CONTROL OF THE TERTIARY SYNDEPOSITIONAL STRUCTURES ON SAND AND OIL IN THE DONGYING SAG,THE BOHAI BAY BASIN

The control of the Tertiary syndepositional structures on the deposition,the accumulation of oil and gas in the Dongying Sag,the Bohai Bay Basin has been discussed systematically through the analysis of the relationship between structure,deposition and reservoir forming.The results show that the syndepositional structures provided the basic favorable conditions for the generation,the migration,the accumulation and the preservation of oil and gas.It is pointed out that in order to improve the exploration effect after the large to middle scale oil-gas pools have been discovered,the sequence stratigraphy theory,the petroleum system theory,and the reservoir dynamic forming theory should be fully used in the Dongying Sag in studying the control of the development and evolution process of the syndepositional structures on the process of deposition,trapping and reservoir forming,as well as their relationship with time-space matching.The research on the syndepositional structures is developing from qualitative to time-fixing and quantitative direction,with not only the kinetic mechanism being increasingly attached importance,the simulation of quantitative process also being improved step by step.