The W formation is the oil measures in Jia oil-gas field.The distribution of oil and gas is controlled by the sedimentary facies. The analysis of log facies plays an important role in the identification of sedimentary facies and the searching for the remaining oil and gas.Depending on the characteristics of log facies,namely campaniform,infundibuliform,box like,dactyloid,linearis,have been identified. Through demarcation of logging facies with core data,and based on the sedimentary microfacies analysis of key well,then the functional relationships between logging facies and sedimentary facies have been established. And then,through the comprehensive analysis of the logging facies of individual wells,the correlation of profiles and the areal study,two kinds of sedimentary facies are recognized,namely delta facies and lacustrine facies.