Diagenesis of the eighth member of Shihezi Formation in Dingbian area,Ordos Basin

Based on the analysis of casting slice,scanning electron microscope and X-ray diffraction,this paper studied the characteristics of lithology and diagenesis of the eighth member of Shihezi Formation in Dingbian area.The result shows that the main sand bodies in this area are lithic sandstone and lithic quartz sandstone,and the compositional maturity is high and the textural maturity is medium.The sandstone is in the B stage of middle diagenetic stage.The early compaction-pressolution and cementation are destructive for the reservoir properties,while the secondary pores formed by dissolution are constructive for the reservoir properties.The study of diagenesis can provide theoretical criterion for reservoir evaluation and prediction.