Numerical computation from high‐resolution 3‐D microtomographic images of rocks (known as digital rock physics) has the potential to predict elastic properties more accurately. However, successful examples are limited to samples with simple structure and mineralogy. The physical size of sample is often too small to present heterogeneities at a larger scale and the image resolution is insufficient to characterize the details of rocks. Also, the grayscale values of different minerals in microtomographic images are often similar, and previous attempts to segment them as separate phases are not very successful. Here, we propose a practical digital rock physics workflow for somewhat more complex and ubiquitous rocks, namely, sandstones that contain mostly quartz and a small fraction of dispersed clay (known as arenites). Based on a set of images, we obtain a suite of postcomputation corrections to compensate for the effects of sample size and resolution of the microtomographic images. Furthermore, we build a segmentation workflow that effectively detects feldspar and clay minerals, despite their grayscale similarity to quartz. A moduli‐porosity trend is derived from the subsamples of the original digital images. Bulk moduli agree well with the ultrasonic measurements on the dry samples at 40 MPa. Shear moduli remain overestimated, which is likely caused by poor knowledge of the mineral stiffness. We compensate for this effect using a heuristic correction to the matrix moduli. The final version of the workflow provides accurate elastic moduli trends with porosity and clay content based on only two samples of Bentheimer sandstone.

中文翻译：

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显微照片中的钙钛矿的弹性模量：实用的数字岩石物理工作流程

岩石的高分辨率3D显微照片图像（称为数字岩石物理学）的数值计算有可能更准确地预测弹性。但是，成功的例子仅限于具有简单结构和矿物学的样品。样品的物理尺寸通常太小，不足以在更大范围内呈现异质性，并且图像分辨率不足以表征岩石的细节。同样，显微断层图像中不同矿物的灰度值通常很相似，并且以前尝试将它们分割为单独的相并不是很成功。在这里，我们提出了一种实用的数字岩石物理学工作流程，用于处理较为复杂和普遍存在的岩石，即主要包含石英和少量分散粘土（称为砂岩）的砂岩。根据一组图像，我们获得了一套后期计算校正，以补偿样本量和显微断层图像分辨率的影响。此外，尽管其长石和粘土矿物与石英的灰度相似，我们仍建立了可有效检测长石和粘土矿物的分段工作流程。模孔隙率趋势是从原始数字图像的子样本中得出的。体积模量与干燥样品在40 MPa下的超声测量结果非常吻合。剪切模量仍然被高估，这很可能是由于对矿物刚度的了解不足所致。我们使用启发式校正矩阵模量来补偿这种影响。该工作流程的最终版本仅基于两个Bentheimer砂岩样品提供了具有孔隙率和粘土含量的精确弹性模量趋势。