鄂尔多斯盆地侏罗系延安组煤岩特征及其主控因素分析  

Coal macerals characteristics and the main control factor of Jurassic Yan'an Formation in Ordos basin

作　　者：杜芳鹏 刘池洋[2] 宁树正 乔军伟 赵晓辰 贺小元 李亚婷[1] 张萍[1] 杨剑羽 王浩杰 王子策 DU Fangpeng;LIU Chiyang;NING Shuzheng;QIAO Junwei;ZHAO Xiaochen;HE Xiaoyuan;LI Yating;ZHANG Ping;YANG Jianyu;WANG Haojie;WANG Zice(School of Petroleum Engineering and Environmental Engineering,Yan'an University,Yan'an,Shaanxi 716000,China;State Key Laboratory for Continental Dynamics/Department of Geology,Northwest University,Xi'an,Shaanxi 710069,China;General Prospecting Institute of China National Administration of Coal Geology,Beijing 100039,China;College of Geology and Environment,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China)

机构地区：[1]延安大学石油工程与环境工程学院,陕西延安716000 [2]西北大学地质学系,大陆动力学国家重点实验室,陕西西安710069 [3]中国煤炭地质总局勘查研究总院,北京100039 [4]西安科技大学地质与环境学院,陕西西安710054

出　　处：《地质学报》2024年第12期3751-3772,共22页Acta Geologica Sinica

基　　金：陕西省自然科学基础研究计划项目(编号2024JC-YBMS-222);中国地质调查局地质调查项目(编号DD20160187);延安市2023年科技计划项目(编号2023-CYL-151)联合资助的成果。

摘　　要：盆地级宏观视角的煤岩特征研究,有助于深化盆地控煤理论、全面认识盆地演化过程,同时也对于煤层生物气、直接液化用煤、富油煤等资源的分布预测及整体利用规划具有参考价值。鄂尔多斯盆地侏罗系延安组煤炭资源丰富,经历了数十载的勘查和研究,积累了丰富的煤岩资料,可供开展盆地视角的煤岩特征研究。系统收集、整理了前人鄂尔多斯盆地延安组煤岩显微组分数据,并于宁东煤田、陕北侏罗纪煤田、黄陇侏罗纪煤田分别采取了代表性煤岩样品,开展了煤岩研究和元素地球化学分析。研究结果显示,鄂尔多斯盆地侏罗系延安组煤层具有富惰质组的特征,惰质组含量与镜质组含量相当,镜质组以基质镜质体为主,含少量结构镜质体、均质镜质体和团块镜质体;惰质组以半丝质体为主,含少量氧化丝质体、粗粒体和碎屑惰质体;壳质组以小孢子体为主,还有树脂体、角质体和木栓质体。煤岩组分在平面上呈环带状分布特征,从盆地边缘向盆地中心惰质组含量降低、镜质组含量增高。延安组各煤层呈中部煤层惰质组含量较低,向上部煤层和下部煤层惰质组含量增高。对比分析表明鄂尔多斯盆地延安组为典型的坳陷型盆地环带状聚煤模式,聚煤中心与沉积中心完全分离;远离盆地中心方向,泥炭遭受的氧化时间、氧化范围和氧化强度均逐渐增大,导致惰质组含量增高;反之,靠近湖盆方向惰质组含量减少。The study of coal maceral from a basin-level perspective contributes to a deeper understanding of basin coal-forming mechanisms and overall basin evolution.Additionally,it aids in predicting resource distribution and planning the utilization of resources such as coalbed methane,coal direct liquefaction,and tar-rich coals.The Yan'an Formation in the Ordos basin is renowned for its abundant coal resources.Decades of exploration and research have yielded a wealth of coal maceral data,providing a solid foundation for basin-wide coal maceral studies.This research systematically collected and analyzed coal maceral data from the Yan'an Formation across the entire basin.Besides,detailed layered coal samples were obtained for vertical maceral analysis from various mines in the Ningdong,Shaanbei Jurassic,and Huanglong Jurassic coalfields.Both the collected maceral data and data from the layered coal samples show that the Yan'an Formation coals are characterized by the enrichment of inertinite,which is nearly equivalent to the vitrinite content.Vitrinite is mainly composed of collodertrinite,collotelinite,and telinite,with variations of homogeneous vitrinite and clustered vitrinite.The inertinite group consists mainly of semifusinite,fusinite,funginite,macrinite,micrinite,and inertodetrinite.The liptinite group is primarily composed of sporinite,cutinite,resinite,bituminite,and exsudatinite.Coal macerals exhibit a ring-shaped distribution pattern on the plane,with inertinite content decreasing and vitrinite content increasing from the basin periphery to the center.Vertically,inertinite content in the middle coal seam of the Yan'an Formation is relatively lower compared to the upper and lower coal seams.This pattern suggests a ring-shaped coal accumulation model controlling the accumulation of Yan'an coals,with the coal accumulation center completely separated from the sedimentary center.Coal peats away from the basin center experienced more oxidation,leading to an increase in the inertinite content,while the inertinite cont

关 键 词：显微煤岩组分 坳陷型盆地 鄂尔多斯盆地 延安组 富惰质组煤 

分 类 号：P618.11[天文地球—矿床学]