超临界CO_(2)不同浸泡时间致煤体变形破坏能量演化机制研究  

Study on the energy evolution mechanism of coal deformation and failure induced by varying soaking times of supercritical CO_(2)

作　　者：于永江[1] 邬志强 刘佳铭 YU Yongjiang;WU Zhiqiang;LIU Jiaming(College of Mining,Liaoning Technical University,Fuxin 123000,Liaoning,China)

机构地区：[1]辽宁工程技术大学矿业学院,辽宁阜新123000

出　　处：《安全与环境学报》2025年第2期498-507,共10页Journal of Safety and Environment

基　　金：国家自然科学基金项目(52374092)。

摘　　要：为探究超临界CO_(2)不同浸泡时间(0、5 d、10 d、15 d)下煤体变形破坏全过程中的能量演化机制,以梅花井煤矿4-1煤层的两种煤样(焦煤、弱黏煤)为研究对象,开展了超临界CO_(2)不同浸泡时间下的煤体单轴压缩试验。结果表明:随着超临界CO_(2)浸泡时间的延长,煤体抗压强度及弹性模量均逐渐下降;基于能量计算原理,随着浸泡时间的延长,煤体在压密阶段存在微小量值的能量存储与耗散特征,在线弹性阶段存储弹性应变能的能力逐渐减弱,在塑性屈服阶段耗散能占总应变能的比重逐渐增大,在峰后残余强度阶段耗散能的激增使得煤体产生相互贯通和扩展的宏观裂隙。在此基础上研究煤样的能量累积率与耗散率演化机制,结果表明:在应力峰值前,受到超临界CO_(2)的浸泡会削弱煤体弹性应变能的累积速率;在应力峰值处,煤体的弹性应变能累积速率达到最小;在峰后破坏阶段,随着浸泡时间的延长,煤体超临界CO_(2)浸泡时间达到10 d时,其弹性应变能转化率与耗散率达到最大。此研究成果有助于分析深部煤储层注入CO_(2)压裂过程煤体变形的能量特征,也对CO_(2)的地质封存具有一定参考意义。To investigate the deformation and failure characteristics of various coal types under supercritical CO_(2)conditions,this paper presents systematic experimental research.The experiments included several soaking durations:no soaking(0 d),5 d,10 d,and 15 d.Using laboratory testing and theoretical analysis,this study conducted uniaxial compression tests on coal samples subjected to four different soaking times in supercritical CO_(2).The paper analyzed the mechanical properties by examining the stress-strain curves of the coal samples and fitting physical and mechanical parameters.Subsequently,utilizing the energy calculation formula,the study derived the evolution characteristics of strain energy.Finally,based on the energy calculation formula,this study explored the evolution of energy by examining both the‘energy accumulation rate’and the‘energy dissipation rate’.The experimental setup primarily consists of a uniaxial testing system and a supercritical CO_(2)soaking device.The supercritical CO_(2)soaking device is comprised of a gas vacuum system,a gas pressurization system,and a gas heating and soaking system.The results indicate that as the soaking time in supercritical CO_(2)increases,both the compressive strength and elastic modulus of the coal gradually decrease.Based on the principles of energy calculation,as soaking time increases,a small amount of energy storage and dissipation characteristics is observed during the compaction stage of coal.The capacity to store elastic strain energy in the elastic phase gradually diminishes,while the proportion of dissipated energy within the total strain energy steadily increases during the plastic yield stage.The increase in dissipated energy during the post-peak residual strength stage leads to the penetration and expansion of macroscopic fractures within the coal.Building on this observation,the paper investigates the evolution mechanism of the energy accumulation rate and dissipation rate in coal samples.The research demonstrates that prior to reaching peak

关 键 词：安全工程 超临界CO_(2) 力学特性 能量演化 能量累积率 能量耗散率 

分 类 号：X936[环境科学与工程—安全科学]