Identifying hydrocarbon reservoirs in lacustrine rift basins is a challenging task. This study uses seismic, well, and core data to analyse the sequence stratigraphy and describe the depositional systems and hydrocarbon reservoir models in the syn–rifted successions of Sujiatun sag in order to locate prospects in the Late Jurassic–Early Cretaceous continental rift basin. SQ2 is composed mainly of fan–delta and shallow lacustrine depositional systems. SQ3 and SQ4 consist of shallow lacustrine and semi–deep lacustrine depositional systems. SQ5 and SQ6 are composed of braid-delta and shallow lacustrine depositional systems, forming favourable reservoir sand bodies. Data obtained from thin section observation and physical property analysis show that the physical properties of braid-delta reservoirs are better than those of fan-delta reservoirs in terms of hydrocarbon accumulation. Geochemical analysis of the mudstones in SQ3 and SQ4 shows that they are excellent source rocks. Analysis of the conditions and characteristics under which the hydrocarbon reservoirs formed, indicate that Sujiatun sag models can be divided into six categories: a tilted fault–block hydrocarbon reservoir model, Syn trending fault–block hydrocarbon reservoir model, reverse trending fault hydrocarbon reservoir model, fault-lithologic hydrocarbon reservoir model, an updip pinch-out hydrocarbon reservoir model, and a lenticular lithologic hydrocarbon reservoir model. Research indicates that the distinctive depositional systems reflect three episodic syn–rifted stages. In particular, the rift climax influences the development of source rocks. Well-sorted sedimentary conditions and a large number of dissolution pores are key to improving a reservoir. The types and distribution of hydrocarbon reservoirs vary greatly over different structural stages and structural zones. Fault activity and a combination of different faults types, reservoirs, and source rocks jointly determine the enrichment degree of the hydrocarbon accumulation in different reservoirs. This study analyses the sedimentary evolution and hydrocarbon reservoirs within the syn–rifted successi to provide useful insight for oil and gas exploration in syn–rifted basins and may also be effective for use in areas in which wells or outcrop data are lacking.

识别湖相裂谷盆地中的油气藏是一项具有挑战性的任务。本研究利用地震资料、井资料和岩心资料，对苏家屯凹陷同裂陷序列进行层序地层分析，描述沉积体系和油气藏模型，以定位晚侏罗世-早白垩世大陆裂谷盆地的远景。SQ2 主要由扇三角洲和浅湖相沉积系统组成。SQ3 和 SQ4 由浅湖和半深湖沉积体系组成。SQ5和SQ6由辫状三角洲和浅湖相沉积体系组成，形成有利的储集砂体。薄片观测和物性分析数据表明，辫状三角洲储集层的成藏物性优于扇三角洲储集层。SQ3和SQ4泥岩地球化学分析表明，它们是优良的烃源岩。对油气藏形成条件和特征的分析表明，苏家屯凹陷模型可分为六类：倾斜断块油气藏模型、同向断块油气藏模型、逆向断层油气藏模型、断层岩性油气藏模型、上倾尖灭油气藏模型和透镜状岩性油气藏模型。研究表明，独特的沉积系统反映了三个幕式同裂谷阶段。特别是裂谷高潮影响烃源岩的发育。分选良好的沉积条件和大量的溶蚀孔是改善储层的关键。不同构造阶段和构造带的油气藏类型和分布差异很大。断层活动性以及不同断层类型、储层、烃源岩的组合共同决定了不同储层油气聚集的富集程度。这项研究分析了同裂谷系列内的沉积演化和油气藏，为同裂谷盆地的油气勘探提供有用的见解，也可能对缺乏油井或露头数据的地区有效。