Depositional characteristics of Quantou Formation-Nenjiang Formation in Binbei area,Songliao Basin

Three super sequences can be distinguished from Binbei area.The strata researched belong to the upper part of the super sequence I during the thermal subsidence era.Based on the study on sequence stratigraphy,detailed analysis has been done on the middle-shallow strata in Binbei area,Songliao Basin.According to large number of data from cores and logging,and with the application of sedimentology,it can be found that some types of sedimentary facies developed in the medium to shallow layers include fan delta facies,braided stream facies,meandering stream facies,lacustrine facies,etc.The areal distribution of sedimentary facies is also discussed.According to the source-accumulation assemblage,it can be concluded that the favorable reservoir facies are meandering stream,floodplain,delta,etc.Among them,the under water distributary channel in the frontal edge of the delta possesses the best physical property,and then the delta plain,stream,dam sandbody and fluvial facies belt.Heiyupao-Wuyuer depression,western Mingshui terrace and Anda area are favorable reservoirs.These reservoirs are adjacent to source rocks depression and have the superiority to trap hydrocarbons.