Study on the Sedimentary Facies in the Lower Submember of the Uppermember of Silurian Kepingtage Formation,Tazhong Area

Based on drilling cores,mud logging,electric logging,seismic data,etc.,the sedimentary facies and their distribution rules,in the lower submember of the upper member of Silurian Kepingtage formation of Tazhong area in Tarim basin,were studied in the paper.The study shows that the sedimentary environment was barrier coast,which was made up of shoreland,barrier island,tidal flat,and partly braided-river delta.The sedimentary facies in the lower sub member of the upper member were distributed from east to west and different from south to north,in which the facies were gradually changed from tidal flat in the south to the shoreland and continental shelf in the north,and the braided-river delta was independently located along the palaeo-shoreline and laterally to the tidal flat,and they were mostly controlled by the palaeotopography and multi- hydropower.With the overlapping to the south and the multi- sandbodies, there are some possible litho-strata hydrocarbon reservoirs in the lower part of the upper member,which should be next payable target of oil and gas exploration in the area.