辽河西部凹陷南段隐蔽油气藏的形成条件与分布规律

辽河西部凹陷南段烃源岩、储集岩和盖层条件十分优越,形成多套有利的储盖组合。该区烃源岩生烃期、排烃期与圈闭形成期配置合理,具备形成多层位岩性地层油气藏的条件。主要发育地层、岩性和复合等隐蔽油气藏类型。油气分布规律为:纵向上,主要储盖组合类型控制了隐蔽油气藏的分布层位;平面上,受凹陷地质结构控制,不同构造位置发育不同类型的隐蔽油气藏。认为同沉积断裂带之下的有利储层发育带,即陡坡和缓坡坡洼过渡带是该区有利的岩性油气藏发育区带。

Accumulation Conditions and Distribution Regularity of Subtle Oil-gas Reservoirs in Southern Segment of Western Sag of Liaohe Oilfield

The conditions of source rocks, reservoir rocks, and cap rocks are favorable in the southern segment of western sag of Liaohe Oilfield, where several favorable reservoir-cap rock associations come into being. The configuration of hydrocarbon generation and expulsion stage of source rocks and trap formation stage is reasonable in this region, which is favorable for forming lithologic stratigraphic oil and gas reservoirs with multi strata. Subtle oil- gas reservoir types, such as stratigraphic, lithologic, and complex reservoirs, mainly developed in the region. Vertically, the distribution of subtle reservoirs is controlled by some main reservoir-cap rock combinations. Horizontally, controlled by the geological structure of sags, subtle reservoirs of various types developed in different formations. It is believed that favorable zones for the development of reservoir under the same sedimentary fractured zones, that is, transitional zones of slopes and depressions with abrupt or gentle slope, are favorable for developing lithologic oil and gas reservoirs.