关键词: 含油气系统, 复合含油气系统, 叠合盆地, 油气勘探, 中国

Abstract: The Chinese mainland is located among the Siberian Plate,the India Plate and the Pacific Plate.Its evolution has undergone the interactive action of paleo-Asian,the Tethysion,and the paleo-Pacific Plates,which resulted in a complicated mosaic tectonic framework of basins and orogenic belts.In this tectonic setting,the sedimentary basins are predominantly of poly-history,which have been superimposed by distinct protobasins forming in different stages.The superimposed basins consist of three basic types,foreland basins in the central and western part of China superimposed on the cratonic basins,the rifting sags and depressions in the eastern part of China superimposed on the cratonic interior depressions and early faulted sags,and the multistaged cratonic interior depressions in the central and western part of China.The petroleum systems occurring in the above-mentioned kinds of basins have shown marked differences from the simple petroleum systems defined by L.B.Magoon and W.G.Dow in 1994.They are predominantly controlled by the basin's tectonic framework.Each type of proto-basin has developed distinct petroleum systems,while the superposition of the proto-basins has resulted in composite petroleum systems.The petroleum systems in the complex-history superimposed basins show a complicated evolutionary history of formation,modification,adjustment,and destruction.The composite petroleum systems in China are thus characterized by multiple source intervals,multiple source kitchens,multiple episode hydrocarbon generation,various periods of pool formation,and multiple critical moments.The petroleum systems usually intersect,interpenetrate or superimpose each other,resulting in two or more petroleum systems combining to make up a much larger and complicated one.Based on the features of its dynamic evolution,the composite petroleum systems in China may be classified into three basic types,namely successive composite systems,modifiedly-successive composite systems,and transformed composite systems.Analyzing the features of composite petroleum systems and developing appraisal and characterization techniques is key to improving the efficiency of petroleum exploration and for developing the composite petroleum systems of China.

Key words: petroleum system, superposition, composition, petroleum exploration