The Longmaxi Formation in the Sichuan Basin is a hotspot formation for shale gas exploration. In this paper, taking the Longmaxi Formation shale in Yuxi area as an example, a large number of TOC tests, X-diffraction whole-rock mineral fraction tests, electron microscope observations, physical properties, gas content, and CT scanning experiments were carried out, which in turn analyzed the characteristics of the shale gas reservoir and the factors influencing the gas content. The results of the study show that there are seven types of shale facies developed in Yuxi area, which are organic-rich siliceous shale facies (I), organic-rich carbonate-siliceous shale facies (II), organic-rich clayey shale facies (III), organic-poor clayey shale facies (IV), organic-poor carbonate-siliceous shale facies (V), organic-poor siliceous shale facies (VI), and organic-poor siliceous-carbonate shale facies (VII). The microstructural characteristics of the shale reflect that it was disturbed by multiple environmental factors at the time of deposition, and the sources of brittle minerals include both terrestrial clasts and biogenic siliciclastics. The bottom 30 m shale of Longmaxi Formation has good physical properties and gas content, which is a high-quality target section for shale gas exploration and development. TOC, R_o, permeability, quartz content and clay mineral content all have a significant effect on shale gas content and are important control factors for shale gas content.

四川盆地龙马溪组是页岩气勘探的热点层系。本文以玉溪地区龙马溪组页岩为例，开展了大量的TOC测试、X衍射全岩矿物分数测试、电镜观察、物性、含气量以及CT扫描实验进而分析了页岩气藏特征及含气量影响因素。研究结果表明，玉溪地区发育7种页岩相，分别为富有机质硅质页岩相(I)、富有机质碳酸盐硅质页岩相(II)、富有机质黏土页岩相(II)。 Ⅲ）、贫有机质粘土页岩相（IV）、贫有机碳酸盐-硅质页岩相（V）、贫有机硅质页岩相（VI）、贫有机质硅质-碳酸盐页岩相（VII）。页岩微观结构特征反映其沉积时受到多种环境因素的干扰，脆性矿物来源既有陆相碎屑，也有生物硅质碎屑。龙马溪组底部30 m页岩具有良好的物性和含气性，是页岩气勘探开发的优质目标层段。TOC、R _o、渗透率、石英含量和粘土矿物含量均对页岩含气量有显着影响，是页岩含气量的重要控制因素。