中煤阶煤岩控制下的煤储层孔裂隙结构特征——以柳林矿区为例  

Pore and fissure structure characteristics of medium rank coal under the control of coal petrology:taking Liulin mining area as the example

作　　者：李玲[1,2] 汤达祯[2] 许浩[2] 孟艳军[2] 房媛[2] 唐淑玲[2] 

机构地区：[1]大庆油田有限责任公司,黑龙江大庆163002 [2]中国地质大学(北京)能源学院,北京100083

出　　处：《中国科技论文》2015年第9期1058-1065,共8页China Sciencepaper

基　　金：高等学校博士学科点专项科研基金资助项目(20130022110010);国家自然科学基金资助项目(41272175)

摘　　要：为了探讨煤岩类型和煤储层孔隙结构的耦合关系,建立了煤层层内非均质模型,采用压汞、液氮、CT等实验测试手段和分形数学理论,根据实验得到的各孔径段孔隙含量、视孔隙率、体积中值半径、退汞效率、BET比表面积、BJH总孔容、平均孔径等参数的均值来研究光亮煤、半亮煤、半暗煤和暗淡煤储层物性差异,结合CT三维空间建模,分析了不同煤岩类型煤储层孔隙结构特征与差异性。结果表明:光亮煤微裂隙发育,连通性好,有利于煤层气的解吸、扩散和渗流,为煤层气勘探开发的有利储层;半亮煤孔隙连通性好,较有利于煤层气解吸、扩散和渗流,同样为有利储层;半暗煤孔径分布较均衡,半封闭-开放孔发育,较有利于煤层气富集和渗流,为煤层气勘探开发的中等储层;暗淡煤微小孔含量最低,空间呈点状分布,矿物含量高,裂隙不发育,对于煤层气的渗流和储集均不利。原生结构煤为主的矿区煤层气开发应首选光亮煤发育带,其次为半亮煤和半暗煤发育带。该结论可为煤层气开采过程中层间非均质性提供指导依据。To study the coupling relationship between macro-lithotypeand pore structure of the coal and establish the heteroge-neousmodel within coal layers,the experimental testing methods (including mercury injection,liquid nitrogen,computed tomo-graphy (CT))and the fractal mathematical theory are used to analyze the differences of reservoir physical properties among bright,semibright,semidull and dull coal basedon the experimentally obtained mean parameters such as the aperture porosity content,apparent porosity,median radius,mercury withdrawal efficiency,BET specific surface,BJH total pore volume,and av-erage pore diameter in combination with three-dimensional (3D)space construction.The research reveals that fissures of the bright coal are most developed and well connected,which is favorable reservoir for coalbed methane (CBM)exploration and de-velopment.Good pore connectivity of the semibright coal makes it also favorable for CBM exploration and development.The homogeneous pore distribution of each stage and developed semi-open pore makes the semidull coal less conducive to CBM enrich-ment and seepage.In the dull coal,the lowest content of micro pores,scattering distribution in 3D space,high mineral content, and not developed fissures all make it unfavourable to the CBM reservoir accumulation and seepage.Therefore,in the primary coal and CBD development,the bright coal should be the first choice,and then the semibright and semidull coal developing zones, the dull coal is the worst.This conclusion can provide guidance for interlayer heterogeneity during CBM exploitation.

关 键 词：中煤阶 煤岩类型 孔隙结构特征 层内非均质性 

分 类 号：P618.13[天文地球—矿床学]