四川盆地西部二叠系多期台缘带油气勘探潜力

四川盆地西部二叠纪时期位于稳定克拉通边缘，受到海西运动、东吴运动和峨眉地裂运动的共同作用，发生构造-沉积分异。本文采用构造控盆、盆地控相、相控成藏要素组合的研究思路，在川西地区开展新一轮研究工作，揭示了二叠纪构造-沉积分异对油气成藏的控制作用，明确川西地区海相碳酸盐岩油气勘探潜力。盆地二叠纪以拉张伸展背景为主，总体呈现“南部隆升、西部裂陷、北部拉张”的沉积格局。二叠纪多期构造运动共同导致了川西地区一系列台内裂陷的形成，叠加二叠纪时期海平面变化，控制了栖霞至长兴期的多期台缘发育。川西北地区发育北东—南西向和北西—南东向两组断裂体系控制该区岩相古地理格局，其中龙门山断裂带主要控制了泥盆纪至二叠纪栖霞期沿上扬子台地西北缘发育台缘带，呈北东向展布。茅口至长兴期台缘带受克拉通边缘及台内裂陷共同控制，在川西地区呈北东向展布，梓潼—老关庙地区沿裂陷发育呈北西向展布，在剑阁一带，栖霞、茅口、吴家坪和长兴组多期台缘带叠置发育。川西地区二叠纪多期台缘控制了多层系优质滩相储层和礁储层叠置发育，是川西地区二叠系规模孔隙型储层发育的主控因素。多期古裂陷、多期台缘带和成藏期大型古隆起三元素耦合有利于油气规模聚集成...

Oil and gas exploration potential of the Permian multi-stage platform-margin zone,western Sichuan Basin.

Situated in stable cratonic margins during the Permian the western Sichuan Basin experienced tectonic-sedimentary differentiation under jointly the actions of the Hercynian movement, Dongwu movement and Emei rift. Adopting the research idea that tectonic movement controls basin, basin controls facies, facies control reservoir-forming elements,a new round of research is carried out in the western Sichuan Basin to investigate the control of petroleum accumulation by Permian tectonic-sedimentary differentiation and determine the exploration potential of marine carbonate rocks in the western Sichuan Basin. During the Permian, the Sichuan Basin is dominated by tensional/extensional tectonic activities and a general sedimentary pattern of “uplift in the south, rift in the west, and tension in the north” is revealed. The Permian multi-stage tectonic movements lead to the formation of a series of intra-platform rifts in western Sichuan, which, combined with the Permian sea-level change, control the multi-stage platform-margin development from the Qixia to Changxing formations. The NE-SW and NW-SE fault systems developed in the northwestern basin control the lithofacies paleo-geographic pattern of this area. Among them, the Longmenshan fault belt largely controls the development of platform margins N-E along the northwestern edge of the upper Yangtze platform from the Devonian to Permian Qixia periods. From the Maokou to Changxing periods, the platform margins—spreading N-E in the western Sichuan Basin and N-W along rifts in the Zitong-Laoguanmiao areas—are jointly controlled by cratonic margins and intra-platform rifts, and the multi-stage platform margins of the Qixia, Maokou, Wujiaping and Changxing formations are superimposed in the Jiange area. In the western Sichuan Basin, the Permian multi-stage platform margins control the superposition of multi-layer, high-quality beach facies reservoirs and reef reservoirs, which is the main factor controlling the development of large-scale Permian porous reservoirs in this area. The coupling of multi-stage paleo-rift depression, multi-stage platform-margin zones and large-scale paleo-uplift in the reservoir-forming stage is conducive to the large-scale oil and gas accumulation. Vertically superimposed and spreading N-W over a wide range the multi-layer platform margins of western Sichuan possess trillion-ton petroleum resource potential and are an important replacement exploration target for marine carbonate rocks in the Sichuan Basin.