The chemical compositions of 20 crude oils and the extracts of potential source rocks from the Jinhu Depression of the North Jiangsu-South Yellow Sea Basin, eastern China were studied in detail by geochemical methods in order to understand their genetic relationship. The oil samples were collected from the major producing fields in the Western Slope (WS) and the Biandong-Yangjiaba-Minqiao uplift belt (BMY). The rock samples studied, selected after Rock-Eval pyrolysis screening of a large suite of samples, consist of 20 shale samples in the E2f2 member of the Paleocene Funing Formation from the oilfield areas (WS and BMY) and the Sanhe sag all within the Jinhu Depression. Geochemical characteristics indicate only one single family of oils. A number of biomarker features support deposition of the source rocks for these oils under conditions of enhanced salinity/stratified water columns. A wide thermal maturity range for the oils as indicated by sterane isomerization ratios was not substantiated by other maturity parameters. The genetic relationships between the oils and the E2f2 member of the Paleocene Funing Formation present in the deeper parts of the Sanhe and Longgang sags were suggested using a wide range of molecular parameters. Variation in the sterane concentrations in source rocks with different maturity suggests that migrational contamination and/or in-situ extractions of organic matter from caprocks or intra-reservoir shales by mature oils could potentially produce oils with apparent immaturity at the molecular level. Secondary alteration (e.g. biodegradation) of oils in the reservoir could also have a similar effect on the bulk oil compositions. Although we do not discount the possible presence of minor amounts of "immature oils", exploration focus in the Jinhu Depression, as well as many other rift basins in eastern China, should be on mature oils derived from the deep source kitchens.

根据油气运聚的动力和作用方式将油气藏成因分为3类8种17式。这8种分别是：①高压势场作用下形成的油气藏；②低压势场作用下形成的油气藏；③由水携带溶解气游离释放形成的天然气藏；④浮力作用下形成的油气藏；⑤毛细管力作用下形成的油气藏；⑥天然气体积膨胀形成的深盆气藏；⑦分子吸附作用形成的煤层瓦斯气藏；⑧分子水合作用形成的水合甲烷气藏。①～③种为突发式流压作用形成的油气藏，④～⑥种为缓慢式烃势差形成的油气藏，⑦和⑧为非常规条件下天然气汇聚形成的特殊类型的（油）气藏。相同动力学成因的油气藏因实际地质条件的差异可以进一步分成亚类。不同动力学成因的油气藏的分布规律、主控因素和产状特征不同。研究油气运聚的动力机制和成因模式对指导油气田勘探提高勘探效益具有重要意义。

The mature oil/gas source rocks exist mainly in Jurassic strata in the northwest and in Tertiary strata in the west of Qaidam Basin. Oil and gas generated from the mature hydrocarbon source rocks in the Jurassic and Tertiary mainly accumulate in Tertiary formations in the Qaidam Basin. The main sedimentary facies in Tertiary formations include alluvial plain, lakeshore, shallow lake, semi-deep lake, alluvial fans, fan delta and sublacustrine fan. However, there were no fluvial facies. Most of the alluvial plain facies and lakeshore facies are very narrow and they become wide only where basin-bounding faults are present. Most parts of the basin are filled with shallow lake sediments such as pelitic siltstone and silty sandstone. The deposition systems have determined the hydrocarbon migration and accumulation patterns in Tertiary formations in different parts of the basin. In the inner basin where continuous permeable formations are absent, faults and fractures are the main pathways. Fractured rocks are the main reservoir types. Along the basin margins where continuous permeable formations occur in abundance, faults and fractures are also the main pathways. Therefore, the faults and fractures are very important for the hydrocarbon migration and accumulation. Four migration and accumulation models have been developed based on this study: (1) Migration and accumulation model through thrust faults. This model is mainly for migration and accumulation at the basin margin. The mudrock associated with the major fault is about 10 m thick so that there exist the hanging wall and footwall migration and accumulation zones. Where the major fault extends into source rocks areas, hydrocarbon migrated to and accumulated in the reservoir in the hanging wall. Otherwise, the faults just seal the reservoir in the footwall. (2) Migration and accumulation model through combined syn-depositional reverse faults and strike-slip faults. This model is also mainly for migration and accumulation at basin margins in which the strike-slip faults control different kinds of sedimentary fans and connections with hydrocarbon source areas; they are very suitable for hydrocarbon accumulation. (3) Migration and accumulation model through recoil faults. This model is mainly for migration and accumulation in fractured reservoirs in the inner basin region. (4) Migration and accumulation model through superficial thrust fault and lower strike-slip fault complex. This is mainly for migration and accumulation in the north of Qaidam Basin where the reservoirs are at the footwall of the superficial thrust faults.

油气在生排运聚成藏过程中须经历生烃排烃、运烃、聚烃和资源等5个门限。某一确定的油气运聚成藏系统进入任一个门限都将损耗一部分烃量。在实际地质条件下，源岩生成的烃量只有超过进入各个门限时损耗烃量之和才能大规模聚集成藏，并构成油气勘探的远景区。根据物质平衡原理研究油气生成量和损耗量之间的平衡关系，建立了相应的地质模型。在此基础上，提出了门限控烃作用及其计算模型。文中阐明了各门限的地质含义、判别标准及其控油气作用机理，给出了应用实例。