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ORIGINAL RESEARCH article

Front. Earth Sci.
Sec. Solid Earth Geophysics
Volume 13 - 2025 | doi: 10.3389/feart.2025.1538316
This article is part of the Research Topic Advances in Petrophysics of Unconventional Oil and Gas View all articles

Multi-scale characterization of tight carbonate rocks based on digital cores

Provisionally accepted
Changsheng Wang Changsheng Wang 1Lili Tian Lili Tian 1Chuanrui Sun Chuanrui Sun 2Yuwei Deng Yuwei Deng 2Ying Zhou Ying Zhou 2*Xin Nie Xin Nie 2,3*
  • 1 Exploration and Development Research Institute, PetroChina Changqing Oilfield Company, Xi'an, China
  • 2 Key Laboratory of Exploration Technologies for Oil and Gas Resources, Yangtze University, Wuhan, Hebei Province, China
  • 3 School of Geophysics and Petroleum Resources, Yangtze University, Wuhan, China

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

    The characterization of carbonate microstructure is of great significance for the evaluation of carbonate oil and gas resources. However, due to the complexity and heterogeneity of the pore structure of tight carbonate rocks, high-pressure mercury intrusion, nuclear magnetic resonance (NMR) and other methods have different limitations in the characterization. This study takes tight carbonate core samples in the fourth member of the Ordovician Majiagou Formation in the Ordos Basin as the research object, and the rock physics experiments, computed tomography (CT), high resolution large-scale backscatter scanning electron microscopy (MAPS), quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN) and focused ion beam-scanning electron microscopy (FIB-SEM) was utilized to characterize the pore structure from micrometer to nanometer, revealing the main mineral composition, and systematically analyzing the relationship between different mineral and pore structures.The results show that the microscopic reservoir space in the study area is mainly composed of inter-crystalline pores, intra-crystalline pores and microfractures; there are obvious differences in the pore structure of different lithologies. The samples with more dolomite have the largest number of pores and throats, the largest coordination number, and the best connectivity; the samples with more calcite have the smallest pore radius. The presence of quartz is conducive to the preservation of pores. This multiscale characterization method using digital core technology provides us with comprehensive pore characteristic, provides important clues for further understanding the pore structure of tight carbonate reservoirs.

    Keywords: Tight carbonate rocks, Digital core technology, Multi-scale characterization, Pore structure, Ordos Basin

    Received: 02 Dec 2024; Accepted: 09 Jan 2025.

    Copyright: © 2025 Wang, Tian, Sun, Deng, Zhou and Nie. 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:
    Ying Zhou, Key Laboratory of Exploration Technologies for Oil and Gas Resources, Yangtze University, Wuhan, Hebei Province, China
    Xin Nie, School of Geophysics and Petroleum Resources, Yangtze University, Wuhan, China

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