Microscopic seepage process of gas and water in fractures of tight reservoirs

To investigate the dynamic seepage mechanisms of fluids within fractures of tight reservoirs, a three-dimensional digital core fracture structure of an actual reservoir was constructed based on deep learning segmentation results. First, the fracture connectivity was evaluated. Then, single-phase flo...

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Main Authors: Shiwei HOU, Xunqing LÜ, Suyun MENG, Hao ZHANG, Xiuli DU
Format: Article
Language:zho
Published: Editorial Office of Petroleum Geology and Experiment 2025-05-01
Series:Shiyou shiyan dizhi
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Online Access:https://www.sysydz.net/cn/article/doi/10.11781/sysydz2025030671
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author Shiwei HOU
Xunqing LÜ
Suyun MENG
Hao ZHANG
Xiuli DU
author_facet Shiwei HOU
Xunqing LÜ
Suyun MENG
Hao ZHANG
Xiuli DU
author_sort Shiwei HOU
collection DOAJ
description To investigate the dynamic seepage mechanisms of fluids within fractures of tight reservoirs, a three-dimensional digital core fracture structure of an actual reservoir was constructed based on deep learning segmentation results. First, the fracture connectivity was evaluated. Then, single-phase flow permeability simulation was conducted, and gas-water two-phase flow displacement was studied using a level-set method coupled with Navier-Stokes (N-S) equations, with solutions obtained using the finite element method. The results showed that the deep learning method efficiently and automatically segmented fractures in core images with an accuracy of 85%. Connected fractures played an important role in rock permeability. Different fluid properties affected flow pressure and velocity, thereby affecting permeability. During the displacement simulation, the distribution characteristics of gas and water phases were clearly observed. As the displacement progressed until seepage completion, the fluid saturation in narrow fracture channels remained nearly unchanged, serving as the primary storage space for residual gas phase. Fractures with relatively good connectivity, characterized by great width and straightness, became the main seepage channels where gas recovery rates tended to stabilize. The research findings provide guidance for studying gas-water two-phase flow in fracture spaces of tight reservoirs under microscopic conditions.
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publishDate 2025-05-01
publisher Editorial Office of Petroleum Geology and Experiment
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spelling doaj-art-85ee9c09a64342d5b97d3a67ec6499c42025-08-20T01:56:57ZzhoEditorial Office of Petroleum Geology and ExperimentShiyou shiyan dizhi1001-61122025-05-0147367167910.11781/sysydz2025030671sysydz-47-3-671Microscopic seepage process of gas and water in fractures of tight reservoirsShiwei HOU0Xunqing LÜ1Suyun MENG2Hao ZHANG3Xiuli DU4School of Civil Engineering, Shenyang Jianzhu University, Shenyang, Liaoning 110168, ChinaSchool of Civil Engineering, Shenyang Jianzhu University, Shenyang, Liaoning 110168, ChinaSchool of Civil Engineering, Shenyang Jianzhu University, Shenyang, Liaoning 110168, ChinaSchool of Civil Engineering, Shenyang Jianzhu University, Shenyang, Liaoning 110168, ChinaKey Laboratory of Urban and Engineering Safety and Disaster Reduction of Ministry of Education, Beijing University of Technology, Beijing 100124, ChinaTo investigate the dynamic seepage mechanisms of fluids within fractures of tight reservoirs, a three-dimensional digital core fracture structure of an actual reservoir was constructed based on deep learning segmentation results. First, the fracture connectivity was evaluated. Then, single-phase flow permeability simulation was conducted, and gas-water two-phase flow displacement was studied using a level-set method coupled with Navier-Stokes (N-S) equations, with solutions obtained using the finite element method. The results showed that the deep learning method efficiently and automatically segmented fractures in core images with an accuracy of 85%. Connected fractures played an important role in rock permeability. Different fluid properties affected flow pressure and velocity, thereby affecting permeability. During the displacement simulation, the distribution characteristics of gas and water phases were clearly observed. As the displacement progressed until seepage completion, the fluid saturation in narrow fracture channels remained nearly unchanged, serving as the primary storage space for residual gas phase. Fractures with relatively good connectivity, characterized by great width and straightness, became the main seepage channels where gas recovery rates tended to stabilize. The research findings provide guidance for studying gas-water two-phase flow in fracture spaces of tight reservoirs under microscopic conditions.https://www.sysydz.net/cn/article/doi/10.11781/sysydz2025030671gas-water seepage processfracture structurefracture connectivitydigital coredeep learning segmentationtight reservoir
spellingShingle Shiwei HOU
Xunqing LÜ
Suyun MENG
Hao ZHANG
Xiuli DU
Microscopic seepage process of gas and water in fractures of tight reservoirs
Shiyou shiyan dizhi
gas-water seepage process
fracture structure
fracture connectivity
digital core
deep learning segmentation
tight reservoir
title Microscopic seepage process of gas and water in fractures of tight reservoirs
title_full Microscopic seepage process of gas and water in fractures of tight reservoirs
title_fullStr Microscopic seepage process of gas and water in fractures of tight reservoirs
title_full_unstemmed Microscopic seepage process of gas and water in fractures of tight reservoirs
title_short Microscopic seepage process of gas and water in fractures of tight reservoirs
title_sort microscopic seepage process of gas and water in fractures of tight reservoirs
topic gas-water seepage process
fracture structure
fracture connectivity
digital core
deep learning segmentation
tight reservoir
url https://www.sysydz.net/cn/article/doi/10.11781/sysydz2025030671
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AT xunqinglu microscopicseepageprocessofgasandwaterinfracturesoftightreservoirs
AT suyunmeng microscopicseepageprocessofgasandwaterinfracturesoftightreservoirs
AT haozhang microscopicseepageprocessofgasandwaterinfracturesoftightreservoirs
AT xiulidu microscopicseepageprocessofgasandwaterinfracturesoftightreservoirs