Evaluation of Shale Gas Resource Potential in the Lower Cambrian Niutitang Formation at the Southwest Edge of Xuefeng Uplift

According to the drilling and profile data of the Lower Cambrian Niutitang Formation in the southwest margin of Xuefeng uplift, the geological characteristics of shale gas in the Niutitang Formation are summarized and the favorable areas are optimized. The research results show that:（1）The organic-rich shale deposits of Niutitang Formation in the study area are controlled by the deep-water shelf environment, and the thickness gradually increases from northwest to southeast.（2）The organic matter abundance of organic rich shale in the Niutitang Formation is high, with an average TOC of 4.95%; Cheese root δ The average value of 13C ranges from -33.04 ‰ to -33.87 ‰, indicating type I kerogen; The maturity of organic matter Ro is mostly between 2.4% and 2.6%, and the degree of thermal evolution is moderate.（3）The Niutitang Formation has a high content of quartz minerals, and the storage space is mainly composed of intergranular pores, intragranular pores, organic matter pores, and fractures. The average porosity is 6.78%, and the average permeability is 0.0580×10^-3μm² belongs to low porosity and low permeability - low porosity and ultra-low permeability reservoirs;（4）Using multiple factor superposition method, three favorable areas for shale gas exploration in the Niutitang Formation of Danzhai, Xuanwei, and Majiang were selected, with a geological resource of 3995.39×10⁸m³.