THINKING ON THE RESEARCH METHOD AND THE CLASSIFICATION OF PETROLEUM SYSTEMS IN THE SUPERIMPOSED BASIN

The train of thought,research content and process of petroleum system analysis in the superimposed basin are raised.Before petroleum systems were classified on the foundation of the contrast of oil source,it is needed to evaluate and study the features of the tectonic framework,the history of sedimentation and filling,the thermal course,the structure unit,the layer of hydrocarbon source rock and the combination of source rock,reservoir and caprock.The hydrocarbon source rock and tectonic unit (hydrocarbon-generating sag and the area that oil and gas migrate and accumulate) are the most major basis of divi-ding petroleum systems because of multiple hydrocarbon source rocks,hydrocarbon-forming units and faults in the superimposed basin.It is suitable and practical to name by combining hydrocarbon source rock,tectonic unit and reliable level.The petroleum system analysis should be made in the two aspects of the static geological essential factors and dynamic geological course.The static geological essential factors include effective hydrocarbon source rock,reservoir,cover layer,transportation layer and trap.Dynamic geological essential factors include forming course of oil and gas,evolution course of reservoir,transporting and moving course of oil and gas,trap-forming course and pool-forming course.All those analysis of the combination relation of essential factors,petroleum system preservation,the conditions of superposition of the petroleum system and exploration targets are component parts of research of petroleum system analysis in the superimposed basin.