Optimization of pore-network characterization of a compacted clay material by TEM and FIB/SEM imaging
Optimization of pore-network characterization of a compacted clay material by TEM and FIB/SEM imaging
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DOI：
10.1016/j.micromeso.2015.11.035
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发表时间：
2016-04-01
影响因子：
5.2
通讯作者：
Pret, Dimitri
中科院分区：
文献类型：
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作者：
Gaboreau, Stephane;Robinet, Jean-Charles;Pret, Dimitri
在富含粘土的沉积岩中，孔隙网络被认为在控制输运特性方面发挥着关键作用。富含粘土的岩石的孔径分布（PSD）、孔隙网络的几何特征和粘土含量是控制通过粘土地层的扩散过程的参数。在过去几年中，通过使用显微成像技术（FIB-nt、BIB、X 射线断层扫描等），研究有助于提高对一些富含粘土的岩石孔隙网络的了解。这些技术对粘土材料的细观结构尺度组织进行成像，但研究强调了在几何形状和连通性方面完整孔隙分布表征的一些局限性。在这里，我们证明我们可以可靠地表征由 FIB-nt 和 TEM 技术支持的粘土材料的孔隙网络，为评估未来的建模任务提供有用的输入数据。研究的材料是一种压实粘土材料，主要由伊利石（一种非膨胀矿物）组成。选择伊利石是为了代表模拟天然粘土岩石的粘土基质的模拟系统。借助这种压实粘土塞，我们能够在孔隙率受控的均质系统上进行工作，从而促进不同方法之间的比较。这项工作中使用的所有技术，无论是整体技术还是微观技术，都表明所有结果都收敛到相似且完整的 PSD。该项目的主要改进是演示如何改进 FIB-nt 技术的常见分辨率限制和数据处理，以识别完全连接的孔隙网络。 (C) 2015 年作者。由爱思唯尔公司出版
In clay-rich sedimentary rocks, the pore network is considered to play a key role in controlling transport properties. The pore size distribution (PSD) of clay-rich rocks, the geometrical features of the pore network, and the clay content are parameters governing the diffusion process through clay formations. In the last few years, research has contributed to improving understanding of some clay-rich rock pore networks by using microscopic imaging techniques (FIB-nt, BIB, X-ray tomography, etc.). These techniques image the mesostructure scale organization of clay materials, but the studies have highlighted several limitations for full pore distribution characterization in terms of geometry and connectivity. Here we demonstrate that we can characterize a clay material's pore network supported by FIB-nt and TEM techniques reliably, to provide useful input data for assessing a future modeling task. The material studied was a compacted clay material mainly composed of illite, a non-swelling mineral. Illite was chosen in order to represent an analog system mimicking the clay matrix of natural clay-rocks. With this compacted clay plug we were able to work on homogeneous systems with controlled porosity, facilitating comparison between different methods. All the techniques used in this work, whether bulk or microscopic, show that all results converge to a similar and full PSD. This project's main improvement was to demonstrate how to improve the usual resolution limitations and data handling of FIB-nt techniques in order to recognize a fully connected pore network. (C) 2015 The Authors. Published by Elsevier Inc.