Experimental characterization of damage during geothermal production of hot dry rocks: comprehensive effects of the damage-elastic deformation on conductivity evolution
The development of hot dry rocks (HDRs) is of great significance to adjusting energy structure, alleviating energy shortage, reducing pollution, etc. Low-permeability granite is the predominant rock type in deep HDRs, making fractures the primary pathways for fluid circulation and heat extraction. T...
| Main Authors: | , , , , , |
|---|---|
| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2024
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/180144 |
| _version_ | 1811688574429429760 |
|---|---|
| author | Xu, Fuqiang Shi, Yu Song, Xianzhi Wu, Wei Song, Guofeng Li, Shuang |
| author2 | School of Civil and Environmental Engineering |
| author_facet | School of Civil and Environmental Engineering Xu, Fuqiang Shi, Yu Song, Xianzhi Wu, Wei Song, Guofeng Li, Shuang |
| author_sort | Xu, Fuqiang |
| collection | NTU |
| description | The development of hot dry rocks (HDRs) is of great significance to adjusting energy structure, alleviating energy shortage, reducing pollution, etc. Low-permeability granite is the predominant rock type in deep HDRs, making fractures the primary pathways for fluid circulation and heat extraction. The production of HDRs is significantly influenced by variable fracture conductivity, but current conductivity characterization primarily relies on the elastic deformation of the matrix, neglecting the impact of damage. Accordingly, we propose an experimental method and a supporting apparatus, which is used to unveil the conductivity evolution characteristics resulting from the comprehensive effects of damage and elastic deformation. The experimental results demonstrate that when subjected to confining force squeezing inward, the fracture conductivity experiences varying degrees of decrease compared to its initial state before the experiment. By utilizing the conductivity evolution rate as the evaluation criterion and conducting grey correlation analysis, it has been determined that temperature exerts the most significant influence on the conductivity evolution, followed by injection flow, and lastly, confining pressure. Moreover, rock particle types and production cycles also have different degrees of effect. After considering the comprehensive effects of damage-elastic deformation at the field-scale, the damage has a positive effect on conductivity enhancement. Our study provides a new approach for the characterization of fracture conductivity evolution for deep geothermal projects. |
| first_indexed | 2024-10-01T05:34:22Z |
| format | Journal Article |
| id | ntu-10356/180144 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:34:22Z |
| publishDate | 2024 |
| record_format | dspace |
| spelling | ntu-10356/1801442024-09-18T07:52:19Z Experimental characterization of damage during geothermal production of hot dry rocks: comprehensive effects of the damage-elastic deformation on conductivity evolution Xu, Fuqiang Shi, Yu Song, Xianzhi Wu, Wei Song, Guofeng Li, Shuang School of Civil and Environmental Engineering Engineering Hot dry rocks Injection experiment The development of hot dry rocks (HDRs) is of great significance to adjusting energy structure, alleviating energy shortage, reducing pollution, etc. Low-permeability granite is the predominant rock type in deep HDRs, making fractures the primary pathways for fluid circulation and heat extraction. The production of HDRs is significantly influenced by variable fracture conductivity, but current conductivity characterization primarily relies on the elastic deformation of the matrix, neglecting the impact of damage. Accordingly, we propose an experimental method and a supporting apparatus, which is used to unveil the conductivity evolution characteristics resulting from the comprehensive effects of damage and elastic deformation. The experimental results demonstrate that when subjected to confining force squeezing inward, the fracture conductivity experiences varying degrees of decrease compared to its initial state before the experiment. By utilizing the conductivity evolution rate as the evaluation criterion and conducting grey correlation analysis, it has been determined that temperature exerts the most significant influence on the conductivity evolution, followed by injection flow, and lastly, confining pressure. Moreover, rock particle types and production cycles also have different degrees of effect. After considering the comprehensive effects of damage-elastic deformation at the field-scale, the damage has a positive effect on conductivity enhancement. Our study provides a new approach for the characterization of fracture conductivity evolution for deep geothermal projects. The authors would like to acknowledge the National Natural Science Foundation of China (Grant No. 52104034, 52374010), the Major Program of the National Natural Science Foundation of China (Grant No. 52192624), New Interdisciplinary Discipline Cultivation Fund of Southwest Jiaotong University (Grant No.2682023ZTPY030, 2682022KJ034), the China Scholarship Council (Grant No. 202206440098). 2024-09-18T07:52:19Z 2024-09-18T07:52:19Z 2024 Journal Article Xu, F., Shi, Y., Song, X., Wu, W., Song, G. & Li, S. (2024). Experimental characterization of damage during geothermal production of hot dry rocks: comprehensive effects of the damage-elastic deformation on conductivity evolution. Energy, 294, 130871-. https://dx.doi.org/10.1016/j.energy.2024.130871 0360-5442 https://hdl.handle.net/10356/180144 10.1016/j.energy.2024.130871 2-s2.0-85187225327 294 130871 en Energy © 2024 Elsevier Ltd. All rights reserved. |
| spellingShingle | Engineering Hot dry rocks Injection experiment Xu, Fuqiang Shi, Yu Song, Xianzhi Wu, Wei Song, Guofeng Li, Shuang Experimental characterization of damage during geothermal production of hot dry rocks: comprehensive effects of the damage-elastic deformation on conductivity evolution |
| title | Experimental characterization of damage during geothermal production of hot dry rocks: comprehensive effects of the damage-elastic deformation on conductivity evolution |
| title_full | Experimental characterization of damage during geothermal production of hot dry rocks: comprehensive effects of the damage-elastic deformation on conductivity evolution |
| title_fullStr | Experimental characterization of damage during geothermal production of hot dry rocks: comprehensive effects of the damage-elastic deformation on conductivity evolution |
| title_full_unstemmed | Experimental characterization of damage during geothermal production of hot dry rocks: comprehensive effects of the damage-elastic deformation on conductivity evolution |
| title_short | Experimental characterization of damage during geothermal production of hot dry rocks: comprehensive effects of the damage-elastic deformation on conductivity evolution |
| title_sort | experimental characterization of damage during geothermal production of hot dry rocks comprehensive effects of the damage elastic deformation on conductivity evolution |
| topic | Engineering Hot dry rocks Injection experiment |
| url | https://hdl.handle.net/10356/180144 |
| work_keys_str_mv | AT xufuqiang experimentalcharacterizationofdamageduringgeothermalproductionofhotdryrockscomprehensiveeffectsofthedamageelasticdeformationonconductivityevolution AT shiyu experimentalcharacterizationofdamageduringgeothermalproductionofhotdryrockscomprehensiveeffectsofthedamageelasticdeformationonconductivityevolution AT songxianzhi experimentalcharacterizationofdamageduringgeothermalproductionofhotdryrockscomprehensiveeffectsofthedamageelasticdeformationonconductivityevolution AT wuwei experimentalcharacterizationofdamageduringgeothermalproductionofhotdryrockscomprehensiveeffectsofthedamageelasticdeformationonconductivityevolution AT songguofeng experimentalcharacterizationofdamageduringgeothermalproductionofhotdryrockscomprehensiveeffectsofthedamageelasticdeformationonconductivityevolution AT lishuang experimentalcharacterizationofdamageduringgeothermalproductionofhotdryrockscomprehensiveeffectsofthedamageelasticdeformationonconductivityevolution |