ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Solid Earth Geophysics

Volume 13 - 2025 | doi: 10.3389/feart.2025.1551826

This article is part of the Research TopicAdvanced Materials and Technologies for Sustainable Development of Underground ResourcesView all 51 articles

Microstructure characterization of tight reservoirs using micro-CT and FIB-SEM imaging technology

Provisionally accepted
Wei  LiuWei Liu1Lin  ShangLin Shang1Guangliang  GaoGuangliang Gao1Dan  LiDan Li1Miao  WangMiao Wang1Wenshuang  GengWenshuang Geng1Qian  JiaQian Jia1Guodong  ZhangGuodong Zhang1Pengfei  HaoPengfei Hao2Licai  PengLicai Peng2Haixiang  ZhangHaixiang Zhang2*
  • 1Jidong Oilfield Exploration and Development Research Institute, Tangshan, China
  • 2Tsinghua University, Beijing, Beijing, China

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

This study presents a comprehensive investigation into the intricate microstructural characteristics of tight reservoir rocks, utilizing advanced micro-CT scanning and FIB-SEM technologies. Micro-CT scanning technology was employed to obtain clear micro-pore structures and pore-throat size distribution patterns of four typical lithologies: dolomite, sandstone, mudstone, and conglomerate. Our findings reveal that the average pore-throat dimensions in tight reservoirs are confined to several micrometers, markedly diminutive by 1-2 orders of magnitude compared to their conventional counterparts. The FIB-SEM was used to obtain the distribution patterns of nanoand micrometer-scale pore-throats in tight cores. Nano-scale pores with equivalent diameters below 200nm accounted for 20% of the total pore area, contributing minimally to storage space and permeability, while the main storage space and flow channels were concentrated in micrometerscale pore-throats. Three-dimensional micro-CT scanning provides a comprehensive and intuitive digital rock structure for establishing permeability models, while nano-scale two-dimensional scanning yields finer microscopic pore-throat structures and size distribution patterns. The combination of both methods leads to measurement results closer to reality. Conclusively, we propose a mathematical formulation for predicting the absolute permeability of tight reservoirs, predicated on micro-scan data. This formulation is distinguished by its generality, computational simplicity, and its potential to furnish essential data for the design of reservoir development strategies.

Keywords: Microstructure characterization, Tight reservoirs, micro-CT, FIB-SEM, Permeability

Received: 26 Dec 2024; Accepted: 19 May 2025.

Copyright: © 2025 Liu, Shang, Gao, Li, Wang, Geng, Jia, Zhang, Hao, Peng and Zhang. 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: Haixiang Zhang, Tsinghua University, Beijing, 100084, Beijing, China

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