The characteristic of triassic sedimentary facies in Che-Guai area of Northwest Margin,Junggar Basin

According to the observation of rock cores,the identification of slices and the analysis of logging,the sedimentary facies of single-well,section and plain,combining the tectonic background and sedimentary environment of this area,we studied the sedimentary characteristics of Triassic in Che-Guai area,northwest margin of Junggar Basin.We found that conglomerate and sandstone mainly develops;the primary provenance is Northwest margin,and the secondary source area is the west area of Well C45.Baikouquan Formation mainly develops alluvial fan and fan-delta deposit,the alluvial fan extends from northwest to southeast.Karamay Formation inherits the sedimentary features of Baikouquan Formation,and mainly develops fan-delta front subfacies extends from northwest to southeast,Baijiantan Formation inherits the sedimentary features of Karamay Formation,and fan-delta front subfacies and shallow lake deposits in chief.From early to late stage,the transgressive sedimentary characteristic of Triassic dominantly controls the distribution of high quality reservoir.