Research on Sedimentary Microfacies of Fourth Section of Quantou Formation in Liangjing Gudian Area of Songliao Basin

Based on areal geologic background, integral analysis on core observation, particle size analysis, and logging curve shape indicates that the fourth section of Quantou formation in Liangjing Gudian area is of delta-front and shore shallow lacustrine depositional systems. Two major river systems which come from southeast and southwest supply the source materials to this area. Especially, the microfacies of delta plain mainly developes subwater distributary channels,its flank, subwater interdistributary bay, and the delta front mainly consist of interchannels, debouch bars, far bars and mat shape sands. In this area, the distributary channel constitutes the dominated reservoirs. The research result firstly explains the sedimentary microfacies' space-time distributing characters, and provides geologic base for the further exploration and development.