孔隙微观结构特征对渗透率的影响研究

项目名称： 孔隙微观结构特征对渗透率的影响研究

项目编号： No.41202182

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 董艳辉

作者单位： 中国科学院地质与地球物理研究所

项目金额： 24万元

中文摘要： 长期以来，地下水渗流理论的研究主要集中在宏观尺度上。但在解决一些涉及低渗介质的小尺度问题时，连续介质假设不适用，宏观方法受到了极大限制。尽管渗流的一些微观机理可以通过实验来定性研究，但缺少科学合理的定量描述方法使得渗流理论仍停留在宏观尺度上。为了探索地下水流动的微观机理，本项目从孔隙尺度上展开研究：借助于高分辨率CT三维成像，分析真实介质的孔隙结构特征；尝试采用跨尺度的格子Boltzmann方法建立孔隙微观与宏观特征之间的内在联系。研究将揭示孔隙微观结构特征对介质渗透率的影响规律，及其主控因素。研究成果对于深入认识微观渗流机理具有重要的科学意义。同时，也可为低渗油气资源开发和高放废物地质处置等国家重大工程提供科学指导。

中文关键词： 格子玻尔兹曼；X射线层析成像；渗透率；孔隙率；页岩

英文摘要： Researches of groundwater flow theory have been focused on the macroscopic scale for decades. However, when solving some problems involving low-permeability medium on small scale, the macro-scale flow theory is limited because the continuity assumption cannot be applied. Although some experiments can be used to study the microscopic mechanism of groundwater flow, the lack of a reasonable and quantitative description method makes the flow theory still work on the macroscopic scale. In order to reveal the microscopic mechanism of groundwater flow, research is conducted under the pore scale in this study. Characteristics of pore microstructure are analyzed through high-resolution CT and the contact between the micro-scale and macro-scale characteristics is established with the lattice Boltzmann method. The study aims to reveal effects of pore structure characteristics on permeability. The results have important significance in understanding microscopic flow mechanism. In addition, achievements of this study can also support some important engineering projects such as exploitation of oil and gas reservoirs with low permeability and high-level radioactive waste disposal.

英文关键词： Lattice Boltzmann；X-ray Computed Tomography；Permeability；Porosity；Shale