We demonstrate that the static elastic properties of a carbonate sample, comprised of dolomite and calcite, could be accurately predicted by Digital Rock Physics (DRP), a non-invasive testing method for simulating laboratory measurements. We present a state-of-the-art algorithm that uses X-ray Computed Tomography (CT) imagery to compute the elastic properties of a lacustrine rudstone sample. The high-resolution CT-images provide a digital sample that is used for analyzing microstructures and performing quasi-static compression numerical simulations. Here, we present the modified Segmentation-Less method withOut Targets method: a combination of segmentation-based and segmentation-less DRP. This new method assigns the spatial distribution of elastic properties of the sample based on homogenization theory and overcomes the monomineralic limitation of the previous work, allowing the algorithm to be used on polymineralic rocks. The method starts by partitioning CT-images of the sample into smaller sub-images, each of which contains only two phases: a mineral (calcite or dolomite) and air. Then, each sub-image is converted into elastic property arrays. Finally, the elastic property arrays from the sub-images are combined and fed into a finite element algorithm to compute the effective elastic properties of the sample. We compared the numerical results to the laboratory measurements of low-frequency elastic properties. We find that the Young’s moduli of both the dry and the fully saturated sample fall within 10% of the laboratory measurements. Our analysis also shows that segmentation-based DRP should be used cautiously to compute elastic properties of carbonate rocks similar to our sample.

我们证明，由数字岩石物理学（DRP）可以准确预测由白云石和方解石组成的碳酸盐样品的静态弹性特性，这是一种用于模拟实验室测量值的非侵入性测试方法。我们提出了一种先进的算法，该算法使用X射线计算机断层扫描（CT）图像来计算湖相石板样品的弹性特性。高分辨率的CT图像提供了一个数字样本，该样本用于分析微观结构并执行准静态压缩数值模拟。在这里，我们介绍了经过改进的Segmentation-Less方法和Out Targets方法：基于细分的DRP和基于无细分的DRP的组合。这种新方法基于均质化理论分配了样品弹性特性的空间分布，并克服了先前工作的单矿物限制，使该算法可用于多矿物岩石。该方法首先将样品的CT图像划分为较小的子图像，每个子图像仅包含两个阶段：矿物（方解石或白云石）和空气。然后，将每个子图像转换为弹性属性数组。最后，将来自子图像的弹性属性数组进行合并，并输入到有限元算法中，以计算样本的有效弹性属性。我们将数值结果与低频弹性特性的实验室测量结果进行了比较。我们发现，干燥样品和完全饱和样品的杨氏模量均落在实验室测量值的10％之内。我们的分析还表明，与我们的样本相似，应谨慎使用基于分段的DRP计算碳酸盐岩的弹性特性。