BASIN EVOLUTION STAGES AND OIL AND GAS ENRICHMENT——TAKING THE LOWER TERTIARY BASINS IN THE EASTERN CHINA AS AN EXAMPLE

According to petroleum geology evolution of several typical Tertiary basins in the east of China,the process of basin evolution may be divided into three stages of whole descending,whole ascending and whole adjusting.Basin descending stage is the process of material accumlation and energy storage,which causes hydrocarbon formation.Basin ascending stage is the process of energy release and oil and gas reservoir formation.Basin adjusting stage is the process of energy adjusting and material equalization.Based on the analysis of each depression's characters in the basins during the above different evolution stages,we compared the differences of petroleum geology evolution of the oil-rich depressions in the eastern China,and summarized the main control factors of oil and gas enrichment in depressions in the eastern China.It is considered that oil and gas enrich in the basins with full stratigraphic system,moderate sedimentation and denudation.