Sedimentary facies and model of Chang 6 member of Yanchang Formation in Dalugou District 2

This paper studies the rock types,sandstone structure,sedimentary tectonics,paleontologic evidence and electrofacies of Chang 6 member of Yanchang Formation of Upper Triassic in Daliugou District 2 of Jing'an Oilfield,Ordos Basin.The types and characteristics of sedimentary facies are analyzed in detail.The results shows that during the Chang 6 reservoir sedimentary period, the meandering river delta sedimentary system develops,the meandering river delta facies develops a subfacies of delta front and the delta front develops six microfacies as underwater distributary channel,underwater distributary channel flanking,channel mouth bar,sheet sand,distributary interchannel and interdistributary bay.Based on the sedimentary system and plane distribution features, two sedimentary models were built,which are branch-shape and cloud-shape sand body sedimentary models.