AccScience Publishing / JSE / Online First / DOI: 10.36922/JSE025420090
ARTICLE

Identification and characterization of fractured cavities in carbonate reservoirs using Swin-UNet transformer and seismic attribute compression fusion

Yunhao Cui1,2 Yuhua Chen1,2* Chao Xu1,2 Yaping Huang3 Qiang Guo3 Zhiqiang Lu4 Zhanpeng Chen1,2 Yuwen Qian1,2
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1 Key Laboratory of Coalbed Methane Resource & Reservoir Formation Process, Ministry of Education, School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu, China
2 Department of Geo-information Science, School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu, China
3 Department of Geophysics, School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu, China
4 Research Institute of Exploration and Exploitation, Sinopec Northwest China Petroleum Bureau, Urumqi, Xinjiang Uyghur Autonomous Region, China
Submitted: 14 October 2025 | Revised: 13 November 2025 | Accepted: 12 December 2025 | Published: 5 January 2026
© 2026 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ )
Abstract

Identifying and characterizing fractured cavities is essential for exploring carbonate reservoirs. However, characterizing the development and distribution of fractured cavities through post-stack seismic attribute analysis remains challenging. Recently, convolutional neural networks (CNNs), such as UNet and its enhanced versions, have enabled the quantitative identification of fractured cavities. Despite these advancements, the local receptive field and weight-sharing mechanisms of these CNNs limit their capability to capture long-range features within strike–slip fault systems. In addition, neural networks are inherently affected by data uncertainty. To address these challenges, a two-step methodology is proposed. The first step utilizes a Swin-UNet transformer (UNETR) model, enhanced with an attention gate, to interpret fractured cavities. The transformer in Swin-UNETR improves the detection of fractured cavities in strike–slip fault zones, whereas the attention gate enhances the recognition of small fractured cavities by increasing their response in the feature maps. This enhanced Swin-UNETR model overcomes the limitations in modeling long-range features. In the second step, the fractured-cavity identification results are combined with seismic attributes from conventional analysis. Principal component analysis is employed both to increase the relative weight of the neural network recognition results in the attribute fusion and to reduce the uncertainty associated with any single identification method. The methodology was validated in the Shunbei area, yielding horizontal segmentation and vertical zonation of fractured cavities, as well as their characterization through fixed-grid modeling. By combining deep learning-based feature extraction with seismic attributes, this approach improves the accuracy of fractured cavity identification and characterization in carbonate reservoirs.

Keywords
Fractured cavity identification and characterization
Seismic attribute compression fusion
Convolutional neural network
Funding
This work was supported by the National Natural Science Foundation of China (Grant no. 42274180) and the Graduate Innovation Program of China University of Mining and Technology (Grant no. 2025WLJCRCZL003).
Conflict of interest
Qiang Guo is an Editorial Board Member of this journal, but was not in any way involved in the editorial and peer-review process conducted for this paper, directly or indirectly. The authors declare they have no competing interests.
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Journal of Seismic Exploration, Print ISSN: 0963-0651, Published by AccScience Publishing