The Research Of Sedimentary And Reservoir Characteristics Of Baikouquan Formation In The West Slope Of The Mahu Depression

Baikouquan Formation is the main reservoir in the west slope of the Mahu Depression,so it is necessary to carry out more research on it.Based on the sedimentary petrology and the reservoir geology theory,combined with core,logging and seismic data,the detailed research were made on sedimentary and reservoir characteristics of Baikouquan Formation in the west slope of the Mahu depression.Through the study of the structure,stratigraphy and sedimentary characteristics of the study area,with the single well facies,well tie facies and seismic data,determined sedimentary facies types and depicted plane distribution range of Huangyangquan fan of Baikouquan formation in the west slope of the Mahu Depression.The Baikouquan Formation in the west slope of the Mahu Depression mainly developed fan delta and shore shallow lake subfacies.Combining the Baikouquan Formation in three layers of the planar distribution of sedimentary facies and evolution history,the depositional model of the target zone in the study area is clarified.Baikouquan Formation in the west slope of the Mahu Depression belongs to the deposition process,with the northwest lake invasion,the sedimentary area of the shallow lake gradually increased,the sediment was returned,and the area of fan delta gradually decreased.Based on the statistical analysis of reservoir physical properties,thin section observation,mercury injection curve,the reservoir petrologic characteristics,physical characteristics and reservoir space characteristics were studied.The research shows that the Baikouquan Formation in the west slope of the Mahu Depression reservoir is low porosity and low permeability reservoir.Together sedimentary features and reservoir characteristics,the main controlling factors of sand conglomerate reservoir are sedimentary microfacies and diagenesis.On the basis of the sedimentary characteristics and glutenite reservoir controlling factors of Baikouquan Formation in the west slope of the Mahu Depression,combined with oil test data,the favorable reservoir zones in the study area can be predicted,they are the fan delta front sandstone and conglomerate which the thickness are large.