辽河坳陷变质岩古潜山内幕油藏形成主控因素分析

Main factors controlling the formation of interior reservoirs in the metamorphic palaeo-buried hills of the Liaohe Depression

以辽河坳陷西部凹陷兴隆台古潜山为研究对象,总结了变质岩古潜山内幕油藏多层次分布特征,从岩性特征、构造活动、烃源岩、供油"窗口"、封盖体系等方面分析了对古潜山内幕油藏形成的控制作用,建立了变质岩古潜山内幕成藏模式。取得了裂缝发育受构造活动和优势岩性双重因素控制、变质岩古潜山存在多种岩性组合、可形成储隔层交替分布、古潜山侧向供油"窗口"是其内幕成藏的关键、供油"窗口"的幅度决定了纵深方向含油气范围等认识,有效地指导了辽河坳陷古潜山深层的勘探实践。

By focusing on Xinglongtai buried hills in the western sag of Liaohe depression, this article summarizes the distribution characteristics of multileveled interior reservoirs in metamorphic buried hills, analyzes the controlling factors, such as lithologic characteristics, tectonic movements, source rocks, oil charging ＂window＂ and sealing system, upon the formation of interior reservoirs in buried hills, and establishes hydrocarbon accumulation pattern of interior reservoirs in metamorphic buried hills. It concludes that the development of fractures is jointly controlled by tectonic movements and dominant lithology ; the existence of various lithologic combinations in metamorphic buried hills makes it possible for an alternate distribution of reservoirs and barriers; and the lateral charging ＂window＂ for oil migration is the key to the formation of interior reservoirs and its extent determinates the vertical range of oil/gas pools. These understandings effectively guide the exploration in deep buried hills in Liaohe depression.