考虑分形特征的岩心扫描图像合理分割方法

考虑岩石的孔隙度和孔隙结构的分形特征的关系,结合图像分割Otsu算法,提出Otsu算法的分形校正算法。首先对三种砂岩岩心的扫描图像进行处理,得到结果与实验结果进行对比,发现分形校正算法能够大大提高图像分割的准确度;此外对致密性气藏岩心和页岩岩心进行处理,分形校正算法的结果同样更接近实验值。由于实验得到为岩心的有效孔隙度,因此比计算值偏小。对于实验难以测量孔隙度的岩心,可以采用Otsu分形校正算法对扫描图像进行处理,得到其孔隙度。

A Reasonable Segmentation Method Considering Fractal Characters For Scanning Image Of Reservoir Rock

Combining the image segmentation method of Otsu, the Otsu fractal correction algorithm is proposed, based on the relationship between porosity and the fractal characters of the pore structure. At first, the results of three kinds of sandstone cores scanned images are compared with experimental results. The accuracy of image segmentation is highly enhanced with the usage of Otsu fractal correction algorithm. Besides, the results of the correction algorithm, which are obtained by processing the images of tight sandstone and shale core, are more close to the experimental values, albeit bigger, which is due to the fact that the results of the experiments are the effective porosities. In conclusion, the Otsu fractal correction algorithm could be utilized to calculate the porosity through processing the scanned images of cores which are difficult to be measured by experiments.