低阶煤宏观煤岩组分孔隙结构特征研究  

Study on macroscopic pore structure characteristics of low-rank coal

作　　者：王传涛 党悦晨 高飞 马旭 庞香香 张壮壮 杨晓霞[1,3] 甄延忠 付峰 WANG Chuantao;DANG Yuechen;GAO Fei;MA Xu;PANG Xiangxiang;ZHANG Zhuangzhuang;YANG Xiaoxia;ZHEN Yanzhong;FU Feng(School of Chemistry and Chemical Engineering,Yan’an University;School of Petroleum Engineering and Environmental Engineering,Yan’an University;Research Institute of Comprehensive Energy Industry Technology,Yan’an University;Engineering Research Center of Oil and Gas Resource Efficient Development and Ecological Environment Protection of Shaanxi Universities,Yan’an 716000,China)

机构地区：[1]延安大学化学与化工学院 [2]延安大学石油工程与环境工程学院 [3]延能-延大综合能源技术研究院 [4]油气资源高效开发与生态环境保护陕西高校工程研究中心,陕西延安716000

出　　处：《延安大学学报（自然科学版）》2022年第3期38-45,共8页Journal of Yan'an University：Natural Science Edition

基　　金：陕西省科技厅区域创新能力引导计划项目(2022QFY07-06);陕西省自然科学基础研究计划项目(2021JQ-628);国家级大学生创新创业训练计划项目(202110719055)。

摘　　要：宏观煤岩组分孔隙发育规律研究对准确评价煤储层孔隙结构特征具有重要的现实意义。为得到低阶煤不同组分的孔裂隙发育特征,基于核磁共振技术研究了具有代表性宏观组分(镜煤和暗煤)的孔裂隙类型、孔隙连通性、孔隙度和孔径结构分布。研究发现,低阶煤饱和流体煤样核磁共振横向弛豫时间T_(2)谱3个谱峰分布于0.1~1 ms、10 ms和>100 ms处,分别对应于吸附孔、渗流孔和裂隙,孔裂隙类型以吸附孔为主;各煤样的T_(2)截止值和有效孔隙度均表现为暗煤大于镜煤,且煤岩有效孔隙度与渗透率呈线性相关关系;通过表面弛豫率和吸附峰T_(2)值得出各煤样孔径分布特征,孔径分布结果与液氮吸附测试结果吻合。结果表明,低阶暗煤孔裂隙发育程度优于镜煤,暗煤具有较大的孔径和更好的连通性,更有利于煤层气等流体的渗流和迁移。Study on pore development of macroscopic coal components has practical significance for evaluating pore structure characteristics of coal reservoir.In order to obtain the pore characteristics of different components of lowrank coal,pore types,pore connectivity,porosity and pore size distribution of vitrain and durain were studied based on nuclear magnetic resonance.It is found that three peaks of transverse relaxation time(T_(2))of saturated fluid samples located at 0.1-1 ms,10 ms and>100 ms,corresponding to adsorption pores,seepage pores and fractures,respectively,and the pore types are mainly adsorption pores.T_(2) cutoff values and producible porosity of each coal sample are calculated as both of them are bigger in durain than in vitrain with the producible porosity having a linear correlation with coal permeability.Pore size distribution characteristics obtained by surface relaxation rate and T_(2) of adsorption peak are consistent with that tested by liquid nitrogen adsorption.The results show that the pore development of durain is better than that of vitrain in low-rank coal.Durain has larger pore size and better connectivity,more conducive to the seepage and migration of coalbed methane and other fluids.

关 键 词：低阶煤 镜煤 暗煤 孔隙结构 核磁共振技术 

分 类 号：P618.11[天文地球—矿床学]