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ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Petrology

Volume 13 - 2025 | doi: 10.3389/feart.2025.1572136

Classification and origin of pore throat systems in tight sandstone reservoirs: A case study of the Xujiahe Formation in the northeastern Sichuan Basin, China

Provisionally accepted
Youzhi Wang Youzhi Wang 1*Xiandong Wang Xiandong Wang 1Xuqiang Chen Xuqiang Chen 1Xiaohui Li Xiaohui Li 1Jingfeng Wu Jingfeng Wu 1Xiang Gao Xiang Gao 1Jianliang Peng Jianliang Peng 1Biao Wang Biao Wang 1Yingyi Xie Yingyi Xie 1Haiguang Wu Haiguang Wu 2
  • 1 China Petroleum Daqing Oilfield Exploration and Development Research Institute, Daqing, China
  • 2 School of Earth Sciences, Northeast Petroleum University, Daqing, China

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

    The reservoirs of the Xujiahe Formation in the northeastern Sichuan Basin have complex rock components, strongpore-throat inhomogeneity, and large differences in production capacity between wells, and the mechanism of high-quality pore-throat development must be clarified to support well deployment. Taking the tight sandstone reservoirs of the Xu-2 member of the Xujiahe Formation as the research object, this study establishes a pore throat systems classification, reveals the origins of various pore throat systems, and conducts a microscopic analysis of the pore structure through thin sections, mercury intrusion capillary pressures, and nuclear magnetic resonance studies.The results show that four main types of reservoir spaces can be found in the cast thin section, including primary InterP pores, residual InterP pores, dissolution pores and IntraP pores. By observing the cast thin section, the pore throat system can be classified into 3 categories: InterP pore-throat systems, mixed InterP-dissolutional pore-throat systems, and dissolution-IntraP pore-throat systems. The pore-throat systems of the reservoir are controlled by both the sedimentary environment and diagenesis, strong hydrodynamics, high quartz grain contents, low mud and calcareous clast contents and moderate amounts of volcanic clasts the are favourable for chlorite film formation. A large number of intergranular pores are efficiently maintained, forming an intergranular pore-throat system with the best storage conditions. The research results can guide the study of the formation mechanism of the tight reservoirs in this area, and also provide some reference for the evaluation ofreservoir consistency.

    Keywords: Tight sandstone, pore throat systems, Reservoir origin, Xujiahe Formation, Sichuan Basin

    Received: 06 Feb 2025; Accepted: 24 Mar 2025.

    Copyright: © 2025 Wang, Wang, Chen, Li, Wu, Gao, Peng, Wang, Xie and Wu. 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: Youzhi Wang, China Petroleum Daqing Oilfield Exploration and Development Research Institute, 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.

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