The conventional digital core models are usually small in size and have difficulty in representing the complex structures of heterogeneous rocks; Therefore, the parameters of simulated rock physics are difficult to be referenced. In this study, we propose a feasible simulation method for obtaining multi-scale and multi-component digital cores based on three types of sandstone samples. In the proposed method, the plug and subplug samples are scanned via micro-computed tomography at different resolutions. Furthermore, the images are precisely registered using the proposed hybrid image registration method. In case of high-resolution images, the traditional segmentation method is used to segment the cores into pores and minerals. Subsequently, we established the relations between the gray values and the porosity/mineral content in case of the low-resolution images based on the registered domains and the relation curves were applied to the segmentation of the low-resolution images. The core images constitute the multi-scale and multi-component digital core models after segmentation. Further, the elastic properties of the three samples were simulated at both fine and coarse scales based on the multi-scale and multi-component digital core models, and four component models were considered. The results show that the multi-scale and multi-component digital core models can overcome the representative limits of the conventional digital core models and accurately characterize pores and minerals at different scales. The numerical results of the elastic modulus are more representative at large scales, and considerably reliable results can be obtained by appropriately considering the minerals.

中文翻译：

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多尺度，多组成数字核心的构建与弹性性能模拟

常规的数字岩心模型通常尺寸较小，难以表示非均质岩石的复杂结构。因此，模拟岩石物理参数难以参考。在这项研究中，我们提出了一种可行的模拟方法，该方法可基于三种类型的砂岩样本获得多尺度和多分量的数字核。在提出的方法中，通过微计算机断层扫描以不同的分辨率扫描插头和子插头样品。此外，使用所提出的混合图像配准方法来精确配准图像。如果是高分辨率图像，则使用传统的分割方法将岩心分割为孔隙和矿物。后来，我们基于配准域建立了低分辨率图像的灰度值与孔隙率/矿物质含量之间的关系，并将关系曲线应用于低分辨率图像的分割。分割后，核心图像构成了多尺度，多分量的数字核心模型。此外，基于多尺度和多分量数字核心模型，分别在精细和粗糙尺度上模拟了三个样本的弹性特性，并考虑了四个分量模型。结果表明，多尺度，多分量的数字岩心模型可以克服常规数字岩心模型的代表性局限，可以准确表征不同尺度的孔隙和矿物质。