松辽盆地南部西部斜坡区坡折带作用分析

Analyzing action of slope break zone in western slope area, south of Songliao basin

松辽盆地南部的西部斜坡区在演化过程中形成了多期地层不整合,尤其是断拗转换期的不整合经历了较强褶皱和长时间的抬升侵蚀,为多级次、多类型坡折带的形成提供了背景。通过前期的研究和积累,对西部斜坡区石油地质条件,尤其是隐蔽性油藏成藏条件有了一定的认识。本次研究认为坡折带的分布控制了三级层序的内部格局、沉积亚相及主要沉积微相的分布、超覆圈闭及超覆油藏的形成与分布,同时认为西部斜坡区隐蔽性油藏将成为勘探的新领域,以地层超覆油藏为重点目标的勘探领域将带来新的勘探发现与突破。

The multistage of formation unconformity were formed during the evolutionary process of western slope area, south of Songliao basin, especially the unconformity in fault-to-depression transforming stage experienced stronger fold and long period of lifting erosion, which provided developing background for multistage and multi-type of slope break zones. Through early days' study and accumulation, we have some knowledge of oil-geologic condition in western slope area, especially the reservoir-genesis condition of subtle reservoir. The study considered that the distribution of slope break zone controlled internal pattern, sedimentary sub-facies and major sedimentary microfacies of the level Ⅲ sequence, and formation and distribution of overlap traps and reservoirs; the paper also considered the subtle reservoir in western slope area would become the new area of exploration and the exploration taking the overlap reservoir as a key object would bring new exploration discovery and breakthrough.