Diagenesis of Reservoir Densification Development in Shanxi Formation of Ordos Basin

The reservoir rocks are mainly quartz sandstones and lithic quartz sandstones in Shanxi Formation of Ordos Basin.The reservoirs are typical low-porosity and low-permeability ones.Based on the core observation,conventional thin section analysis and the thin section fractional analysis,it comprehensively analyzes the sandstone diagenetic types and features of the Shanxi Formation,Yichuan Area in the southeast of the Ordos Basin,combined with the sedimentary burial history and the regional geology characteristics.The result shows that the its diagenesis types are the compaction,the pressure solution,the cementation,metasomasis,alteration,denudation and so on.It'sclear that the diagenesis is the key factor to control the physical property in this area.The compaction and cementation are the main factors that cause the reservoir closeness development.The denudation and metasomasis have an effect on the reservoir pore enlargement at the late stage.