关键词: 薄层, 砂体预测, 短期旋回, 高分辨率层序地层学, 地震切片, 准噶尔盆地

Abstract: Thin sand bodies are widely developed in the Cretaceous Qingshuihe Formation in the hinterland of Junggar Basin, and the thickness of the reservoir is about 10-20 m. The prediction of thin sand bodies is difficult due to the lack of discernible seismic data. With the data from logging curves and well drilling, and under the guidance of the principle of high-resolution sequence stratigraphy, the first member of the Cretaceous Qingshuihe Formation was divided into 1 long-term cycle, 2 medium-term cycles, and 6 short-term cycles. Within each short-term cycle, 6 seismic inversion slices were preferentially selected through the seismic slicing technique. By this method, the sedimentary evolution characteristics of sand bodies in six different periods, namely, low level period, lake intrusion period, high level period, lake recession period, lake intrusion period, and lake flooding period, within the first member of the Qingshuihe Formation (about 140 m thick) in the hinterland of the Junggar Basin, were identified, thus reducing the multiplicity of interpretations of the seismic data. This paper combines seismic slicing and high-resolution sequence stratigraphy, plays the role of lateral resolution of seismic data and high-resolution of wells, overcomes the lack of seismic resolution, deepens the research on the identification of thin sand body and depositional law in short-term cycle, achieves a good exploration effect, guides the deployment of wells in the field, and serves as a reference for the identification of thin bed in other areas.

Key words: thin bed, sand body prediction, short-term cycle, high-resolution sequence stratigraphy, seismic slicing, Junggar Basin