某些砂岩孔隙结构的分形特征

FRACTAL FEATURES OF SOME SANDSTONE PORE STRUCTURES

对我国西部某些深部钻井的砂岩岩芯自然断面的孔隙结构，用扫描电子显微镜（ＳＥＭ）进行观察，得到数字化的图像。用计算机对图像数据进行分形数值分析，得到这些砂岩孔隙空间的分形几何结构，并求出了分维值。样品的分维值在２．６５～２．７１之间，分维值互相接近。将所得结果与Ｋａｔｚ等（１９８５）取自美国的砂岩样品比较，它们的分维值在２．５～２．８之间，说明两地砂岩有相似的结构。分维值可作为估算岩石孔隙结构的一个参数。

The microstructure of some sandstone samples is observed by the scanning electron microscope(SEM). Its digital images are analyzed by computer. The technique involves digitizing the images, filtering, counting geometrical features as a function of feature size, and fitting feature histogrames. The fractal dimension is obtained to range from 2.66～2.71 for five sandstone samples and the results are discussed.