西山煤田古交矿区不同深度煤储层CH4吸附解吸特征  

Adsorption and Desorption Characteristics of CH on Coal with Different Depths in Gujiao Mining Area of Xishan Coalfield

作　　者：周家锐 宋晓夏[1,2] 李伟 ZHOU Jiarui;SONG Xiaoxia;LI Wei(College of Mining Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Shanxi Key Laboratory of Coal and Coal Measure Gas Geology,Taiyuan 030024,China;Institute of Unconventional Oil&Gas,Northeast Petroleum University,Daqing 163318,China)

机构地区：[1]太原理工大学矿业工程学院,山西太原030024 [2]煤与煤系气地质山西省重点实验室,山西太原030024 [3]东北石油大学非常规油气研究院,黑龙江大庆163318

出　　处：《煤矿安全》2020年第12期1-7,共7页Safety in Coal Mines

基　　金：国家自然科学基金青年科学基金资助项目(41902176);山西省煤层气联合研究基金资助项目(2014012004)。

摘　　要：不同赋存深度的煤储层CH4吸附解吸特征是影响西山煤田古交矿区煤层气开发效果和产能分布的重要因素。以山西组2号煤层和太原组8号煤层为研究对象,分析了温度40℃和压力8 MPa条件下干燥煤CH4吸附解吸特征随埋深的变化规律,基于纳米孔隙分布特征探讨了埋深对CH4吸附解吸的控制机制。研究表明:随着埋深的增加,煤级升高,微孔增加,导致CH4吸附能力增大,而中大孔对不同深度煤储层CH4吸附的影响微弱;高压是埋深作用下利于CH4吸附的另一原因;煤层埋藏越深,CH4吸附解吸迟滞程度越高;小于0.7 nm超微孔隙含量的增多及其诱导的微孔非均质性的增强是CH4吸附滞后现象随埋深增加而显著的原因。The adsorption and desorption characteristics of CH4 on coal with different depths are significant of development effect and productivity distribution of coalbed methane in Gujiao Mining Area,Xishan Coalfield.Thus,as the No.2 coal seam from Shanxi Formation and the No.8 coal seam from Taiyuan Formation were sampled,the change of adsorption and desorption characteristics of CH4 on dry coal under the conditions of temperature of 40℃and pressure of 8 MPa with the increasing buried depth was analyzed.The control mechanisms of buried depth on CH4 adsorption and desorption were discussed based on the characteristics of nano-pores distribution.The results show that,with the increase of burial depth,both the coal rank and micropores increase,resulting in the increase of CH4 adsorption capacity.However,the influence of mesopores and macropores on the adsorption of CH4 in coal reservoirs with different depths is weak.The buried depth dependent high pressure is another reason favoring for CH4 adsorption.The deeper the coal seam is buried,the higher the degree of hysteresis of CH4 adsorption and desorption.The increasing in ultra-pore with size less than 0.7 nm and the induced enhancement of micropore heterogeneity are reasons for the significant CH4 adsorption hysteresis with the increasing burial depth.

关 键 词：低温氩气吸附 二氧化碳吸附 孔隙特征 煤层气 吸附解吸 

分 类 号：TD712[矿业工程—矿井通风与安全]