Dynamic System Of Oil And Gas Migration And Accumulation Of The North Part Of Dongpu Depression

Under the guidance of theories of dynamic system for hydrocarbon migration and accumulaton and sequence stratigraphy,and based on research of structure and sedimentary geology ,drilling,seismic,logging,testing and organic geochemical data are fully utilized to analyze systematically,dynamically and macro-micro compansively the dynamic system for hydrocarbon migration and accumulaton in this depression。The mud abnormal fluid pressure is mainly appears in ES31, ES32and , ES33,two over pressure zone can be identified.by formation test,the sand reservoir bed fluid pressure canbe divided into four belts,ie.,top normal pressure belt,upper high pressure belt,middle supper high belt and lower high pressure belt. Latterly, the lower belt appears one cengter; the middle and upper belt appears as east pressure zone and west pressure zone respectively. Paleo-geothermal gradient was assessed by fluid inclusions testing and apatite fission track analysis. The eroded sediment thickness of Dongying formation in Dongpu depression is estimated by mud compaction curve.Based on the analysis of the strata fluids pressure,salt-gypsum bed distribution and sequence stratigraphy oil and gas-source rock relationship and the north part of Dongpu depression are divided into 4 dynamic system vertically.The essential elements of the conduction system include sanddodies and faults, which combine together to form carrier system.Based on fetch area divided accoding to arry lines of fluids potential at main hydrocarbon expulsion stage,combine with the research of sealing faults,the north part of Dongpu depression are divided into 8 fetch units.The hydrocarbon generating history both C-P and Paleogene source rock was analyzed. From oil and gas distribution, pressure system characteristics, and source rock of twe model dynamic system are summerised. Through gas source tracking and correlation, link system,migration fluids phase and dynamic,pool forming process and preserve, the oil and gas reservoir forming mechanic was detailed analyzed finaly, the oil and gas ccumulation law was summarized and the available target was pointed out.