Microstructural Characteristics and Gas‐bearing of the Upper Cretaceous Qingshankou Formation Shale, Southern Songliao Basin

Southern Songliao basin consists of four A structural units from west to east:western slopes,southwest ridge,central depression and southeast uplift.Upper Cretaceous Qingshankou Formation shale sedimented in large-scale invasion of the lake,with a quick settlement,super fast filling compensation deposition characteristics and widely deposition of organic-rich,thick black shale interbedded oil shale,which is the most important source rocks on Songliao basin.The main organic matter types of