Abstract: In recent years, several wells in Santai area in the east of Junggar Basin have obtained high-yield industrial oil-gas flow in the Permian System, showing the characteristics of multiple-layer complex oil-gas accumulation, and great exploration potential in oil-gas rich zones. Based on drilling, logging, sample analysis, and oil testing data, a systematic study is performed on the enrichment conditions and reservoir formation characteristics of multi-layer oil-gas, so as to deeply investigate the geological characteristics and exploration prospects of multi-layer oil-gas in Santai area and its surrounding areas. Santai area is adjacent to the hydrocarbon rich sag and is supplied with multiple sources of hydrocarbons from the Carboniferous, Permian, and Jurassic reservoirs. The Permian Lucaogou Formation is the primary source rock of oil-gas in the study area. Under the tectonic setting of low uplift, the trough system is developed, and large-scale sand bodies are developed in the main trough area, characterized by "trough controlling sand bodies". Multiple sets of positive cycle sedimentary combinations are developed in Carboniferous and Cretaceous reservoirs, and possess favorable reservoir-cap conditions. There are differences in the main control factors for oil-gas accumulation in different layers. The Carboniferous is controlled by fault fractures and structures, characterized by mixed-source hydrocarbon supply, where fault blocks or stratigraphic oil-gas reservoirs are mainly developed. The Permian is controlled by faults, paleogeomorphology and lithologic pinch-out, characterized by single-source hydrocarbon supply, where fault-lithologic petroleum reservoirs are developed. The Permian and Jurassic are controlled by faults and lithologic pinch-out, where faults and fault-lithologic petroleum reservoirs are developed. Tectonic activities are strong in the southern part of Santai area and the Ji'nan uplift, due to which large faults are developed, and there are favorable conditions for oil-gas migration and accumulation; they are key areas for multi-layer exploration, and the predicted resource is about 2.45×10⁸t.

Key words: accumulation condition, Santai area, oil-source correlation, reservoir-cap assemblage, hydrocarbon accumulation mode, favorable exploration zone

摘要： 近年来，准噶尔盆地东部三台地区多井获得高产工业油气流，展现出多层系复式油气聚集的特征，显示出富油气区带的勘探潜力。为深入研究三台地区及其周缘多层系的油气地质特征及勘探前景，结合钻井、录井、分析化验及试油资料，对研究区多层系油气富集条件及成藏特征开展了系统分析。三台地区紧邻富烃凹陷，受石炭系、二叠系、侏罗系多源供烃，其中，二叠系芦草沟组是主要的烃源岩层，其他层系在低凸起构造背景下，沟槽体系发育，主槽区发育规模砂体，具有"沟槽控砂"的特征。石炭系—白垩系发育多套正旋回沉积组合，储-盖条件优越。不同层系的油气成藏主控因素存在差异：石炭系受断裂和构造控制，多源供烃，多发育断块或地层型油气藏；二叠系受断裂、古地貌及岩性尖灭控制，单源供烃，发育断层岩性型油气藏；三叠系—侏罗系受断裂和岩性尖灭控制，发育断块或断层岩性型油气藏。三台地区南部及吉南凸起的构造活动强烈，南部阜康断裂带断块群大型断裂发育，油气成藏条件优越，是多层系立体勘探的重点领域，预测资源量约为2.45×10⁸t。

关键词: 成藏条件, 三台地区, 油源对比, 储-盖组合, 成藏模式, 勘探有利区