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ORIGINAL RESEARCH article

Front. Earth Sci.
Sec. Solid Earth Geophysics
Volume 12 - 2024 | doi: 10.3389/feart.2024.1518561
This article is part of the Research Topic Experimental and Numerical Simulations of Rock Physics View all 7 articles

Constructions of Multi-scale 3D Digital Rocks by Associated Image Segmentation Method

Provisionally accepted
Haiyan Wang Haiyan Wang 1*Xuefeng Yang Xuefeng Yang 1Cong Zhou Cong Zhou 2Jiaqi Yu Jiaqi Yu 2Kui Xie Kui Xie 1
  • 1 Research Institute of Exploration and Development, PetroChina Daqing Oilfield Co., Ltd., Daqing,, Daqing, China
  • 2 Exploration Division, PetroChina Daqing Oilfield CO., Ltd., Daqing, China, Daqing, China

The final, formatted version of the article will be published soon.

    Digital rocks constructed from micro-CT image at a single-resolution face limitations in accurately identifying the entire pore space and mineral components of tight sandstones, due to their high content of nanoscale pores and clay. Consequently, the porosity values derived from such digital rocks are significantly lower compared to those obtained through laboratory measurements, resulting in discrepancies between the measured and calculated petrophysical properties. This study introduces a multi-scale digital rock modeling method by integrating three-dimensional micro-CT images acquired at two distinct resolutions and two-dimensional SEM images. Plunger-shaped core samples and their corresponding sub-samples were scanned at resolutions of 13.99 μm/voxel and 2.99 μm/voxel, respectively. The scale-invariant feature transform (SIFT) image registration technique was employed to accurately align the two sets of grayscale CT images. Correlation curves between the grayscale value in low-resolution CT images and various mineral contents were established based on the aligned regions, and utilized to construct multi-scale digital rock models. Intragranular pores, unresolvable by the micro-CT images, were identified using SEM imaging, enabling the incorporation of fine-scale features into the models. The resulting multi-scale digital rock models exhibited bulk porosity values that closely matched laboratory helium porosity measurements. Additionally, the elastic moduli calculated by the differential effective medium (DEM) model and the finite element method (FEM) demonstrated good correspondence with experimental results. These results validate the proposed multi-scale digital rock modeling method as an effective approach for accurately characterizing the porosity and mineral components of tight sandstone reservoirs.

    Keywords: Digital rock, image registration, multi-scale, correlation segmentation, Porosity, Elastic Modulus

    Received: 28 Oct 2024; Accepted: 18 Dec 2024.

    Copyright: © 2024 Wang, Yang, Zhou, Yu and Xie. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Haiyan Wang, Research Institute of Exploration and Development, PetroChina Daqing Oilfield Co., Ltd., Daqing,, Daqing, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.