The geomechanical integrity of shale overburden is a highly significant geological risk factor for a range of engineering and energy-related applications including CO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document} storage and unconventional hydrocarbon production. This paper aims to provide a comprehensive set of high-quality nano- and micro-mechanical data on shale samples to better constrain the macroscopic mechanical properties that result from the microstructural constituents of shale. We present the first study of the mechanical responses of a calcareous shale over length scales of 10 nm to 100 μ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu$$\end{document}m, combining approaches involving atomic force microscopy (AFM), and both low-load and high-load nanoindentation. PeakForce quantitative nanomechanical mapping AFM (PF-QNM) and quantitative imaging (QI-AFM) give similar results for Young’s modulus up to 25 GPa, with both techniques generating values for organic matter of 5–10 GPa. Of the two AFM techniques, only PF-QNM generates robust results at higher moduli, giving similar results to low-load nanoindentation up to 60 GPa. Measured moduli for clay, calcite, and quartz-feldspar are 22±2GPa\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$22 \pm 2\,\hbox { GPa}$$\end{document}, 42±8GPa\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$42 \pm 8\,\hbox { GPa}$$\end{document}, and 55±10GPa\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$55 \pm 10\,\hbox { GPa}$$\end{document} respectively. For calcite and quartz-feldspar, these values are significantly lower than measurements made on highly crystalline phases. High-load nanoindentation generates an unimodal mechanical response in the range of 40–50 GPa for both samples studied here, consistent with calcite being the dominant mineral phase. Voigt and Reuss bounds calculated from low-load nanoindentation results for individual phases generate the expected composite value measured by high-load nanoindentation at length scales of 100–600 μ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu$$\end{document}m. In contrast, moduli measured on more highly crystalline mineral phases using data from literature do not match the composite value. More emphasis should, therefore, be placed on the use of nano- and micro-scale data as the inputs to effective medium models and homogenisation schemes to predict the bulk shale mechanical response.

中文翻译：

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使用原子力显微镜和纳米压痕技术对富含有机质钙质页岩进行地质力学表征

页岩覆盖层的地质力学完整性是一系列工程和能源相关应用的非常重要的地质风险因素，包括 CO2\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage {amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document} 存储和非常规碳氢化合物生产。本文旨在提供关于页岩样品的一整套高质量的纳米和微观力学数据，以更好地约束由页岩微观结构成分引起的宏观力学性质。我们首次对钙质页岩在 10 nm 到 100 μ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} 的机械响应进行研究\usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu$$\end{document}m，结合涉及原子力显微镜的方法（ AFM），以及低负载和高负载纳米压痕。PeakForce 定量纳米力学映射 AFM (PF-QNM) 和定量成像 (QI-AFM) 对高达 25 GPa 的杨氏模量给出了相似的结果，这两种技术都产生了 5-10 GPa 的有机物值。在两种 AFM 技术中，只有 PF-QNM 在更高的模量下产生稳健的结果，与高达 60 GPa 的低负载纳米压痕产生相似的结果。和 55±10GPa\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{ \oddsidemargin}{-69pt} \begin{document}$$55 \pm 10\,\hbox { GPa}$$\end{document} 分别。对于方解石和石英长石，这些值明显低于对高度结晶相的测量值。对于这里研究的两个样品，高负载纳米压痕产生 40-50 GPa 范围内的单峰机械响应，与方解石是主要矿物相一致。Voigt 和 Reuss 界限从单个阶段的低负载纳米压痕结果计算生成预期的复合值由高负载纳米压痕在 100–600 μ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym 的长度尺度测量} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu$$\end{文件}米。相比之下，使用文献数据在更高结晶度的矿物相上测量的模量与复合值不匹配。因此，应更加重视使用纳米和微米级数据作为有效介质模型和均质化方案的输入，以预测大块页岩力学响应。