超临界CO_(2)脉动作用对低阶煤微观-宏观结构损伤演化特征  

Microscopical and macroscopic structural damage evolution of low-rank coal by supercritical CO_(2) pulsation treatment

作　　者：刘佳佳[1,2,3,4] 李元隆 高建良 王丹[1,3,4] 张云龙 LIU Jiajia;LI Yuanong;GAO Jianiang;WANG Dan;ZHANG Yunong(School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo 454003,China;State Key Laboratory of Mining Response and Dis-aster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan 232001,China;Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Henan Polytechnic University,Jiaozuo 454003,China;Henan Provincial Key Laboratory of Gas Geology and Gas Control-Provincial and Ministry of State Key Laboratory Breeding Base,Henan Polytechnic University,Jiaozuo 454003,China)

机构地区：[1]河南理工大学安全科学与工程学院,河南焦作454003 [2]安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室,安徽淮南232001 [3]河南理工大学煤炭安全生产与清洁高效利用省部共建协同创新中心,河南焦作454003 [4]河南理工大学河南省瓦斯地质与瓦斯治理重点实验室—省部共建国家重点实验室培育基地,河南焦作454003

出　　处：《煤炭科学技术》2025年第2期190-199,共10页Coal Science and Technology

基　　金：国家自然科学基金资助项目(52074106);河南省自然科学基金资助项目(232300421061);中国博士后科学基金资助项目(2024M750803)。

摘　　要：为了明晰超临界CO_(2)脉动作用对低阶煤的作用效果及机理,采集新疆艾维尔沟矿深部低阶煤作为试验对象,通过自主搭建的超临界CO_(2)脉动致裂试验系统开展试验研究,对脉动作用前后的煤样分别进行XRD、FTIR、低温液氮吸附试验、低场核磁共振及单轴压缩试验测定,量化分析超临界CO_(2)脉动作用前后煤体的微观结构、孔隙结构及力学特性变化。结果表明:超临界CO_(2)脉动作用后,煤中方解石和黏土矿物的质量分数增加,黏土矿物质量分数的变化主要受氨伊利石增加的影响,煤中各有机官能团峰值均呈现不同程度的降低,超临界CO_(2)对有机物的萃取作用效果明显,脉动作用后煤体的微晶结构受到损伤,晶体层片间距增加了0.002 9 nm,煤体结构趋于松散;对比超临界CO_(2)脉动作用前,作用后煤样XJ-A、XJ-B有效孔隙率分别提高了66.7%、128.6%,煤体内部孔隙连通性增强,脉动作用对微小孔及中孔的改造作用更明显;超临界CO_(2)脉动作用后煤的力学特性显著劣化,单轴抗压强度和弹性模量分别降低54.73%和59.82%,声发射振铃计数和累积能量均大幅降低,振铃计数峰值降至作用前51%,煤样内部颗粒黏聚力降低,累积能量降低了62%。综上,超临界CO_(2)脉动作用能够显著破坏低阶煤的微观-宏观结构,对深部低阶煤储层致裂增透、煤层气抽采具有重要意义。In order to clarify the effect and mechanism of supercritical CO_(2) pulsation on low-rank coal,deep low-rank coal from the Aiwi-ergou Mine in Xinjiang was collected as the experimental object.Experimental research was carried out through an independently built su-percritical CO_(2) pulsation fracturing experimental system.Before and after the pulsation,the coal samples were respectively measured by XRD,FTIR,low-temperature liquid nitrogen adsorption test,low-field nuclear magnetic resonance,and uniaxial compression test.The changes in the microscopic structure,pore structure,and mechanical properties of the coal before and after the supercritical CO_(2) pulsation were quantitatively analyzed.The results show that after the supercritical CO_(2) pulsation,the mass fractions of calcite and clay minerals in the coal increase.The change in the mass fraction of clay minerals is mainly affected by the increase of ammoniated illite.The peak values of various organic functional groups in the coal show different degrees of decrease,indicating that the extraction effect of supercritical CO_(2) on organic matter is obvious.After the pulsation,the microcrystalline structure of the coal is damaged,the crystal lamellar spacing in-creases by 0.0029 nm,and the coal structure tends to be loose.Compared with before the supercritical CO_(2) pulsation,the effective porosit-ies of coal samples XJ-A and XJ-B increase by 66.7%and 128.6%respectively after the pulsation.The connectivity of pores inside the coal is enhanced,and the pulsation has a more obvious effect on the modification of micropores and mesopores.After the supercritical CO_(2) pulsation,the mechanical properties of the coal deteriorate significantly.The uniaxial compressive strength and elastic modulus decrease by 54.73%and 59.82%respectively.The acoustic emission ring-down count and cumulative energy are both greatly reduced.The peak value of the ring-down count drops to 51%of that before the pulsation,the cohesion of internal particles in the coal sample decreases,and

关 键 词：超临界CO_(2) 脉动致裂 微观结构 孔隙 力学特性 

分 类 号：TD712[矿业工程—矿井通风与安全]