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上扬子地台是我国南方的海相油气富集区,其周缘地区分别处于不同的构造带中,构造变形差异显著,致使海相油气的盖层和保存条件各异.在揭示上扬子三江地区中新生代构造变形特点的基础上,结合岩相古地理和油气成藏要素的演化,探讨后期构造活动对海相油气分布和高原低熟油气形成的控制.研究认为,印支运动的推覆挤压破坏了早期的海相生储盖组合,同时也导致山前带挠曲下陷,发育新的成藏组合.燕山运动期间,在稳定的盆地裂陷过程中沉积了一套区域性海泛湖相泥岩,既是优质源岩,也是有效的区域盖层.在白垩纪至古近纪的盆地萎缩过程中,发育了区内最重要的景星组(K1j)储层,以及古近系膏泥岩层,该套地区性盖层对高-过成熟的裂解气有重要保存意义.新近纪以来,强烈的走滑断陷和高原隆升过程对海相油气的后期保存十分不利,同时,控制了一系列小型山间断陷盆地的形成,这些盆地陆源和水生有机质都佷丰富,在低热演化阶段,源岩遭受微生物降解,形成未熟-低熟油气,尽管该类油气资源有限,但对于青藏高原低演化油气的勘探有所借鉴.
The upper Yangtze platform is a marine oil and gas accumulation area in the south of China. Its peripheral areas are located in different tectonic belts respectively, and the structural deformation is significantly different, resulting in different caprock and preservation conditions of the marine oil and gas. Based on the tectonic deformation characteristics of Mesozoic and Cenozoic and the evolution of lithofacies palaeogeography and hydrocarbon accumulation elements, the paper discusses the post-tectonic activities controlling the distribution of marine oil and gas and the formation of low-mature oil and gas in the plateau. During the Yanshan movement, a set of regional sea-pan-lake was deposited in the process of stable basin rifting, which resulted in the collapse of the foreland belt. Phase mudstone is not only a good source rock but also an effective regional cap rock. During the Cretaceous to Paleogene basin atrophy, the most important Jingxing Formation (K1j) reservoir in the area and the Paleogene limestone and mudstone Layer, this set of regional cap rocks has important preservation significance for the over-mature pyrolysis gas.After the Neogene, strong strike-slip faulting and uplift of the plateau are very unfavorable to the post-preservation of marine oil and gas, and at the same time, A series of small mountains The terrigenous and aquatic organic matter is abundant in these basins. During the low thermal evolution stage, the source rocks are subject to microbial degradation to form immature-low mature oil and gas. Although these resources are limited, the exploration of low-grade hydrocarbon in the Qinghai-Tibet Plateau Learn from