Analyses of Controlling Factors on Hydrocarbon Accumulation of the Upper Paleozoic in Chengdao Area, Jiyang Depression

In order to clarify the exploration direction of the upper Paleozoic in Chengdao area, this article applied the comprehensive analysis technology of oil and gas accumulation and seismic and borehole data to study its structural characteristics, stratigraphic residual and reservoir development, finally discussing the conditions of oil and gas accumulation and main controlling factors of hydrocarbon accumulation. The results show that the upper Paleozoic is the "spindle type" distribution, structural and structuralstratigraphic traps were formed because of fault and stratigraphic, affected by the multi-period tectonic movements. Hydrocarbon from Shanan sag travelled along the faults and unconformities to buried hill traps. Oil source and migration condition are the prime requirement of reservoir formation and the cap rock condition controls the specific horizons of reservoir formation. Meanwhile, the trap and preservation conditions are the critical factors to reservoir formation, especially the lateral sealing of faults. It is pointed out that the consequent fault block traps, composite traps of structure-strata and traps formed by internal faults are favorable exploration directions for the next step.