复杂孔隙结构砂岩储层岩电参数研究

Archie' s electrical parameters of complex pore texture in sandstone reservoir

1. 西北大学地质系,陕西西安 710069;2. 长庆油田公司勘探开发研究院,陕西西安 710021

Department of Geology, North west U-niversity, Xi' an 710069, China

描述含油岩石电阻率与饱和度关系的理论基础是经典阿尔奇公式,其应用效果主要取决于合适的岩电参数。复杂孔隙结构砂岩具有低孔低渗、微孔微裂隙发育、非均质性强等特点,其岩电参数特征在许多方面与常规储层存在显著差异。以鄂尔多斯盆地上古生界低渗透砂岩储层岩电实验资料为依据,研究了复杂孔隙结构对储层电学参数的影响,探讨了通过储层分类以及采用可变胶结指数m和饱和度指数n提高低渗透储层饱和度测井评价效果的方法。最后给出了一口井的解释实例。

Archie formula is the classical theory that describes the relationship between the resistivity and water saturation (Sw) of hydrocarbon-bearing sandstone reservoir. The application effect mainly depends on appropriate electrical parameters. Complex pore texture sandstone has low porosity, low permeability, more microporosity, more microfissure andhigh heterogeneity. Its electrical parameters are different evidently with conventional reservoir. On the basis of core electricity experiment data of low permeability sandstone of Upper Palaeozoic in Erdos Basin, the effects of complex pore structure on electrical parameter are investigated, the method to improve the precision of water saturation calculation through reservoir classification and using alterable m and n parameters are analyzed. Finally, a interpretation case of one well is presented.