Abstract Based on the sequence stratigraphy theory, this paper subdivided the Yingcheng Formation into four sedimentary sequences and one volcanic intercalation by means of sequence stratigraphic classification and comparison. According to the analysis of coring data, logging data, palaeontological characteristics, rock slices and grain sizes, the sedimentary facies in Yingcheng Formation should include fan-delta subfacies and lakes subfacies. On plane, the authors used seismic inversion tools to predict the distribution of sand and employed seismic waveform classification technology to do seismic face analysis. With the division results of the microfacies in individual wells, a comprehensive forecast was made for sedimentary facies distribution in Yingcheng Formation, and the evolution regularity on plane was analyzed. During the deposition of the Yingcheng Formation, there was a complete sequence development process in Dongling area. The sedimentary facies assumes an overall EW-striking spreading, with obvious variations in the NE direction. Material source from the northeast was adequate, and the sedimentary facies on the whole formed an integral sequence sedimentary sequence, reflecting the sedimentary characteristics of the lacustrine plane from expansion to shrinkage.
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