鸡西盆地城子河组沉积相与煤层气勘探潜力研究

发布时间：2018-05-17 06:36

本文选题：鸡西盆地 + 城子河组　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：鸡西盆地城子河组主要发育三角洲相和湖泊相,部分区域发育河流相。城子河组沉积早期,盆地北部三角洲和南部三角洲连成一个整体,盆地东部为滨浅湖、深湖-半深湖亚相;城子河组沉积中期,南北两个三角洲主体分离,盆地中部发育湖泊相而盆地东部一定区域内发育较大规模湖湾沼泽,盆地西北和东南边缘发育冲积平原;城子河组沉积晚期,南北两个三角洲的规模进一步扩大,另外盆地冲积平原的规模也随之扩大,而盆地中部的湖泊相规模缩小。鸡西盆地城子河组沉积时期有利的成煤环境为南北两个三角洲平原亚相和部分时期发育的湖湾沼泽亚相。鸡西盆地城子河组主要煤层顶板岩性组合类型可以分为三种:泥质岩类优势型顶板、坚硬岩类优势型顶板和破碎型顶板,其中泥质岩类优势型顶板对于煤层气的富集和保存最为有利。盆地大部分区域发育沉积物较细的沉积相类型从而在盆地大部分区域形成泥质岩类优势型顶板盖层,坚硬岩类优势型顶板只发育在盆地边缘少部分区域。由此可见鸡西盆地的煤层气勘探潜力较大。鸡西盆地城子河组主要煤层显微煤岩组分以镜质组为主,主要煤层宏观煤岩类型为光亮煤,属高灰分低硫煤。主要煤层煤阶为气煤、焦煤。盆地煤层的变质程度较高,具有良好的煤层气生成潜力。鸡西盆地北部鸡东凹陷和南部穆棱凹陷地质构造以挤压型大型复向斜为主,对于煤层气的富集和保存是有利的。盆地煤层含气量具有随煤层埋深的增加而增高,盆地北带鸡东凹陷煤层比南带穆棱凹陷煤层埋深大。鸡东凹陷和穆棱凹陷水文条件相对简单,主要通过水力封堵和水力封闭控气作用对煤层气富集产生有利影响。盆地南部敦密断裂带附近断裂发育,地层富水性强并与煤层水力联系较好,地下水在循环过程中导致煤层气的逸散。综合各种地质条件划分出鸡西盆地的2个煤层气有利区带:兰岭-东海煤层气有利区,合作煤层气有利区。
[Abstract]:Delta facies and lacustrine facies are mainly developed in Chengzihe formation, Jixi Basin, and fluvial facies are developed in some regions. In the early sedimentary period of Chengzihe formation, the delta in the north and south of the basin formed a whole, and in the eastern part of the basin there was a littoral shallow lake, deep lacustrine and semi-deep lacustrine subfacies, and in the middle depositional period of Chengzihe formation, the two deltas were separated from each other. The lacustrine facies developed in the central part of the basin and the large scale lake bay swamps developed in the eastern part of the basin, the alluvial plains developed in the northwest and southeast margin of the basin, and the scale of the two deltas expanded in the late Chengzihe formation. In addition, the scale of basin alluvial plain also expands, and the scale of lacustrine facies in the middle of basin is reduced. The favorable coal-forming environment of Chengzihe formation in Jixi Basin is the subfacies of the delta plain in the north and south and the subfacies of the swamp in the lake bay developed in part of the period. The main coal seam roof lithologic assemblages of Chengzihe formation in Jixi Basin can be divided into three types: mudstone dominant roof, hard rock dominant roof and broken roof. The dominant roof of argillaceous rock is the most favorable for the enrichment and preservation of coalbed methane. In most areas of the basin, the sedimentary facies types of sediment are relatively fine, so that the mudstone dominant roof caprocks are formed in most areas of the basin, while the hard rock dominant roof is only developed in a few areas on the margin of the basin. It can be seen that the exploration potential of coalbed methane in Jixi Basin is great. The main coal micronites in Chengzihe formation of Jixi Basin are vitrinite, and the main coal beds are bright coal with high ash content and low sulfur content. The coal rank of main coal seam is gas coal and coking coal. The metamorphism of coal beds in the basin is relatively high and has a good potential for coalbed methane generation. The geological structure of Jidong Sag and Muling Sag in the north of Jixi Basin is mainly compression-type and large compound oblique, which is favorable for the enrichment and preservation of coalbed methane. The gas content of the coal bed in the basin increases with the increase of the depth of the coal bed, and the coal bed in the Jidong depression of the northern belt of the basin is larger than that in the Muling sag in the south belt of the basin. The hydrological conditions of Jidong sag and Muling sag are relatively simple. The enrichment of coalbed methane is mainly influenced by hydraulic plugging and controlling gas by hydraulic sealing. In the southern part of the basin, the faults are developed near the Dumi fault zone, the formation is rich in water and has good hydraulic connection with the coal seam, and the groundwater causes the coalbed methane to dissipate during the circulation process. According to various geological conditions, two favorable zones of coalbed methane are divided into two favorable zones in Jixi basin: the favorable zone of Lanling to East China Sea, and the favorable zone of cooperative coalbed methane.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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