{"title":"高温热循环下不同冷却方法下花岗岩的物理和机械特性分析","authors":"Haonan Li, Li Yu, Yue Wu, Weihao Wang, Xinyuan Zhang, Yongchuan Zhao","doi":"10.1144/qjegh2023-110","DOIUrl":null,"url":null,"abstract":"This study explores the impact of external pressure and high-temperature erosion on the physical and mechanical properties of granite, the geothermal well storage medium, during geothermal exploitation. Objectives include evaluating the effects of repeated heating and cooling cycles at different temperatures on porosity, permeability, and mechanical performance, with a focus on confining pressure's influence on permeability. Results indicate that under water-cooling and ambient conditions, porosity and permeability increase with cycle repetition, while compressive strength and elastic modulus decrease. Notably, Group B's (water-cooled) mechanical performance surpasses Group A (room temperature cooling) when porosity is below 1.5%. However, with increasing porosity due to thermal cycling, Group B's granite becomes inferior to Group A. CT scans reveal a post-cycling granite pore structure dominated by horizontal cracks, with primary uniaxial compression damage in the vertical direction. Thermal cycling reduces crack paths and load-bearing capacity, diminishing granite's mechanical performance. This study offers insights into subtle interactions between cooling methods and porosity during geothermal energy exploitation. It provides valuable guidance for optimizing geothermal energy use and mitigating potential adverse impacts on rock integrity, laying a foundation for further research and practical applications in geothermal energy exploitation.","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.3000,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Analysis of physical and mechanical properties of granite under different cooling methods under high temperatures thermal cycles\",\"authors\":\"Haonan Li, Li Yu, Yue Wu, Weihao Wang, Xinyuan Zhang, Yongchuan Zhao\",\"doi\":\"10.1144/qjegh2023-110\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"This study explores the impact of external pressure and high-temperature erosion on the physical and mechanical properties of granite, the geothermal well storage medium, during geothermal exploitation. Objectives include evaluating the effects of repeated heating and cooling cycles at different temperatures on porosity, permeability, and mechanical performance, with a focus on confining pressure's influence on permeability. Results indicate that under water-cooling and ambient conditions, porosity and permeability increase with cycle repetition, while compressive strength and elastic modulus decrease. Notably, Group B's (water-cooled) mechanical performance surpasses Group A (room temperature cooling) when porosity is below 1.5%. However, with increasing porosity due to thermal cycling, Group B's granite becomes inferior to Group A. CT scans reveal a post-cycling granite pore structure dominated by horizontal cracks, with primary uniaxial compression damage in the vertical direction. Thermal cycling reduces crack paths and load-bearing capacity, diminishing granite's mechanical performance. This study offers insights into subtle interactions between cooling methods and porosity during geothermal energy exploitation. It provides valuable guidance for optimizing geothermal energy use and mitigating potential adverse impacts on rock integrity, laying a foundation for further research and practical applications in geothermal energy exploitation.\",\"PeriodicalId\":20937,\"journal\":{\"name\":\"Quarterly Journal of Engineering Geology and Hydrogeology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.3000,\"publicationDate\":\"2024-01-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Quarterly Journal of Engineering Geology and Hydrogeology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1144/qjegh2023-110\",\"RegionNum\":4,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ENGINEERING, GEOLOGICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Quarterly Journal of Engineering Geology and Hydrogeology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1144/qjegh2023-110","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
引用次数: 0
摘要
本研究探讨了在地热开采过程中,外部压力和高温侵蚀对地热井存储介质花岗岩的物理和机械性能的影响。研究目标包括评估在不同温度下反复加热和冷却循环对孔隙度、渗透率和机械性能的影响,重点是封闭压力对渗透率的影响。结果表明,在水冷和常温条件下,孔隙度和渗透率会随着循环次数的增加而增加,而抗压强度和弹性模量则会降低。值得注意的是,当孔隙率低于 1.5% 时,B 组(水冷)的机械性能超过了 A 组(室温冷却)。CT 扫描显示,循环后的花岗岩孔隙结构以水平裂缝为主,垂直方向主要是单轴压缩破坏。热循环减少了裂缝路径和承载能力,降低了花岗岩的机械性能。这项研究深入揭示了地热能源开采过程中冷却方法与孔隙度之间微妙的相互作用。它为优化地热能利用和减轻对岩石完整性的潜在不利影响提供了宝贵的指导,为地热能开发的进一步研究和实际应用奠定了基础。
Analysis of physical and mechanical properties of granite under different cooling methods under high temperatures thermal cycles
This study explores the impact of external pressure and high-temperature erosion on the physical and mechanical properties of granite, the geothermal well storage medium, during geothermal exploitation. Objectives include evaluating the effects of repeated heating and cooling cycles at different temperatures on porosity, permeability, and mechanical performance, with a focus on confining pressure's influence on permeability. Results indicate that under water-cooling and ambient conditions, porosity and permeability increase with cycle repetition, while compressive strength and elastic modulus decrease. Notably, Group B's (water-cooled) mechanical performance surpasses Group A (room temperature cooling) when porosity is below 1.5%. However, with increasing porosity due to thermal cycling, Group B's granite becomes inferior to Group A. CT scans reveal a post-cycling granite pore structure dominated by horizontal cracks, with primary uniaxial compression damage in the vertical direction. Thermal cycling reduces crack paths and load-bearing capacity, diminishing granite's mechanical performance. This study offers insights into subtle interactions between cooling methods and porosity during geothermal energy exploitation. It provides valuable guidance for optimizing geothermal energy use and mitigating potential adverse impacts on rock integrity, laying a foundation for further research and practical applications in geothermal energy exploitation.
期刊介绍:
Quarterly Journal of Engineering Geology and Hydrogeology is owned by the Geological Society of London and published by the Geological Society Publishing House.
Quarterly Journal of Engineering Geology & Hydrogeology (QJEGH) is an established peer reviewed international journal featuring papers on geology as applied to civil engineering mining practice and water resources. Papers are invited from, and about, all areas of the world on engineering geology and hydrogeology topics. This includes but is not limited to: applied geophysics, engineering geomorphology, environmental geology, hydrogeology, groundwater quality, ground source heat, contaminated land, waste management, land use planning, geotechnics, rock mechanics, geomaterials and geological hazards.
The journal publishes the prestigious Glossop and Ineson lectures, research papers, case studies, review articles, technical notes, photographic features, thematic sets, discussion papers, editorial opinion and book reviews.