岩石孔隙结构表征与流体输运可视化研究进展

Microscopic Pore Structure Characterization and Fluids Transport Visualization of Reservoir Rock

孔隙结构特征的室内测试技术主要分为间接测试和直接测试两大类。前者主要以获取孔径分布等特征统计参数为主的流体注入法及孔隙流体饱和度的反分析法。后者主要为以获取孔隙结构图像为目的的光学辐射法。微观渗流物理实验可以实现孔隙空间中流体流动形态的可视化监测与分析,获取宏观条件下难以观测的实验现象,有助于孔隙尺度下渗流及驱替过程中复杂流动行为的微观力学机制分析。基于岩芯微观孔隙结构图像的模型重建是一种实现孔隙结构精细化表征与流体输运特性可视化研究的数值分析手段。基于不同的表征思想,多孔介质内流体输运控制方程可分为分子动力学模拟、格子玻尔兹曼模拟和计算流体动力学模拟。主要通过泊肃叶定律和准静态模型实现孔隙尺度流体流动和驱替过程的模拟。

The techniques for pore structure acquiring and characterization are divided into two types： indirect testing and direct testing. The former consist of the fluid injection method and the inverse analysis method which obtain the statistic parameters such as pore size distribution. The latter are mainly the optics and radiation methods which obtain the image of pore structure directly. The micro-seepage physical experiment plays an important role in the mechanical mechanism study on pore-scale complex transport behaviors during the seepage and displacement process, and can realize visual monitoring and capture of fluid shape and distribution in pore space, which are difficult to obtain under macroscopic condition. The pore-scale model reconstruction method based on the pore structure images is a numerical modelling process for visual study on pore structure characterization and transport properties prediction. According to the different representation scales, the governing equations of fluid flow- in porous media can be divided into the Molecular Dynamics （MD）, the Lattice Boltzmann method （LBM） and the Computational Fluid Dynamics （CFD）. Besides, the Poiseuille law- and quasi-static model are commonly utilized to model fluid flow- and displacement process in pore network model.