Abstract: The composite petroliferous basin in China has long period of geological evolution history,multiple depositional sequences and intensive tectonic deformation. The petroleum system developed in this type of basin has some complex characteristics. One petroleum system commonly comprises several source layers or source kitchens,and experienced multiple periods of hydrocarbon generation,migration,accumulation and adjustment;hence the forming of hydrocarbon reservoirs might have several critical moments. Moreover, hydrocarbon fluid exchange often occur among systems through common migration paths,such as fault,unconformity,fissures created by over-pressured fluid,and lapped sand body,so that several source kitchens may charge a single reservoir. In accordance with the above complexity of the petroleum system in China,this paper introduced the concept of multi-source petroleum system, as well as its major characteristics, description methods and exploration techniques. A proposed research procedure starts with the description of the source kitchen,then following the nature process of hydrocarbon generation,migration and accumulation,focuses on the study of characteristics of geological elements and their combination at the critical moment, and the space of hydrocarbon migration and accumulation. The analyses of fluid migration history,basin simulation and the other modern exploration techniques played an important role in the description and evaluation of a multi-source petroleum system.

Key words: multi-source petroleum system, composite basin, fluid exchange, exploration technique, China

摘要： 中国叠合含油气盆地具有演化历史长、沉积层系多、构造变动强烈等特点。其中发育的含油气系统常表现出多源多灶多期生烃与运聚成藏以及成藏后多期调整改造的复杂性,形成过程有多个关键时刻,而且由于断层、不整合、砂体和裂缝等通道的连接作用,系统之间可发生烃类流体交换,形成多源油气的混合聚集。鉴于中国含油气系统的复杂性,提出复合含油气系统的概念,并总结其基本特征、描述方法和勘探技术。建议从生烃灶确定开始,以顺藤摸瓜的方式,确定不同关键时刻,理清各成藏地质要素特征与空间组合关系,指出油气运移和聚集的空间范围。流体历史分析与盆地模拟等现代勘探技术的配套使用在复合含油气系统描述与评价中发挥着重要作用。

关键词: 复合含油气系统, 叠合盆地, 流体交换, 勘探技术, 中国