The study focused on understanding the characteristics of the Chang 8 Oil-bearing Formation in the Ordos Basin. Researchers analyzed rock composition, pore structures, and sedimentary facies in the Wuqi-Dingbian area. They found that the reservoir mainly consists of sandstone with clay and carbonate cements. Pores are mainly intergranular dissolved pores. The reservoir has low initial expulsion pressure and high median expulsion pressure. The formation in the area developed from shallow water terrace type deltas sourced from different directions, with deltas from the northwest and northeast dominating. Subaqueous distributary channels of the deltas widen and become sheet-like near the river mouth.