An adjustable bio-sealing method for rock fracture leakage mitigation
This study proposed a repeated adjustable mixture injection strategy (RAM) based microbial induced carbonate precipitation (MICP) for efficient mitigation of rock fracture leakage. Granite fractures with small apertures were investigated, and bio-sealing experiments were conducted using five differe...
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Elsevier
2025-01-01
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| Series: | Journal of Rock Mechanics and Geotechnical Engineering |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S167477552400252X |
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| author | Zhihao Dong Xiaohua Pan Chaosheng Tang Chao Lv Bin Shi |
| author_facet | Zhihao Dong Xiaohua Pan Chaosheng Tang Chao Lv Bin Shi |
| author_sort | Zhihao Dong |
| collection | DOAJ |
| description | This study proposed a repeated adjustable mixture injection strategy (RAM) based microbial induced carbonate precipitation (MICP) for efficient mitigation of rock fracture leakage. Granite fractures with small apertures were investigated, and bio-sealing experiments were conducted using five different cementation solution (CS) concentrations (0.25−2 M). The results showed that the RAM-based bio-sealing method can seal and bond the small aperture rock fractures with high efficiency and uniform precipitation by adjusting the CS concentration. The RAM-based bio-sealing mechanism is attributed to the following four stages: (1) fixation of bacterial flocs onto the fracture surfaces, (2) precipitation of CaCO3 onto the fracture surfaces, (3) growth of pre-precipitated CaCO3 and adhesion of new-suspended CaCO3, and (4) bridging and clogging processes. The optimal CS concentration of 1 M resulted in a fracture filling rate up to 85%, a transmissivity reduction of 4 orders of magnitude, and a shear strength ranging from 512 kPa to 688 kPa. The bio-sealing effect was found to be influenced by the CS concentration on bacterial attachment, calcium carbonate yield and calcium carbonate bulk density. The CS concentration of 1 M promoted bacterial attachment, and increased calcium carbonate yield as well as calcium carbonate bulk density, while concentrations above 1 M had the opposite effect. The bulk density of calcium carbonate played a crucial role in the sealing and bonding performance of bio-sealed fractures, particularly at comparable filling ratios and bridging areas. The bulk density was regulated by the size of calcium carbonate crystals and was determined by Ca2+ concentration in the CS. This study provides valuable insights into the RAM-based bio-sealing method, highlighting its potential for efficient rock fracture leakage mitigation through precise control of CS concentration and understanding the underlying mechanisms. |
| format | Article |
| id | doaj-art-f5e10d9ab1f74156945ab182dddaa4de |
| institution | Kabale University |
| issn | 1674-7755 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Rock Mechanics and Geotechnical Engineering |
| spelling | doaj-art-f5e10d9ab1f74156945ab182dddaa4de2025-01-17T04:49:10ZengElsevierJournal of Rock Mechanics and Geotechnical Engineering1674-77552025-01-01171220232An adjustable bio-sealing method for rock fracture leakage mitigationZhihao Dong0Xiaohua Pan1Chaosheng Tang2Chao Lv3Bin Shi4School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, ChinaSchool of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China; State Key Laboratory for GeoMechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou, 221116, China; Corresponding author. School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China.School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China; Corresponding author.School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, ChinaSchool of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, ChinaThis study proposed a repeated adjustable mixture injection strategy (RAM) based microbial induced carbonate precipitation (MICP) for efficient mitigation of rock fracture leakage. Granite fractures with small apertures were investigated, and bio-sealing experiments were conducted using five different cementation solution (CS) concentrations (0.25−2 M). The results showed that the RAM-based bio-sealing method can seal and bond the small aperture rock fractures with high efficiency and uniform precipitation by adjusting the CS concentration. The RAM-based bio-sealing mechanism is attributed to the following four stages: (1) fixation of bacterial flocs onto the fracture surfaces, (2) precipitation of CaCO3 onto the fracture surfaces, (3) growth of pre-precipitated CaCO3 and adhesion of new-suspended CaCO3, and (4) bridging and clogging processes. The optimal CS concentration of 1 M resulted in a fracture filling rate up to 85%, a transmissivity reduction of 4 orders of magnitude, and a shear strength ranging from 512 kPa to 688 kPa. The bio-sealing effect was found to be influenced by the CS concentration on bacterial attachment, calcium carbonate yield and calcium carbonate bulk density. The CS concentration of 1 M promoted bacterial attachment, and increased calcium carbonate yield as well as calcium carbonate bulk density, while concentrations above 1 M had the opposite effect. The bulk density of calcium carbonate played a crucial role in the sealing and bonding performance of bio-sealed fractures, particularly at comparable filling ratios and bridging areas. The bulk density was regulated by the size of calcium carbonate crystals and was determined by Ca2+ concentration in the CS. This study provides valuable insights into the RAM-based bio-sealing method, highlighting its potential for efficient rock fracture leakage mitigation through precise control of CS concentration and understanding the underlying mechanisms.http://www.sciencedirect.com/science/article/pii/S167477552400252XMICPRock fractureHydraulic and mechanical performanceBio-sealing |
| spellingShingle | Zhihao Dong Xiaohua Pan Chaosheng Tang Chao Lv Bin Shi An adjustable bio-sealing method for rock fracture leakage mitigation Journal of Rock Mechanics and Geotechnical Engineering MICP Rock fracture Hydraulic and mechanical performance Bio-sealing |
| title | An adjustable bio-sealing method for rock fracture leakage mitigation |
| title_full | An adjustable bio-sealing method for rock fracture leakage mitigation |
| title_fullStr | An adjustable bio-sealing method for rock fracture leakage mitigation |
| title_full_unstemmed | An adjustable bio-sealing method for rock fracture leakage mitigation |
| title_short | An adjustable bio-sealing method for rock fracture leakage mitigation |
| title_sort | adjustable bio sealing method for rock fracture leakage mitigation |
| topic | MICP Rock fracture Hydraulic and mechanical performance Bio-sealing |
| url | http://www.sciencedirect.com/science/article/pii/S167477552400252X |
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