孔隙压力对煤岩基质解吸变形影响的试验研究  

Experimental study of effect of pore pressure on desorption deformation of coal matrix

作　　者：吕祥锋[1] 潘一山[1] 刘建军[2] 唐巨鹏[1] 狄军贞[3] 

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000 [2]西南石油大学土木工程与建筑学院,成都610500 [3]辽宁工程技术大学建筑与工程学院,辽宁阜新123000

出　　处：《岩土力学》2010年第11期3447-3451,共5页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No50874082);国家自然科学基金青年项目(No10502023);国家重点基础研究发展规划(973计划)项目(No2010CB226803);辽宁省教育厅高等学校科技计划项目(No2008274)

摘　　要：煤层气开采过程中,伴随着煤层气不断地吸附、解吸和渗流,煤体产生变形,极易导致煤和瓦斯突出事故。以晋城天地王坡煤矿为例,通过实验室内试验,模拟煤层气在复杂地层漫长的形成和逐渐开采过程,得到了孔隙压力与解吸量、应变的变化关系,并拟合得出其相应关系表达式,揭示了一些新的规律:(1)初期解吸速度较快,解吸量随时间的增长而不断增加,后期解吸速度减缓,解吸量逐渐趋于稳定;(2)孔隙压力与解吸量、应变呈现抛物线曲线关系,随孔隙压力的升高,吸附和膨胀变形占主导,其值均在增大;(3)存在最小孔隙压力值,随孔隙压力的增大,解吸时间增长,孔隙压力越小,吸附解吸规律越不明显,对于晋城天地王坡煤矿3#煤样,该值在1.0MPa左右;(4)不同加载方式对解吸量和变形量影响较大,先部分加载吸附后全部载荷解吸结果同比加全部载荷吸附解吸结果高13%～77%。试验结果可为煤层气(CBM)抽放安全和煤与瓦斯突出防治提供理论依据。With the adsorption,desorption and seepage of coalbed methane（CBM）,coal mass deformation easily leads to coal-gas outburst in the process of production.Taking Tiandiwangpo Mine in Jincheng for example,the experiment of adsorption,desorption and seepage of coalbed methane（CBM） and deformation are simulated under complicated stresses condition.The relationships among pore pressure,desorption quantity and deformation are presented.The relationship expressions are studied.Some novel laws are obtained as follows.（1） At the beginning,desorption quantity increases rapidly over time;then it is stabilized latterly.（2） With the rising of pore pressure,the value of desorption quantity and deformation are increased;the desorption quantity and deformation are in parabolic curve relationship with pore pressure.（3） A minimal pore pressure exists;desorption time will increase with the increasing of pore pressure;the laws of desorption quantity and time will inconsistent when it is smaller than the minimal pore pressure.For the coal sample No.3,the minimal pore pressure is about 1.0 MPa.（4） Desorption quantity and coal mass deformation have a lot to do with loading methods;the result of loading methodⅡ is higher than loading methodⅠabout 13%-77%.The results provide a theoretical basis for security of coalbed methane（CBM） drainage and controlling of coal-gas outburst.

关 键 词：煤层气 解吸 变形 孔隙压力 

分 类 号：TD821[矿业工程—煤矿开采] O242[矿业工程—矿山开采]