准南中低阶煤孔径结构全孔径定量综合表征  

Quantitative and comprehensive characterization of full pore size in medium and low rank coal in southern margin of Junggar basin

作　　者：卢杰林 傅雪海[1] 康俊强 LU Jielin;FU Xuehai;KANG Junqiang(Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process (Ministry of Education), China University of Mining and Technology, Xuzhou, Jiangsu 221116, China)

机构地区：[1]中国矿业大学煤层气资源与成藏过程教育部重点实验室,江苏徐州221116

出　　处：《中国科技论文》2022年第1期62-71,共10页China Sciencepaper

基　　金：国家自然科学基金资助项目(42072190)。

摘　　要：为研究准南地区中低阶煤孔径结构特征,采集6块中低阶煤样,采用高压压汞、低温液氮吸附和二氧化碳吸附实验分别测试不同煤样的孔径结构,研究不同测试方法之间的衔接孔径,并对准南地区中低阶煤进行全孔径表征。结果表明,液氮吸附法与高压压汞法平滑过渡衔接应满足阶段体积增量相等,且阶段体积增量与孔径的一阶导数相等,即dV_(Hg)/dD=dV_(N2)/dD。准南地区中低阶煤孔径结构<1.47 nm用二氧化碳吸附法表征,1.47~40 nm用低温液氮吸附法表征,>40 nm用高压压汞法表征。全孔径结构的联合表征结果表明,阶段孔体积的大孔>微孔>介孔,阶段比表面积的微孔>大孔>介孔。准南中低阶煤的惰质组含量与孔比表面积呈较好的正相关关系,对孔隙比表面积有重要贡献;镜质组含量与孔比表面积呈较强的负相关关系,对比表面积贡献较弱。研究结果对中低阶储层煤层气的赋存和运移具有理论意义,对中低阶储层煤层气的开发也有指导作用。To study the pore structure characteristics of medium and low rank coal in southern margin of Junggar basin,six coal samples of medium and low rank were collected from the southern margin of Junggar basin.The pore size structures of coal samples were tested by high pressure mercury injection,low temperature nitrogen adsorption and carbon dioxide adsorption experiments.The connecting pore diameters in different testing methods were studied and the full pore size characterization of medium and low rank coal in Zhunnan area was carried out.The results show that the smooth transition connection between liquid nitrogen adsorption and high pressure mercury injection shall satisfy that the volume increment of the stage is equal,and the first derivative of the mercury input in the stage is equal to the first derivative of the pore diameter,that is,(dV_(Hg)/dD)=(dV_(N2)/dD).The pore size smaller than 1.47 nm was characterized by carbon dioxide adsorption method,the pore size between 1.47~40 nm was characterized by low temperature nitrogen adsorption method and the pore size larger than 40 nm was characterized by high pressure mercury injection method.Comprehensive characterization of full pore size shows the distribution of pore volume has the rule that macroporous is larger than microporous while microporous is larger than mesoporous,and the distribution of pore specific surface area has the rule that microporous is larger than macroporous while macroporous is larger than mesoporous.There is a good positive correlation between inertinite content and pore specific surface area,which makes an important contribution to pore specific surface area,and a strong negative correlation between vitrinite content and pore specific surface area.The contribution of contrast surface area is weak.The results have theoretical significance to the occurrence and migration of coalbed methane in low-rank coal reservoirs,and can also guide the development of coalbed methane in low-rank reservoirs.

关 键 词：孔径结构 全孔径表征 高压压汞 低温液氮吸附 二氧化碳吸附 

分 类 号：P618.11[天文地球—矿床学]