Computation of fractal dimension of rock pores based on gray CT images  

作　　者：PENG RuiDong YANG YanCong JU Yang MAO LingTao YANG YongMing 

机构地区：[1]State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology （Beijing）, Beijing 100083, China [2]School of Mechanical Electronic and Information Engineering, China University of Mining and Technology （Beijing）, Beijing 100083, China

出　　处：《Chinese Science Bulletin》2011年第31期3346-3357,共12页

基　　金：supported by the National Natural Science Foundation of China (10802092, 50974125);the National Basic Research Program of China (2009CB724602, 2010CB226804);the Specialized Research Fund for the Doctoral Program of Higher Education (20070290011);the Fundamental Research Funds for the Central Universities (2009QM03)

摘　　要：The characterization of pore structure in rocks is relevant in determining their various mechanical behaviors. Digital image processing methods integrated with fractal theory were applied to analyze images of rock slices obtained from industry CT, elucidating the characteristics of rock pore structure and the relationship between porosity and fractal dimensions. The gray values of pixels in CT images of rocks provide comprehensive results with respect to the attenuation coefficients of various materials in corresponding rock elements, and these values also reflect the effect of rock porosity at various scales. A segmentation threshold can be determined by inverse analysis based on the pore ratios that are measured experimentally, and subsequently binary images of rock pores can be obtained to study their topological structures. The fractal dimension of rock pore structure increases with an increase in rock pore ratio, and fractal dimensions might differ even if pore ratios are the same. The more complex the structure of a rock, the larger the fractal dimension becomes. The experimental studies have validated that fractal dimension calculated directly from gray CT images of rocks can give an effective complementary parameter to use alongside pore ratios and they can suitably represent the fractal characteristics of rock pores.The characterization of pore structure in rocks is relevant in determining their various mechanical behaviors. Digital image processing methods integrated with fractal theory were applied to analyze images of rock slices obtained from industry CT, elucidating the characteristics of rock pore structure and the relationship between porosity and fractal dimensions. The gray values of pixels in CT images of rocks provide comprehensive results with respect to the attenuation coefficients of various materials in corresponding rock elements, and these values also reflect the effect of rock porosity at various scales. A segmentation threshold can be determined by inverse analysis based on the pore ratios that are measured experimentaUy, and subsequently binary images of rock pores can be obtained to study their topological structures. The fractal dimension of rock pore structure increases with an increase in rock pore ratio, and fractal dimensions might differ even if pore ratios are the same. The more complex the structure of a rock, the larger the fractal dimension becomes. The experimental studies have validated that fractal dimension calculated directly from gray CT images of rocks can give an effective complementary parameter to use alongside pore ratios and they can suitably represent the fractal characteristics of rock pores.

关 键 词：岩石孔隙结构 CT图像 分形理论 维数计算 毛孔 灰色 孔隙结构特征 分形维数 

分 类 号：P624[天文地球—地质矿产勘探]