Abstract: To address the technical problems of strong heterogeneity and insufficient reserves production in the Linxing Area of the Ordos Basin, the fourth member of the Shihezi Formation in the Linxing Area is taken as the research object, a method combining drilling, logging and seismic data is adopted to carry out fine characterization of three-dimensional spatial sequence stratigraphic framework, and on this basis, the fine description of sublayer sedimentary microfacies of Shihezi Formation and the qualitative and quantitative prediction of tight sandstone “sweet spot” high-quality reservoirs are carried out. The research result shows: The high-quality tight sandstone reservoirs in the Linxing Area are mainly thick tight sandstone river channel sand bodies with porosity of greater than 6%, density of less than 2.55 g/cm³, and v_P/v_S of less than 1.8, and their seismic reflection characteristics are medium-low frequency continuous medium-strong reflection; according to the prediction results of high-quality reservoir “sweet spots”, three-dimensional well locations were deployed to increase the reserves production degree of tight gas reservoirs in Linxing Block by 15.3 percentage points, and the locations of 50 wells were optimized, increasing the gas recoverable reserves by 100×10⁸m³. The research results provide favorable technical support for the three-dimensional exploration and development of unproduced reserves of tight gas reservoirs in the Linxing Area, and have important reference significance for the exploration and effective production of reserves of the same type of tight sandstone gas reservoirs.

Key words: tight gas reservoirs, three-dimensional exploration, reserves production, potential tapping direction, Linxing Area