阳泉新景矿高煤级煤的孔隙结构分形特征  

Fractal characteristics of pore structure in high rank coals from Xinjing coal mine, Yangquan

作　　者：毛潇潇[1] 赵迪斐[2,3] 杨玉娟[2,3] 卢晨刚 王雪莲[2] 郭英海[2,3] MAO Xiaoxiao;ZHAO Difei;YANG Yujuan;LU Chengang;WANG Xuelian;GUO Yinghai(College of Earth Science, China University of Petroleum (Beijing), Beijing 102249, China;School of Resources and Geosciences, China University of Mining and Technology, Xuzhou 221116, China;Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of Ministry of Education,China University of Mining and Technology, Xuzhou 221008, China)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国矿业大学(徐州)资源与地球科学学院,江苏徐州221116 [3]煤层气资源与成藏过程教育部重点实验室,江苏徐州221008

出　　处：《煤田地质与勘探》2017年第3期59-66,共8页Coal Geology & Exploration

基　　金：国家重点基础研究发展计划(973计划)课题(2012CB214702);2014年山西省煤基重点科技攻关项目(MQ201402);煤层气资源与成藏过程教育部重点实验室(中国矿业大学)开放基金资助项目(2015-007);中国矿业大学大学生创新训练项目(201415;201517)~~

摘　　要：分形理论是宏观上定量评价储层非均质性的有效手段。以阳泉新景矿高煤级煤样品压汞数据为基础,建立分形几何模型,定量描述了孔隙结构。实验结果表明:样品孔隙以纳米孔为主,孔径、比表面积及孔容也集中分布在纳米孔段。煤样孔径65 nm以上的孔隙具有显著的分形特征,分维值分布范围为2.89~2.99,体积增量呈现阶段式的变化,孔隙结构复杂;孔径65 nm以下孔隙几乎无分形特征,比表面积增量与孔径在对数坐标中呈线性关系;基于分形特征及分子运动规律,将储层孔隙以孔径65 nm为界划分为扩散孔和渗透孔2个大类6个小类。分维值与体积孔隙中值半径、总孔隙体积呈负相关,与孔径65 nm以上的孔隙体积、比表面积呈正相关,与孔隙度无相关性。分形分维值对储层结构具有较全面的表征能力,可以作为综合指标在煤储层孔隙研究中加以应用。Based on mercury intrusive data of high rank coal samples from Xinjing coal mine,fractal geometry model was built to describe the pore structure quantitatively.The results show that pores in coal samples mainly exist in nanoscale,the distribution of pore diameter,pore volume and specific surface area are also of nanoscale.The pore diameter over65nm are significantly fractal,the fractal dimension varies from2.89to2.99,and the variation of volume increment are phase-based,indicating complicated pore structure.There is a linear relationship between specific surface area increment and pore diameter below65nm(which are hardly fractal)in double logarithm coordinates,indicating a rather simple pore structure.Pores are classified into two major types:diffusion pores(<65nm)and seeping pore(>65nm)and6secondary types based on the fractal characteristics and laws of gas motion.Fractal dimensions are negatively related to median radius and total volume of pores,while positively related to pore volume and pore specific surface area in pores over65nm.The fractal dimension can be utilized in CBM reservoir exploration as a comprehensive index for its rather complete characterization ability.

关 键 词：压汞 高煤级煤 孔隙结构 分形维数 

分 类 号：P618.11[天文地球—矿床学]