我国干热花岗岩在不同冷却条件下的力学响应研究进展  

Advances in research on the mechanical responses of hot dry granites under varying cooling conditions in China

作　　者：解经宇 宋继伟[2] 隋建才 赵萌[4] 王韧 曾翀 王建龙 XIE Jingyu;SONG Jiwei;SUI Jiancai;ZHAO Meng;WANG Ren;ZENG Chong;WANG Jianlong(School of Resources and Geosciences,China University of Mining and Technology,Xuzhou 221116,China;No.112 Geological Team,Bureau of Geology and Mineral Exploration and Development of Guizhou Province,Anshun 561000,China;Technology Research Institute of Shandong Energy Group Co.,Ltd.,Jinan 250101,China;State Key Laboratory of Bridge Intelligent and Green Construction of China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China;CNPC Engineering Technology R&D Company Limited,Beijing 102206,China;CNPC Chuanqing Drilling Engineering Company Limited,Chengdu 610056,China)

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116 [2]贵州省地质矿产勘查开发局112地质大队,贵州安顺561000 [3]山东能源集团技术研究总院,山东济南250101 [4]中铁大桥局集团有限公司桥梁智能与绿色建造全国重点实验室,湖北武汉430050 [5]中国石油集团工程技术研究院有限公司,北京102206 [6]中国石油集团川庆钻探工程有限公司,四川成都610056

出　　处：《煤田地质与勘探》2025年第3期126-142,共17页Coal Geology & Exploration

基　　金：国家自然科学基金项目(42102353);中国科协青年人才托举工程项目(2023QNRC001);贵州省科技计划项目(黔科合支撑〔2023〕一般173);贵州省地矿局地质科研项目(黔地矿科合〔2022〕4号)。

摘　　要：【意义】增强型地热系统(EGS)是目前开发干热岩的关键技术手段,在EGS的建设与运行过程中,储层岩石会遇到高温冷却、循环冷却、遇水冷却等多种冷却条件。因此,研究不同冷却条件下花岗岩(典型干热岩)的力学响应特征意义重大。【进展】(1)总结并分析了不同冷却条件(高温自然冷却、遇水冷却、循环冷却)下我国典型花岗岩在力学响应(单轴抗压强度σ_(c)、弹性模量E、抗拉强度σ_(t)和泊松比ν)方面的实验数据,指出温度低于200或300℃时,高温自然冷却后花岗岩的σ_(c)、E和σ_(t)略有降低;温度高于200或300℃时,σ_(c)、E和σ_(t)随温度升高近线性减小。(2)在任意温度下,遇水冷却后花岗岩σ_(c)、E和σ_(t)随温度的升高近线性减小。循环冷却下,在经历第1次循环后花岗岩σ_(c)、E和σ_(t)迅速降低,而当循环次数大于5时,σ_(c)、E和σ_(t)逐渐趋于定值。高温自然冷却下,ν随温度升高而降低,其降幅大于高温遇水冷却条件下的ν。(3)高温花岗岩在不同冷却条件下力学性能劣化的主因是内部微裂纹的起裂和扩展。统计了不同冷却条件下干热花岗岩力学响应数据并分析其内在机理,对力学参数归一化值与温度的关系进行拟合,并提出了经验公式。【展望】提出高温花岗岩岩石力学研究的未来发展趋势,包括干热岩开采与CO_(2)地质封存结合过程中的力学响应、多场−多相−多过程耦合作用下干热岩力学响应、基于干热岩开发过程中的实际条件开展实验研究等,以期为干热岩开发的相关设计、计算和数值模拟提供理论支撑。[Significance]Enhanced geothermal systems(EGSs)serve as a key technique for exploiting hot dry rocks(HDRs)presently.During the construction and operation of EGSs,rocks of the HDR reservoirs will experience various cooling conditions,such as natural cooling,cyclic cooling,and water cooling,rendering it greatly significant to investigate the mechanical response characteristics of granites−typical HDRs−under varying cooling conditions.[Advances]This study offers a summary and analysis of experimental data about the mechanical responses,i.e.,uniaxial compressive strength(σ_(c)),elastic modulus(E),tensile strength(σ_(t)),and Poisson's ratio(ν),of typical granites in China under varying cooling conditions including natural,water,and cyclic cooling.The results reveal that after natural cooling,the σ_(c),E,and σ_(t)values of the granites decrease slightly at temperatures below 200℃ or 300℃ but decrease nearly linearly with an increase in temperature at temperatures greater than 200℃ or 300℃.After water cooling,these values decrease nearly linearly with an increase in the temperature at any temperature.Under cyclic cooling,these values decrease rapidly after cooling for the first time and then gradually tend to remain constant after more than five times of cooling.Under natural cooling,the value ofνdecreases with a rise in temperature,with the decreasing amplitude greater than that under water cooling.The deterioration of the mechanical properties of high-temperature granites under varying cooling conditions is primarily due to the generation and propagation of microcracks in them.Based on the statistics and the internal mechanism analysis of the mechanical response data on hot dry granites under varying cooling conditions,this study conducts the fitting of normalized mechanical parameters with temperature and proposes relevant empirical formulas.[Prospects]This study proposes that future research on the mechanical properties of high-temperature granites will focus on the mechanical responses of HDR duri

关 键 词：增强型地热系统 干热岩 花岗岩 不同冷却条件 力学响应 

分 类 号：P314[天文地球—固体地球物理学] TU452[天文地球—地球物理学]