Using a series of analyses including core observation,conventional polarization microscope,X-ray diffraction,SEM,and well log,this research studied the mineral composition,organic geochemical features,storage space,physical property and gas-bearing,and categorized the black shale in the study area.The key factors that affect shale gas reservoirs were analyzed,and the favorable area was recognized.The results show that fourteen lithofacies are identified based on our classification.The black shale has a high total organic matter content and high maturity.With a high free gas content,the siliceous shale has the best physical properties and gas-bearing;the next is the mixed shale,and thc calcareous shale has the least favorable physical properties and gas-bearing,in which almost no free gas is contained.Free gas is the main factor that affects the total gas content.SEM observations show that interparticle pore mainly develops along quartz in the siliceous shale;and the development of interparticle pore is the key factor that lead siliceous shale to be the best shale reservoirs with better physical property,gas-bearing and high free gas content.In the study area,TOC and lithofacies are the major factors affecting the shale gas reservoir.The transitioning area mainly develops siliceous shale,the total thickness of type Ⅰ and type Ⅱ reservoirs can reach 44.7 m,which is the most favorable exploration region.%通过岩心、薄片、X-衍射、扫描电镜、测井等分析测试,对川南地区威远、长宁、昭通三区块五峰组-龙马溪组黑色页岩矿物组分、有机地化、储集空间、物性和含气性特征进行研究,制定页岩岩相划分方案,分析黑色页岩储层控制因素,优选研究区有利储层.结果表明:根据有机组分和无机组分相结合原则制定的岩相划分方案在研究区识别出14种岩相;目的层黑色页岩有机质含量高,均值大于2％,有机质成熟度高,等效镜质体反射率均值为2.5％,处于高成熟阶段;硅质页岩物性和含气性较好,游离气组分含量较高,混合型页岩次之,钙质页岩物性和含气性最差,几乎不含游离气,游离气是导致硅质页岩含气性较好的重要因素;粒间孔隙主要沿石英颗粒发育,多为宏孔,主要发育于硅质页岩中,是造成硅质页岩物性及含气性好、游离气组分含量较高的主要原因;长宁地区主要发育Ⅰ类储层,Ⅰ类和Ⅱ类储层累计厚度可达44.7m,是研究区页岩气储层最有利区块.
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