不整合构造对油气的控制作用

The Controlling Role of Unconformity to Oil and Gas

地层不整合对油气成藏具有重要作用,不整合面上下形成的油气藏均与不整合面有关。论述了不整合面结构、类型以及不整合面上下岩性配置与油气成藏的关系,得出不整合与油气成藏的关系主要表现为不整合面上、下发育的储集砂体不仅可以为油气提供良好的侧向运移通道,而且可以把不同时代的储积层、断裂等连接起来组成区域性的运移通道网络组,不整合面之上的风化粘土层还可形成良好的盖层。构造不整合可以使早先形成的油气藏的盖层被剥蚀冲刷或者对储层进行改造,导致不整合形成的油气藏发生各种稠变作用或者散失,而稠变后的原油,对晚期的油气成藏具有封堵作用。

Stratigraphic unconformity have an important effect on oil and gas accumulation, and the formation of oil- gas pools located in the up and down of unconformity surface is related to the surface. This paper discusses the structure and types of unconformity surface, and the relationship between lithology configuration of the up and down of unconformity surface and formation of oil- gas pools. What＇s more, the relationship between them mainly displays in the reservoir sandbody of the up and down of unconformity surface being as oil- gas migration channel, forming unconformity traps and so on. Unconformity can not only form regional oil- gas migration channel network as excellent lateral oil- gas migration channel, but also the weathered clay layer on unconfunnlty surface can be good cover. However, unconformity may be bad to oil - gas reservoirs in some cases. Structural unconformity can erode the cover forming earlier and transform reservoir, leading to the thickening and missing of oil and gas. In the meantime, the thickening oil can plug the later oil- gas accumulation.