数字岩心及孔隙网络模型的构建方法研究

发布时间：2018-05-05 17:06

本文选题：数字岩心 + 孔隙网络模型　；参考：《西南石油大学》2017年硕士论文

【摘要】：数字岩心技术和孔隙网络模型是预测多孔介质流动特性的有效手段,论文对此开展了系统而深入的研究。首先,利用CT机扫描获得岩心图像,通过中值滤波实现岩心扫描图像的去噪,通过OTSU法实现岩心扫描图像的二值化,从而获得岩心孔隙资料。系统研究了马尔科夫-蒙特卡洛(MCMC)法建立数字岩心的理论与方法,在二值化岩心图像的基础上,利用MCMC法建立了数字岩心,通过分析孔隙空间结构的方法评价了数字岩心,表明MCMC法重构的数字岩心能够较好地反映真实岩心的空间结构,证明了 MCMC法适用于重构数字岩心。其次,基于Palagyi和Kuba算法开发了数字岩心孔隙空间拓扑结构的分析方法,首先提取数字岩心孔隙空间中轴线,然后清除长度小于阈值的中轴线、删除由噪音使岩石骨架壁面隆起引起的短小枝节以及合并多余的节点,确保了构建的孔隙中轴线与数字岩心具有等价拓扑结构。以修正后的孔隙网络中轴线为基础,确定孔隙和喉道的位置以及其几何参数,包括:半径、长度、体积及表征孔隙喉道几何特征的形状因子,并结合孔隙中轴线建立了反映数字岩心孔隙空间几何特征的孔隙网络模型,统计分析了孔隙网络模型的几何参数以及拓扑结构。最后详细介绍了论文算法的编程思路、算法的程序实现和数字岩心以及孔隙网络模型的三维可视化。数字岩心和孔隙网络模型是微观尺度上开展多孔介质的流动模拟的研究平台,具有重要的科学意义、学术价值和应用前景。
[Abstract]:Digital core technology and pore network model are effective means to predict the flow characteristics of porous media. Firstly, the core image is obtained by CT scanning, the core scanning image is de-noised by median filter, the core scanning image is binarized by OTSU method, and the core pore data is obtained. The theory and method of establishing digital cores by Markov Monte Carlo method are studied systematically. On the basis of binary core images, digital cores are established by using MCMC method, and the digital cores are evaluated by analyzing pore space structure. It is shown that the digital core reconstructed by MCMC method can better reflect the spatial structure of real core, and that MCMC method is suitable for reconstruction of digital core. Secondly, based on Palagyi and Kuba algorithm, a method of analyzing the topological structure of digital core pore space is developed. Firstly, the center axis of digital core pore space is extracted, and then the center axis whose length is less than the threshold value is removed. Removing the short branches caused by noise and merging redundant nodes ensures that the constructed pore axis and digital core have the equivalent topological structure. Based on the axis of the modified pore network, the position of the pore and throat and their geometric parameters are determined, including radius, length, volume and shape factor, which represent the geometric characteristics of the pore throat. The pore network model which reflects the geometric characteristics of digital core pore space is established based on the axis of the pore center. The geometric parameters and topological structure of the pore network model are analyzed statistically. At last, the programming idea of the algorithm, the program realization of the algorithm and the 3D visualization of the digital core and pore network model are introduced in detail. Digital core and pore network model is the research platform for flow simulation of porous media on micro scale, which has important scientific significance, academic value and application prospect.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE311

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