羌塘盆地鲤鱼山—长梁山地区二叠—三叠系烃源岩特征及评价

发布时间：2018-06-03 08:24

本文选题：羌塘盆地 + 热觉茶卡组　；参考：《成都理工大学》2015年硕士论文

【摘要】：羌塘盆地油气资源丰富,但是前人对羌塘盆地油气的研究主要集中于三叠系和侏罗系地层,对羌塘盆地古生代烃源岩研究较少。本文运用岩石学、沉积学、油气有机地球化学方法,结合野外调查与室内工作,对比相关资料与学术研究成果,对北羌塘盆地鲤鱼山-长梁山地区上二叠统热觉茶卡组和上三叠统图中湖组实测地层剖面进行系统研究。通过野外剖面研究与室内显微镜下鉴定,结果表明,研究区内上二叠统热觉茶卡组是一套陆源碎屑复理石建造偶夹碳酸盐岩,其岩性主要为暗色页岩、泥页岩与岩屑砂岩、粉砂岩互层。上三叠统图中湖组为一套中层钙质砂岩夹厚-巨厚层火山角砾岩,局部有变质现象。运用沉积学对热觉茶卡组和图中湖组沉积相和沉积环境分析,表明研究区内上二叠统热觉茶卡组为咸水还原沉积环境,以浅海陆棚相为主。图中湖组沉积环境为宁静的半深海环境,以次深水盆地相为主。通过生物标志化合物分析,表明研究区内上二叠统热觉茶卡组有机质母源为低等浮游动物(细菌)、低等浮游植物(蓝藻、红藻等),并在晚二叠世海退后,接受了一定比例陆生植物来源。通过对烃源岩进行有机地球化学分析,表明在热觉茶卡组19件烃源岩样品中,有13件样品有机碳含量达到1.0%以上,属于好烃源岩,占68.4%。有6件样品含量介于0.6%-1.0%之间,属于中等烃源岩,在7件图中湖组烃源岩中,7件有机碳含量均小于0.4%,不是有效烃源岩。热觉茶卡组烃源岩样品大部分以腐泥组为主,其具有较好的生烃能力,其含量介于57%-78%之间,平均值为64%。镜质组生烃能力比腐泥组低,其百分含量基本为0。惰质组生烃能力弱,甚至一部分不生烃,其百分含量处于22%-43%,平均值为35.5%。利用类型指数Ti可知,热觉茶卡组以腐殖-腐泥型干酪根为主,占84.2%,腐泥-腐殖型干酪根占15.8%。根据热解参数分析,图中湖组有机质类型为腐殖型。热觉茶卡组烃源岩镜质体反射率皆大于1.3%,介于1.316-1.457%之间,均值为1.368%,热觉茶卡组样品Tmax值在323-522℃间,平均值为392℃,干酪根颜色均为棕褐色。表明有机质成熟度为高成熟度阶段,已达到生气阶段。而图中湖组的样品所测出的镜质体反射率,最高值为0.924%,最低值仅为0.845%,平均值为0.884%,其成熟度为成熟阶段,未达到生气阶段。通过对烃源岩综合评价,表明上二叠统热觉茶卡组烃源岩有良好的生烃潜力,并推测部分北羌塘盆地古生界地层烃源岩有较好的生烃前景。
[Abstract]:The Qiangtang basin is rich in oil and gas resources, but the previous studies of the Qiangtang Basin mainly focus on the Triassic and Jurassic strata, and there are few studies on the Paleozoic source rocks in the Qiangtang basin. In this paper, the petrology, sedimentology, organic geochemical methods of oil and gas, field investigation and indoor work were used to compare the relevant data and academic research results. A systematic study of the measured stratigraphic profiles of the upper two stack and the upper three superposition of the lake group of the upper Triassic in the North Qiangtang basin, the Chang Liang Shan area, has been systematically studied. The results show that the upper two superposition of the hot tea card group in the study area is a set of dual carbonate rocks of the terrestrial clastic flysch and its rock. The main features are dark shale, shale and lithic sandstone and siltstone interlayer. The upper three series of the lake group is a set of middle calcareous sandstone with thick and thick volcanic breccia, and partial metamorphic phenomenon. The sedimentary facies and sedimentary environment of the hot tea card group and the Tuzhong lake group are analyzed by sedimentology, indicating that the upper two stack hot tea cards in the study area are in the study area. The environment of saline water reduction and deposition is dominated by shallow sea shelf facies. The sedimentary environment of the lake group is tranquil semi deep sea environment, with the primary deep water basin facies. Through the analysis of biomarker compounds, it is indicated that the organic substance source of the upper two superposition hot tea group in the study area is lower zooplankton (bacteria), lower phytoplankton (cyanobacteria, red algae, etc.), and the lower phytoplankton (cyanobacteria, red algae, etc.) in the study area. After the Late Permian sea, a certain proportion of terrestrial plant source was accepted. Through the organic geochemical analysis of the source rocks, it was shown that of the 19 source rock samples of the hot tea card group, 13 samples had more than 1% organic carbon content, and 6 samples of 68.4%. were between the source rocks and the middle source rocks. In the 7 map, 7 organic carbon content is less than 0.4%, which is not the effective source rock. Most of the source rocks in the hot tea card group are mainly in the slime formation, which have good hydrocarbon generation ability, and their content is between 57%-78% and the average value of the 64%. vitrinite is lower than that of the rotten group, and the content is basically 0. inert. It is weak, even part of no hydrocarbon generation, its percentage is in 22%-43%, and the average value of 35.5%. utilization type index Ti shows that the hot tea card group is mainly humic - humid cheese root, 84.2%, and humic - humic kerogen accounts for 15.8%. according to the pyrolysis parameters. The reflectivity is more than 1.3%, which is between 1.316-1.457% and 1.368%. The Tmax value of the hot tea group is at 323-522 C, the average value is 392, and the color of the kerogen is brown. It shows that the maturity of the organic matter is high maturity stage, and it has reached the stage of life. The vitrinite reflectance measured by the sample in the lake group is 0.924. The minimum value is only 0.845%, the average value is 0.884%, and its maturity is the mature stage, which has not reached the stage of gas generation. Through the comprehensive evaluation of source rocks, it is shown that the upper two stack source rocks have good hydrocarbon generating potential, and the hydrocarbon source rocks of the Paleozoic strata in the northern Qiangtang basin have good hydrocarbon generation prospects.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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