被动大陆边缘构造演化对深水区烃源岩形成的控制

以世界被动大陆边缘含油气盆地构造演化、油气田资料为基础,采用地质综合分析方法,探讨了不同类型被动大陆边缘盆地在不同构造演化阶段深水区烃源岩的形成条件:开阔海型被动大陆边缘盆地群裂谷阶段发育大型局限湖盆,区域分布的厚层湖相富生油黑色泥页岩为主力烃源岩;边缘海型被动大陆边缘盆地群裂谷阶段发育受河流—波浪控制的大型三角洲,海陆过渡相富生气炭质泥页岩和煤系为主力烃源岩;被动大陆边缘阶段盆地群发生持续性海侵,在高水位体系域缺氧环境下的富有机质海相泥页岩为盆地重要的烃源岩。

Tectonic Evolution and Controls on Source Rock Development in Global Deep-water Area at Passive Continental Margin

Deep-water hydrocarbon in passive continental margins is one of the hot and bright spots of global petroleum exploration. There are two types of passive continental margins, i.e. open sea, and marginal sea. The tectonic evolution of passive continental margin had experienced pre-rift stage, syn-rift stage and passive continental margin stage. Based on the current situation of exploration and exploitation, and the latest oil and gas fields database of petroliferous basins in global deep-water area at passive continental margin, the genetic models of source rocks in two types of passive continental margins, and the different tectonic evolution stages were summarized. At open passive continental margin, large scale restricted lakes developed in deep-water area during syn-rift stage, oil-productive lacustrine black argillutite deposited regionally, being the major source rocks. At passive continental margins of marginal sea, larger scale river/wave dominated deltas developed in deep-water area during syn-rift stage, the major source rocks were transitional facies of argillutite and coal strata, controlling the gas distribution. During passive continental margin stage, continuous transgression happened in basins at passive continental margins, organic-rich marine argillutite deposited in anaerobic environment under high-water level system, forming major source rocks.