NEOGENE PETROLEUM SOURCE AND CHARACTERISTIC OF PALEOGENE HYDROCARBON SOURCE ROCK IN THE RAOYANG SAG, BOHAI BAY BASIN

There are two source rock beds,the lower E_s1 and E_s3 Formation,in Raoyang Sag of the Bohai Bay Basin.The deposition center of the Raoyang Sag was moved from southeast to northwest during the Paleogene.Based on saturated hydrocarbons chromatography and chromatography—mass spectrometry analysis of crude oil and source rocks,the relationship between Neogene crude oil and Paleogene source rocks was studied in the Raoyang Sag.Research has shown that Neogene oil in the Raoyang Sag mainly came from the lower E_s1 source rocks,with the character of the nearest transportation.Affected by the distribution of source rocks,maturity and structure,Neogene oil mainly came from lower E_s1 source rocks in the near oil-generating trough.In Wuqiang—Yangwuzhai area,hydrocarbon source rocks are not in oil-generating stage,Neogene oil mainly came from special lithologic section of the upper E_s3.Besides,there is a phenomenon of mixed-source oil in Maxi area,Neogene oil mainly came from the lower E_s1 in Maxi trough,and some came from the upper E_s3 source rocks.