十屋断陷含油气系统及勘探潜力分析

Petroleum system in Shiwu Faulted Sag and analysis of exploration prospect.

十屋断陷位于松辽盆地东南隆起区,下部是西断东超的箕状断陷,上覆沉积为坳陷地层沉积。断陷地层的暗色泥岩是好的油气源岩,最好的储集层是坳陷层的泉头组。构造运动控制了盆地的演化、油气的生成、构造圈闭的形成、原生油气藏的破坏及浅部次生油气藏的形成;沉积环境控制了源岩和储层的发育特征、油气分布层位及原生油气藏的形成。嫩末构造运动控制局部构造的油气分布层位及次生油气藏的形成。处于休眠期的断裂作为遮挡,形成断鼻、断块圈闭,能够聚集油气形成油气藏;活动时期的断裂能作为垂向运移通道,并在浅部形成断鼻和断块次生油气藏。

Shiwu Faulted Sag locates at the southeast uplift of Songliao Basin. The sag overlies a dustpan-shaped faulted sag that faults to the west and overlaps to the east, and underlies a sagging stratum. The dark mudstones in the faulted sag are good source rocks, among which Quantou Formation is the best reservoir in the sagging stratum. Tectonic movement controls the evolvement of the basin, generation of petroleum, formation of traps, destroy of primary oil gas pool and the formation of secondary oil gas pool in the shallow. Depositional environment controls the growing characters of source rocks and reservoirs , hydrocarbon occurrence layers, and the formation of primary hydrocarbon. The tectonic movement at the end of Nenjiang Movement time controls hydrocarbon occurrence layers in local structures and the formation of secondary hydrocarbon pool. Fractures in dormancy constitute traps of faulted noses and fault block, which are favorable for accumulation of hydrocarbon. Actives fractures act as vertical migration pathway, facilitating the formation of hydrocarbon concentration in shallow parts.