Abstract: The Dujiatai pay zone of the Shu266 fault block reservoir consists of fan-delta front deposits,which may be divided into seven microfacies: subaqueous distributary channel,subaqueous interdistributary embayment,mouth-bar,distal-bar,front sheet sand and prodelta mud,of which subaqueous distributary channel sands are the main genetic type of reservoir in the area.In a plan view,the Dujiatai pay zone is highly heterogeneous,while the inter-reservoir and within-reservoir heterogeneities are moderate-high.Microscopically,it is characterized by high coordination numbers and thin throats.The reservoir heterogeneity in the area is mainly controlled by the sedimentary environment.