Application of particle size analysis to study of sedimentary facies of the second member of the upper triassic xujiahe formation in the south area of the west sichuan province

Research of sedimentary facies is important for modern oil and gas exploration and development.Model building of different facies and micro-facies analysis will guide establishment of the control factors of oil and gas.Particle size characteristics of the 2nd Member of Upper Triassic Xujiahe Formation are systematically researched and morphology of different curves and particle size parameters analyzed.Sedimentary facies in the study area are discriminated with Sahu discriminant function and CM diagram.The analysis results show that the sedimentary facies in the Upper Triassic Xujiahe Formation is mainly characterized by braided river delta,dominated by the traction current.