五大连池玄武岩三维孔隙组构的多重分形特征

Multifractality of Basalt Micropores Based on High-Resolution Digital CT Images

通过CT扫描,获得了黑龙江省五大连池火山群中第4层玄武岩样本的1 423张高精度图像,利用数字图像分析方法识别出了玄武岩三维孔隙组构,基于二维切片序列重构了三维孔隙柱体,计算了孔隙的基本统计参数。结合分形与多重分形技术,利用多重分形分析矩方法对三维孔隙结构作了定量研究分析。分析可知,所取玄武岩样品几何结构复杂,非均质性强。多重分形维数谱函数f(α)呈连续分布,f(α)均为不对称的上凸曲线,表明岩石孔隙分布不均匀,具有明显的多重分形特征。三维孔隙结构的多重分形分析及三维重构技术可望进一步为岩心孔隙结构的定量化研究提供微观尺度上的证据。

In this study, high-resolution digital CT images of micro porespaces of a basalt rock from Wu- dalianchi, Heilongjiang Province were obtained by computerized tomography. The pores and outlines of these images were automatically recognized by image analysis technique. In total, 1 423 images were used to visually reconstruct the 3D pore cylinder. Image analysis techniques were applied to extract the pore spaces and several parameters were calculated to quantitatively characterize the pore distributions. In addi- tion, fractal and multifractal methods were also used to quantitatively describe the irregular geometries of 3D pore systems. The results clearly show that the 3D pore spaces are of multifractality, and as a conse- quence, the multifractal analysis of three-dimensional pore structure can provide a further evidence for quantitative study of core pore structure on a microscopic scale.