柴达木盆地团鱼山地区石门沟组煤与油页岩沉积环境  

Depositional Environment of Coal and Oil Shale of Middle Jurassic Shimengou Formation in Tuanyushan Area,Qaidam Basin

作　　者：陈玲玲 孟庆涛[1,2] 刘招君 徐银波[3] 孙平昌 王克兵 CHEN Lingling;MENG Qingtao;LIU Zhaojun;XU Yinbo;SUN Pingchang;WANG Kebing(School of Earth Sciences,Jilin University,Changchun,Jilin 130061,China;Jilin Key Laboratory for Oil Shale and Paragenetic Energy Minerals,Changchun,Jilin 130061,China;Oil and Gas Resource Survey Center,China Geological Survey,Beijing 100083,China)

机构地区：[1]吉林大学地球科学学院,长春130061 [2]吉林省油页岩与共生能源矿产重点实验室,长春130061 [3]中国地质调查局油气资源调查中心,北京100083

出　　处：《新疆石油地质》2018年第6期643-652,共10页Xinjiang Petroleum Geology

基　　金：国家自然科学基金(41872103);中国地质调查局油气基础性公益性地质调查项目(DD20160188-01)

摘　　要：柴达木盆地北缘团鱼山地区中侏罗统煤与油页岩广泛发育,但勘探程度较低,煤与油页岩沉积环境及成因研究较薄弱。利用团鱼山地区QD-2全取心井,通过岩石热解、有机碳、工业分析、GC和GC-MS等分析,开展研究区煤与油页岩有机地球化学特征及沉积环境分析。研究发现,研究区油页岩属于高灰分含量、低总有机碳含量、低—中含油率油页岩;而煤属于低灰分含量、高总有机碳含量、低变质的褐煤。煤与油页岩样品中均检测出正构烷烃、类异戊二烯烃、萜类、甾类及芳烃类化合物。在气相色谱图上,煤与油页岩正构烷烃呈前低后高单峰式分布;煤样品Pr/Ph高于油页岩,规则甾烷相对含量为C_(29)>>0>C_(28)>C_(27),芳烃类中,倍半萜类和二萜类化合物丰富。综合分析表明,研究区煤与油页岩均处于未成熟演化阶段,有机质来源以陆生裸子植物为主。油页岩形成于弱氧化的淡水浅湖环境,而煤则形成于氧化的沼泽环境,因此研究区煤与油页岩在有机质来源上无较大区别,而在沉积环境上差异较大。对比分析发现,有机质类型、来源及沉积环境的差异导致柴达木盆地团鱼山地区石门沟组含煤段与页岩段油页岩存在不同的赋存特征。The Middle Jurassic coal and oil shale are widely developed in the Tuanyushan area in the northern margin of the Qaidam basin,but the exploration level in the area is relatively low and the researches on the depositional environment and genesis of the coal and oil shale are relatively weak. Therefore, the paper uses the QD.2 full cored well in Tuanyushan area to study the organic geochemical charac.teristics and depositional environments of the coal and oil shale in the study area based on the analysis on rock pyrolysis, total organic car.bon, industrial quality parameter, gas chromatography and gas chromatography.mass spectrum. The study shows that the oil shale is charac.terized by high ash content, low organic carbon content and low-medium oil.bearing rate, and the coal belongs to low ash content, high or.ganic carbon content and low metamorphic grade lignite. N.alkanes, isoprenoid, terpenoid, steroid and aromatic hydrocarbons are detected in the coal and oil shale. On the gas chromatography, N.alkanes in both coal and oil shale are in single.peak distributions with the first low.er and later higher shape. The Pr/Ph value of coal is higher than that of oil shale, the relative content of the regular sterane is C29〉〉C28〉C27,abundant sesquiterpenoids and diterpenoids are detected in aromatic compounds. The comprehensive analysis shows that the coal and oil shale are at the immature stage of evolution and the organic matter mainly comes from terrestrial gymnosperms. The oil shale formed in a weak oxidation, fresh water and shallow lake environment and the coal formed in an oxidizing marsh environment. Therefore, as for the source of organic matters, there are no significant differences between the coal and oil shale, but their sedimentary environments are largely different. The comparison shows that the differences existed in the organic matter type, source and sedimentary environment result in the different occurrence characteristics of the oil shales in the coal.bearing intervals and in the shale intervals

关 键 词：柴达木盆地 团鱼山地区 中侏罗统 石门沟组 油页岩 煤 有机地球化学 水体环境 

分 类 号：TE112.113[石油与天然气工程—油气勘探]