Rock heterogeneity is a key parameter influencing a range of rock properties such as fluid flow and geomechanical characteristics. The previously proposed statistical techniques were able to rank heterogeneity on a qualitative level to different extents; however, they need to select a threshold value for determination of representative elementary volumes (REV), which in turn makes the obtained REV subjective. In this study, an X-ray microcomputed tomography (μCT) technique was used to obtain images from different porous media. A new statistical technique was then used to compute REV, as a measure of heterogeneity, without the necessity of defining a threshold. The performance of the method was compared with other methods. It was shown that the calculated sum of the relative errors of the proposed method was lowest compared to the other statistical techniques for all tested porous media. The proposed method can be applied to different types of rocks for more accurate estimation of a REV.

中文翻译：

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使用 X 射线显微计算机断层扫描的代表性岩石基本体积：一种新的统计方法

岩石非均质性是影响流体流动和地质力学特征等一系列岩石特性的关键参数。先前提出的统计技术能够在不同程度上在定性水平上对异质性进行排序；然而，他们需要选择一个阈值来确定代表性基本体积 (REV)，这反过来又使所获得的 REV 具有主观性。在这项研究中，使用 X 射线显微计算机断层扫描 (μCT) 技术从不同的多孔介质中获取图像。然后使用一种新的统计技术来计算 REV，作为异质性的度量，而无需定义阈值。将该方法的性能与其他方法进行了比较。结果表明，对于所有测试的多孔介质，与其他统计技术相比，所提出方法的相对误差的计算总和最低。所提出的方法可以应用于不同类型的岩石，以更准确地估计 REV。