Abstract: Through detailed description of sedimentary characteristics of Sangonghe formation reservoir in Shinan oilfield, using geologic, well logging and seismic data, comprehensive analysis on sedimentary environment, sedimentary facies and sedimentary sequences, it is found that Sangonghe formation of Jurassic in this area is mainly a set of braided stream delta deposits. with abundance of, running water structures originated from traction, current genesis. and it is less matured sediments controlled by structural and climate conditions. Comparative analysis between sedimentary microfacies characteristics of braided stream delta front sediments with the oil-gas bearing features has indicated that the underwater distributary channels suitable to hydrocarbon accumulation is a favorable zone for development. The sedimentary microfacies showed important effect on reservoir heterogeneity and oil-water movement.

Key words: Junggar basin, Shinan oilfield, Early Jurassic, reservoir, sedimentary microfacies, oil and gas distribution