathematical model based on convective diffuse filtration theory.And then,such affecting factors of this model are discussed as the fraction of the porous space,the coefficient of transfer of fluids and flow velocity.At last,the authors propose that the factors of gravity,flow velocity and coordinate number of vugs should be take into consideration in the development of the model.