Research On Sedimentary Microfacies Of Es₂ In Dawangzhuang Oil Field,Chezhen Depression

Dawangzhuang Oil Field is located in the southern Dawangzhuang gentle slope between Dawangbei Sag and Yihezhuang Arch,Chezhen Depression.Es₂ with great exploration potential is the most important hydrocarbon reservoir assemblages in this area.However,due to the lack of research on stratigraphic classification and reservoir characteristic,the sedimentary facies and the accumulation regularity in Da 2,5,13,18 area,exploration has stepped into stagnant period.Based on the precedent outcomes,the modern oil geology theories are utilized to study the sedimentary facies,reservoirs,oil source and characters of oil distribution in this paper with the purpose of clarifying the law of oil distribution and key control factors in Dawangzhuang Oil Field.It is suggested that the Es₂ with angle disconformity contact on underlying Es3 can be divided into four sand groups and 21 small layers from bottom to top.On the whole,due to fault development in Dawangzhuang Oil Field,strata break loss is obvious in Es₂.Es₂ in Dawangzhuang Oil Field is characterized by beach and bar depositional system especially littoral-shallow lake facies.Beach and bar reservoirs are distributed in entire region continuously in the plane,and superimposed each other vertically with good lateral connectivity.The types of sand body of beach and bar are mainly siltstones and fine sandstones with medium porosity and low permeability,accounts for about 90% which can be classified into three types of reservoir namely?,? and ?.The type of ? reservoir and ? reservoir are good reservoirs with fine permeability and mainly distributed in the bar.The hydrocarbon reservoir can be divided into three types namely tectonic reservoir,composite reservoir and lithologic reservoir.Among which reservoirs in the plane are small,scattered and mainly distributed in the beach and bar in the southwest high part.The Es₂ 2+3 sand groups are main hydrocarbon reservoir assemblages,which consist numerous thin oil layers.The Dawangzhuang oil distribution is controlled by three conditions: source,reservoir and tectonic,and the oil field possess the superior conditions of migration,.where faults are developed,with better permeability,making this region to possess good hydrocarbon accumulation..We optimized three favorable exploration targets,namely Da2 fault block reservoirs,Da 5-11 wellblock reservoirs,Da 132 wellblock anticlinal oil and gas reservoirs.,through the seismic profile and characteristics of trap prediction...