Research On Geochemical Characteristics And Petroleum Migration Of Paleogene In Fang Zheng Fault Depression

Based on the theories of petroleum geology, structural geology and sedimentology, the thesis researches thoroughly geochemical characteristics of hydrocarbon source rock, crude oil and petroleum migration, combining with various of data about geology, geochemistry, geophysical prospecting, logging, well logging and core. Through the data of geochemistry focuses on Fangzheng fault depression hydrocarbon source rocks characteristics to determine the distribution of the source rocks. On the basis of characteristics of geochemical characteristics of crude oil carries through oil-source correlation and inferred the source of crude oil. Furthermore, the thesis concludes hydrocarbon migration direction and channels simply. In the end, the thesis analyzes the main controlling factors of hydrocarbon accumulation and predicted the favorable exploration region.In the vertical,source rocks develops Xin'an cun and Wuyun Groups, Da Lianhe Group and Bao Quanling Group of Palegogene in Fangzheng fault depression mainly. By analyzing dark mudstone to determine source rock of Fang Zheng fault depression are mainly distributed in Xin'an cun and Wuyun groups. The hydrocarbon source rocks reaches high organic abundance and maturity ,while the kerogen types II2-â…¢mainly. In the plane, hydrocarbon source rocks locate Oaktree hillrock sub-sag, Da lianhe sub-sag and De Shantun sub-sag of north depression. As comparing with saturated hydrocarbon gas chromatography and biomarker's characteristics of oil from Fang 4, Fang 6, Fang10 analyses oil from the same source of Xin'an cun and Wuyun Groups. Besides, crude oil has the characteristics of coal-formed oil. On the migration combining with oil geochemical indexes and geological structure concludes that faults maybe the main channel migration.Through the comprehensive research of reservoir forming conditions speculates the most favorable prospecting areas are middle-south of Oak tree hillrock sub-sag and the north of Da Linzi sub-sag. In addition, the east of Central Salient, De Shantun sub-sag, the north Oak tree hillrock sub-sag, the west of Central Salient and the south of Da Linzi sub-sag are more favorable prospecting areas.