Characteristics of sedimentary microfacies of Upper Triassic Chang 6 reservoir in Weibei area of Ordos Basin

Chang 6 reservoir of Yanchang Formation in Weibei area is mainly composed of gray fine sandstone and siltstone. Based on core observation, single well facies and logging data analysis, the characteristics of sedimentary microfacies and the distribution of microfacies in each sublayer of Upper Jurassic are systematically studied. The results show that braided river delta front and turbidite are the main deposits in Chang 6 reservoir in Weibei area. The subaqueous distributary channel, mouth bar, distal bar, sand sheet and interdistributary bay are the main sedimentary microfacies of the braided river delta front. The study results settle a strong base for the prediction of favorable reservoir facies belts and the further exploration.