南祁连盆地侏罗系聚煤模式与煤储层特征研究

发布时间：2018-05-08 08:09

本文选题：南祁连盆地 + 侏罗系　；参考：《成都理工大学》2017年硕士论文

【摘要】：南祁连盆地位于青藏高原东北缘,北侧毗邻中祁连山体和北祁连山体,南侧毗邻宗务隆山-青海南山。南祁连地区一直被称为经典地区,其丰富的地质现象和良好的出露条件为我国造山带研究提供坚实的物质基础。鉴于南祁连盆地的实际地质情况,从煤层气富集成藏核心内容出发,对盆地主力煤层的聚煤模式、煤层发育与展布情况及岩相古地理进行了深入分析和研究,明确了南祁连盆地煤层气聚煤模式和储层特征。研究结果表明,侏罗系木里组和江仓组是南祁连盆地最主要的含煤层系。辫状河-辫状河三角洲沉积体系主要发育于中侏罗统木里组,辫状河三角洲-湖泊沉积体系主要发育于中侏罗统江仓组,在辫状河三角洲沉积体系中多发育厚煤层,且研究区东北部托莱山和南部大通山地区提供主要物源,主要的聚煤环境位于三角洲平原泥炭沼泽,并指出以三角洲平原沼泽是最好的成煤环境。地质构造、煤层顶底板岩性、煤层厚度、地质条件以及煤层气组成等因素控制着侏罗系煤层气成藏,其中煤层气藏的形态受构造控制,煤层含气量被煤层顶底板所制约。煤质有机质具备较强的生气能力,东南部侏罗系有机质生气潜力较大,以裂解气为主。从镜质组反射率及煤演化类型特征可以看出,西北部煤热演化成度偏低,生气潜力偏小,以长焰煤和气煤为主;东南部煤热演化成度高,生气潜力大,以焦煤和瘦煤为主;中部煤热演化成度适中,生气潜力一般,以肥煤为主。
[Abstract]:The South Qilian Basin is located on the northeast margin of the Qinghai-Xizang Plateau, adjacent to the Middle Qilian Mountains and the North Qilian Mountains to the north, and adjacent to the Zongwu Longshan Mountains to the Southern Qinghai Mountains in the south. The South Qilian region has been called the classical area. Its rich geological phenomena and good outcrop conditions provide a solid material basis for the study of orogenic belts in China. In view of the actual geological conditions of the South Qilian Basin, starting from the core contents of the coalbed methane rich integrated reservoir, the coal accumulation model, the development and distribution of the coal seam and the lithofacies and paleogeography of the main coal seams in the basin are deeply analyzed and studied. The coal accumulation model and reservoir characteristics of coalbed methane in South Qilian Basin are defined. The results show that Jurassic Muli formation and Jiangcang formation are the most important coal-bearing systems in South Qilian Basin. The braided river-braided river delta sedimentary system is mainly developed in the Muli formation of the Middle Jurassic, the braided river delta-lake sedimentary system is mainly developed in the Jiangchang formation of the Middle Jurassic, and the thick coal seams are mostly developed in the braided river delta sedimentary system. In the northeast of the study area Tulai Mountain and the southern Datong Mountain area, the main coal accumulation environment is located in the peat swamps in the delta plain, and it is pointed out that the delta plain swamp is the best coal-forming environment. Geological structure, seam roof and floor slate, coal seam thickness, geological conditions and coalbed methane composition control Jurassic coalbed methane reservoir, in which coalbed methane reservoir morphology is controlled by structure, and coal seam gas content is restricted by coal seam roof and floor. Coal organic matter has strong generating ability, and Jurassic organic matter in southeastern China has a great potential to generate gas, mainly pyrolysis gas. From the characteristics of vitrinite reflectance and coal evolution type, it can be seen that the thermal evolution of coal in the northwest is low, the potential of generation is small, and the coal thermal evolution is mainly long flame coal and gas coal, while in the southeast, the thermal evolution of coal is high, the generation potential is large, and the coal thermal evolution is mainly coking coal and lean coal. The thermal evolution of central coal is moderate, the potential of gas generation is general, and fat coal is the main source.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.1

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