Studies On The Main Controlling Factors Of Typical Stratigraphic Reservoir In Southern Slope Of Dongying Depression

Based on Summarizing the analysis of dates and research results made by the predecessors,this article has combined the petroleum geology,reservoir geochemistry,structural geology as well as inclusion analysis of related theories and methods,studied the main controlling factors of stratigraphic reservoirs of the key blocks in southern slope of dongying depression.The main research area is the jinjia oilfield and the yue an oilfield.There are both oil and gas distribution in the middle and shallow strata of the Dongying depression that is the Guantao group and the Shahejie Formation.The oil and gas in Jinjia oilfield mainly concentrate in the Shahejie Formation;that of Le'an oilfield mainly concentrates in the Guantao Group and Ordovician.In the south slope,shallow seated groundwater is CaCl₂ type and NaHCO₃ type,heavy oil takes the dominant position.As for the physical properties of crude oil,there are significant differences both in the plane and vertical;the density of crude oil in the stratigraphic system in the vertical becomes larger from deep to shallow,and from the depression to the bulge,also becomes lager.Analysing from the plane,the density of crude oil in Jinjia oilfield mainly concentrates in 0.90¹.0g/cm³,That of Le'an oilfield mainly concentrates in 0.95¹.05 g/cm³.On the whole,crude oil density of Le'an oilfield has a larger oil density.Through the research of fluid potential and formation pressure,It has cleared the information of the hydrocarbon accumulation dynamics in middle and shallow layers,also,the dominant migration direction has predicted.Oil and gas moved toward the South and Southeast from Boxing sag,part of the oil and gas accumulated to reservoirs after moved to Jinjia area.The others kept moving toward southeast to Caoqian area and formed Le'an oilfield.Through the fluid inclusion data and sample supplying,based on the research of the predecessors as well as combined the hydrocarbon generation history,the evolution history and the fault sealing history,etc,it studied the hydrocarbon accumulation periods.The oil and gas of Jinjia oilfield and Le'an oilfield are both come from source rocks of the upper Shahejie Formation four and the under section of Shahejie Formation three.The main reservoir forming period is in the period of Dongying formation and late Guantao formation.Based on the south slope of Dongying depression,the distribution characteristics of oil gas migration and accumulation of oil and gas space characteristics and accumulation of power and the times of basic research on conditions of reservoir system,the two areas of typical reservoirs were that the enrichment degree of sealing conditions and migration controls the oil and gas reservoirs are main control the factors on oil and gas.