Microscopic pore-fracture combination types and their impact on exploration and development: in case of deep shale gas reservoirs in the Luzhou area of the Sichuan Basin

Micro-pores and micro-fractures constitute the most vital reservoir spaces and seepage pathways for shale gas. Conducting an in-depth study of pore-fracture combination types within shale gas reservoirs is beneficial for understanding shale gas enrichment and exploitation. In this study, we conducte...

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Main Authors: Zhiming Hu, Xianggang Duan, Yonghong Fu, Yan Chang, Jin Chang, Yuqiang Jiang, Linyao Yu
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-08-01
Series:Frontiers in Earth Science
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Online Access:https://www.frontiersin.org/articles/10.3389/feart.2025.1640726/full
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author Zhiming Hu
Zhiming Hu
Xianggang Duan
Xianggang Duan
Yonghong Fu
Yan Chang
Yan Chang
Jin Chang
Jin Chang
Yuqiang Jiang
Linyao Yu
author_facet Zhiming Hu
Zhiming Hu
Xianggang Duan
Xianggang Duan
Yonghong Fu
Yan Chang
Yan Chang
Jin Chang
Jin Chang
Yuqiang Jiang
Linyao Yu
author_sort Zhiming Hu
collection DOAJ
description Micro-pores and micro-fractures constitute the most vital reservoir spaces and seepage pathways for shale gas. Conducting an in-depth study of pore-fracture combination types within shale gas reservoirs is beneficial for understanding shale gas enrichment and exploitation. In this study, we conducted a joint experiment involving MICP and WM impregnation on the main gas-producing layer of Longmaxi formation shale reservoir from five shale gas wells in the Luzhou area. This study achieved the visualization of MICP experiments, enabling a quantitative classification of pore volume and micro-fracture volume within the shale reservoir. A QP-F parameter system for classifying pore-fracture combination types has been established to evaluate pore-fracture connectivity, which are categorized into three types. The strongly connected pore-fracture type (SCPFT) shale gas reservoir in the study area has the characteristics of high porosity, high gas content and strong pore-fracture connectivity, which is the preferred target for shale gas exploration and development. Moderately connected pore-fracture type (MCPFT) and weakly connected pore-fracture type (WCPFT) shale gas reservoirs exhibit significant variations in porosity and gas content, coupled with weak pore-fracture connectivity. Despite some of these reservoirs possessing high porosity and gas content, they fail to achieve high production rates. Therefore, during the development of these two types of shale gas reservoirs, it is imperative to enhance and optimize fracturing techniques to create a more intricate fracture network structure, thereby enabling the release of shale gas trapped in poorly connected pores. This research holds significant theoretical and practical implications for identifying optimal shale gas development zones and improving gas recovery efficiency.
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spelling doaj-art-dc0dc3efb40e49529829fcd91ffcbc802025-08-20T03:57:09ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632025-08-011310.3389/feart.2025.16407261640726Microscopic pore-fracture combination types and their impact on exploration and development: in case of deep shale gas reservoirs in the Luzhou area of the Sichuan BasinZhiming Hu0Zhiming Hu1Xianggang Duan2Xianggang Duan3Yonghong Fu4Yan Chang5Yan Chang6Jin Chang7Jin Chang8Yuqiang Jiang9Linyao Yu10National Energy Shale Gas Research (Experiment) Center, Beijing, ChinaUnconventional Oil and Gas Research Institute, PetroChina Research Institute of Petroleum Exploration & Development, Beijing, ChinaNational Energy Shale Gas Research (Experiment) Center, Beijing, ChinaUnconventional Oil and Gas Research Institute, PetroChina Research Institute of Petroleum Exploration & Development, Beijing, ChinaSchool of Geosciences and Technology, Southwest Petroleum University, Chengdu, Sichuan, ChinaNational Energy Shale Gas Research (Experiment) Center, Beijing, ChinaUnconventional Oil and Gas Research Institute, PetroChina Research Institute of Petroleum Exploration & Development, Beijing, ChinaNational Energy Shale Gas Research (Experiment) Center, Beijing, ChinaUnconventional Oil and Gas Research Institute, PetroChina Research Institute of Petroleum Exploration & Development, Beijing, ChinaSchool of Geosciences and Technology, Southwest Petroleum University, Chengdu, Sichuan, ChinaSichuan Shale Gas Exploration and Development Company Limited, Chengdu, ChinaMicro-pores and micro-fractures constitute the most vital reservoir spaces and seepage pathways for shale gas. Conducting an in-depth study of pore-fracture combination types within shale gas reservoirs is beneficial for understanding shale gas enrichment and exploitation. In this study, we conducted a joint experiment involving MICP and WM impregnation on the main gas-producing layer of Longmaxi formation shale reservoir from five shale gas wells in the Luzhou area. This study achieved the visualization of MICP experiments, enabling a quantitative classification of pore volume and micro-fracture volume within the shale reservoir. A QP-F parameter system for classifying pore-fracture combination types has been established to evaluate pore-fracture connectivity, which are categorized into three types. The strongly connected pore-fracture type (SCPFT) shale gas reservoir in the study area has the characteristics of high porosity, high gas content and strong pore-fracture connectivity, which is the preferred target for shale gas exploration and development. Moderately connected pore-fracture type (MCPFT) and weakly connected pore-fracture type (WCPFT) shale gas reservoirs exhibit significant variations in porosity and gas content, coupled with weak pore-fracture connectivity. Despite some of these reservoirs possessing high porosity and gas content, they fail to achieve high production rates. Therefore, during the development of these two types of shale gas reservoirs, it is imperative to enhance and optimize fracturing techniques to create a more intricate fracture network structure, thereby enabling the release of shale gas trapped in poorly connected pores. This research holds significant theoretical and practical implications for identifying optimal shale gas development zones and improving gas recovery efficiency.https://www.frontiersin.org/articles/10.3389/feart.2025.1640726/fullpore-fracture characteristicpore-fracture combination typeshale gas reservoirlongmaxi formationgeological significance
spellingShingle Zhiming Hu
Zhiming Hu
Xianggang Duan
Xianggang Duan
Yonghong Fu
Yan Chang
Yan Chang
Jin Chang
Jin Chang
Yuqiang Jiang
Linyao Yu
Microscopic pore-fracture combination types and their impact on exploration and development: in case of deep shale gas reservoirs in the Luzhou area of the Sichuan Basin
Frontiers in Earth Science
pore-fracture characteristic
pore-fracture combination type
shale gas reservoir
longmaxi formation
geological significance
title Microscopic pore-fracture combination types and their impact on exploration and development: in case of deep shale gas reservoirs in the Luzhou area of the Sichuan Basin
title_full Microscopic pore-fracture combination types and their impact on exploration and development: in case of deep shale gas reservoirs in the Luzhou area of the Sichuan Basin
title_fullStr Microscopic pore-fracture combination types and their impact on exploration and development: in case of deep shale gas reservoirs in the Luzhou area of the Sichuan Basin
title_full_unstemmed Microscopic pore-fracture combination types and their impact on exploration and development: in case of deep shale gas reservoirs in the Luzhou area of the Sichuan Basin
title_short Microscopic pore-fracture combination types and their impact on exploration and development: in case of deep shale gas reservoirs in the Luzhou area of the Sichuan Basin
title_sort microscopic pore fracture combination types and their impact on exploration and development in case of deep shale gas reservoirs in the luzhou area of the sichuan basin
topic pore-fracture characteristic
pore-fracture combination type
shale gas reservoir
longmaxi formation
geological significance
url https://www.frontiersin.org/articles/10.3389/feart.2025.1640726/full
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