Features and Influencing Factors of Yangchang Formation Reservoir in Fuxian-Huangling Exploration Area, Erdos Basin

In this paper, the reservoir characteristics of the Yanchang Formation in the Fuxian-Huangling area have been studied in detail using the data of rock thin sections, cast thin sections, mercury intrusion and physical properties, and the affecting factors of the reservoir properties in this area have been analyzed in multiple perspectives. The results show that the sedimentary rock types in the study area are mainly feldspar sandstones, the interstitial materials are heterogeneous and cement, the hetero-base is mainly hydromica with less content;The cement has high content, in which the calcite has highest content, and the anhydrite has least content. The pore type is mainly composed of intergranular pores and dissolution pores;The throat is fine, which is characterized by fine tunnels and microchannels;The reservoir properties are poor, and they are low porosity, low permeability-ultra-low permeability reservoirs, with main reservoir space of pores;The best physical properties in this study area are sedimentary microfacies, the second ones are estuary dam and mat sand, and the worst one is turbidite fan. Finally, it is concluded that the compaction and cementation are the most important reason for forming the ultra-low porosity reservoirs of the Yanchang Formation reservoirs in the Fuxian-Huangling area.