Abstract: Through the research on microscopic sedimentary facies in Sha member 4 in Weicheng oil field, Dongpu depression, such microscopic sedimentary facies are identified from fan delta sedimentation as channels, interchannels, sheetshaped sands and deepsemi deep lacustrine. The established chief microscopic facies well logging model is employed to identify and classify single well facies, well logging plane facies association is studied, the plane figure of microscopic sedimentary facies in Sha member 4 is plotted based on the figure of sand body distribution. The prediction to sand body distribution and microscopic sedimentatary facies indicates that there is material source at southern edge of the studied area, there probably is the favorable microscopic facies such as branched channels and interchannels at the south of Weicheng oil field, there exists favorable sandbodies. Combined with reservoir prediction result, the ongoing exploration targets are sorted out optimally, the good results are achieved in 4 planned drilled wells, which proves that there is a bright oilbearing prospective in the area.

Key words: microscopic sedimentary facies, reservoir prediction, ongoing exploration, exploration target, Weicheng oil and gasfield