油气勘探开发中阿尔奇公式是评价油气含量的经典模型,该模型适用于粒间孔隙的纯砂岩地层.然而实际油气评价中更多时候是以复杂孔隙结构地层为对象,复杂孔隙结构地层岩电关系却呈现出非阿尔奇特性,这意味着利用阿尔奇公式求取这类储层饱和度的可靠性大大降低.针对以上问题,采用变m、n指数和根据孔隙结构分类建立饱和度模型的方法一定程度上满足了此类地层饱和度评价的要求.但以上方法具有很强的区域性和经验性,没有从根本上解决复杂孔隙结构地层饱和度的准确评价问题.等效岩石组分模型将岩石等效为规则的圆柱体,由串联孔隙体积、并联孔隙体积和骨架体积构成,由许多这样大小不一的孔隙分量并联/串联构成整个岩石的导电体系,并引入孔隙结构系数表示不同孔隙的体积比,精确地描述了由复杂孔隙结构引起的非阿尔奇特性.其应用瓶颈是孔隙结构系数、饱和度因子等关键参数的确定方法.本文以等效岩石组分模型为基础。利用核磁测井资料和球管模型确定孔隙结构系数,根据孔隙结构寻优路径对地层进行分类,以岩电实验数据为基础利用阻尼最小二乘法分类确定模型参数,用等效岩石组分模型迭代计算地层饱和度,从而配套形成基于孔隙结构的饱和度评价方法.岩心实验数据分析和实际应用效果表明基于孔隙结构的饱和度模型与阿尔奇公式相比在复杂孔隙结构地层饱和度评价中具有优越性,在复杂孔隙结构地层含油气饱和度评价中具有良好的应用前景. The Arche equation in oil and gas exploration and development is a classic model for evaluating oil and gas content, which is suitable for pure sandstone formation of intergranular pores. However, in actual oil and gas evaluation, complex pore structure stratigraphy is the target, The relationship shows a non-Archie characteristic, which means that the Archie formula to obtain such reservoir saturation reliability is greatly reduced.In view of the above problems, the use of variable m, n index and pore structure classification based on the establishment of saturation model The method meets the requirements of such saturation assessment to a certain extent, but the above method is highly regional and empirical and does not fundamentally solve the problem of accurate evaluation of formation saturation in complex pore structures.An equivalent rock component model The cylinder, which equates the rock with regularity, consists of a series of pore volume, a parallel pore volume and a framework volume, and the conductive system of the entire rock is formed in parallel / series by many pore components of different sizes and the pore structure coefficient is introduced to represent different pores , Accurately describes the non-Archie characteristics caused by complex pore structure.The bottleneck of its application is The method of determining the key parameters gap structure factor, saturation factor. In this paper an equivalent model-based rock composition. The pore structure coefficient is determined by using NMR logging data and the tube model. The strata are classified according to the optimal path of the pore structure. The model parameters are determined by the damping least squares method based on the experimental data of the rock electrical field. The equivalent rock composition model iteration Calculate the saturation of the formation to form the saturation evaluation method based on the pore structure.Critical data analysis and practical application show that the saturation model based on pore structure is superior to Archie’s formula in the evaluation of formation saturation of complex pore structure It has good application prospect in the evaluation of hydrocarbon saturation in complex pore structure strata.