Reservoir Architecture Of Delta On Cretaceous Member Quan 4 In Eastern Dense Wells Block Of Fuyu Oilfields

Exploitation of Fuyu oilfield has entered the stage of high water.The area of oilfield with many blocks is large,so the understanding of the overall macroscopic depositional environment is not uniform.The reservoir heterogeneity of eastern dense wells block is serious,the residual oil distribution and the control factor analysis are not clear,lacking the direction of developing.In this paper,the delta reservoir of eastern dense wells block is taken as the research object,single sand body and its internal architecture in reservoir are studied deeply,and the guidance of reservoir description is further refined.Based on the clustering analysis of the heavy minerals in the whole area,the source and sedimentary characteristics of the Fuyu oilfield are identified.Fuyu oilfield has two sources of southwest and southeast.The western and the middle area are mainly from the source of southwest,and the eastern area is mainly from the source of southeast.Southwestern source gradually advances from the fourth sand group to the first sand group while the southeast source gradually withdrawing,clearing the depositional characteristics of delta plain and delta front of Fuyu reservoir.Through the analysis of the core and the logging curve,the sedimentary microfacies characteristics of K₁q4 in eastern dense wells block are dissected.In the study area,the delta front subfacies are developed.The underwater distributary channel sand bodies are the main sand bodies and the river mouth sand bars are not developed well.This paper summarizes six kinds of spatial contact relationship,three vertical identification marks and five plane boundary identification marks of single sand bodies in the study area.The quantitative evaluation of width-to-thickness ratio of the single sand body in the study area is completed.Quantitative characterization of single sand body internal architecture is summarized.Plane distribution form of underwater distributary channel internal architecture is determined.The effects of single sand body and reservoir architecture on residual oil control are analyzed.