微观孔隙结构及电阻率指数确定是复杂砂岩储层测井评价的重点难点问题。应用三维阈值分割及形态学滤波技术对铸体薄片进行处理，得到高信噪比的孔隙‐骨架二值图像，结合几何学算法，得到形状因子、孔隙纵横比、等效直径和圆度等微观参数的特征及平均值；通过实验分析了地层因数、胶结指数和迂曲度与这些孔隙微观参数之间的关系。研究表明，地层因数、胶结指数和迂曲度与平均形状因子成幂函数关系，且幂为负数；与平均等效直径成幂函数关系，且幂为正数；岩石孔隙形状越规则，平均等效直径越小，则岩石电阻率越低，地层因数、胶结指数和迂曲度越小。认识孔隙微观参数对电学性质的影响，可以提高测井解释准确率及流体饱和度计算精度。%Determinations of micro‐pore structure and resistivity index are important and difficult problems in complex sandstone reservoir log evaluation .T he casting thin sections are processed by 3D threshold value segmentation and morphological filtering technology to get high signal‐noise ratio images of pore‐skeletons .Combined with the geometry algorithm , the distribution features and the average of microscopic parameters including form factors ,ratio of pore vertical‐horizontal ,equivalent diameter and roundness can be obtained .Analyzed are the relationships among formation factor ,cementing index , tortuosity and those microscopic parameters above . Research shows that formation factor ,cementing index ,and tortuosity give a power exponent relates to average form factor and the power is negative ,give a power exponent relates to average equivalent diameter and the power is positive .More regular the rock pore shape is ,smaller the average equivalent diameter is ,then the rock resistivity is lower ,formation factor ,cementing index ,and tortuosity is smaller .Studied is the influence of microscopic pore structure parameter on electrical properties w hich can help improve accuracy of log interpretation and fluid saturation calculation .
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