陆相断陷湖盆深盆油气藏研究——以泌阳凹陷中南部为例

深盆油气藏是一种形成条件特殊，具有特殊圈闭机理、分布规律及流体关系倒置的非常规油气藏。与前陆盆地和克拉通盆地相比，陆相断陷湖盆深盆油气藏的形成条件较差，实例也较少,泌阳凹陷中南部的实钻、测试资料证实该区不仅发育气水倒置，而且还存在油水及油气关系倒置的层状深盆油气藏。文章通过总结深盆油气藏的成因机制，分析研究区的成藏条件，类比不同盆地中该类油气藏的特征，认为陆相断陷湖盆中可以形成有商业价值的深盆油气藏，但规模有限；巨厚的优质烃源岩，连片分布的致密储层，交互叠置的生储配置及裂缝、微裂缝的发育是其成藏关键因素。

A STUDY OF DEEP-BASIN OIL AND GAS ACCUMULATION IN NONMARINE RIFTED LAKE BASIN:TAKING SOUTHERN-CENTRAL PART OF BIYANG SAG AS AN EXAMPLE

Deep-basin oil and gas accumulation is a kind of unconventional hydrocarbon reservoirs formed under unique conditions, with special trapping mechanism, distribution pattern and inverted fluid contact relationship. Compared with foreland basin and cratonic basin, the forming conditions of deep-basin accumulations are poorer in nonmarine rifted lake basins and case studies are less. Drilling and testing verify that both layered deep-basin accumulations with inverted gas-water contact and that with inverted oil-water or oil-gas contacts are developed in the middle-south of Biyang sag. Based on study of the genesis of deep-basin accumulations, an analysis of reservoiring conditions in the study area and a comparison of this kind of reservoirs in different basins, it is believed that commercial deep-basin oil and gas accumulations can be formed in nonmarine rifted lake basins, but their scales are limited. It plays a key role in reservoiring that includes tremendously thick source rocks of high quality, extensively distributed tight reservoirs, superimposed source rock and reservoir rock combinations, development of fractures and microfractures.