Sedimentary Characteristics And Sand Body Distribution Of Chang6 In Middle Zhaizihe Oilfield

In order to clarify the sedimentary characteristics and sandstone distribution of Chang 6in Zhaizihe Oil Region of Wuqi oilfield,based on the data of core analysis,well logging and laboratory analysis,and guided by the theories of stratigraphy,well logging geology,sedimentology and reservoir geology,this paper studies the sedimentary microfacies and sand body distribution of Chang6 in zhaizihe oil area.On the basis of previous studies,the corresponding stratigraphic framework is constructed by using the methods of marker bed,stratigraphic thickness and adjacent well correlation.Histogram and trend surface method are selected to standardize all logging curves in the study area.Based on the characteristics of logging response,the relationship between rock and electricity of Chang 6 in the study area is analyzed,and a lithologic interpretation model constrained by geological conditions is established,which is used to interpret and verify the rock properties of more than 200 wells in the study area.According to the difference of core facies and logging facies,the sedimentary facies of Chang 6 in the study area is divided into a delta front subfacies,and further divided into three sedimentary microfacies:underwater distributary channel,mouth bar and distributary bay,and the characteristics of each microfacies are summarized.On this basis,combined with the results of lithologic interpretation,the horizontal distribution,vertical evolution and plane distribution of sand bodies in different sedimentary periods are further analyzed.The results show that the distribution of sand bodies in Chang 6 reservoir has a strong regularity.The development of sand bodies from Chang 6₃,Chang 6₂ to Chang 6₁ is getting better,and Chang 6₁ sandstone is the best.On the basis of the above work,combined with the analysis results of sand body and logging facies,the distribution characteristics of sedimentary facies are obtained,which provides an important basis for further oil exploration and deployment.