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须家河组天然气成藏受层序地层格架的控制。Ⅲ１层序先后沉积了包括碎屑岩构成的低位体系域，泥岩、砂质泥岩构成的水进体系域和砂岩、砂质泥岩、煤层构成的高位体系域，显示了由川中向川西前积充填的特征；Ⅲ２层序则先沉积了由湖泊及进积三角洲沉积构成的低位体系域，后又沉积了主要由泥质岩构成的水进体系域，形成由周缘向盆地内部充填的沉积格局；Ⅲ３层序在沉积了由巨厚盆底扇构成的低位体系域后，继之形成了由湖泊、退积三角洲沉积体系构成的水进体系域，后又充填陆源碎屑为主的高位体系域，亦具由周缘向盆地内部前积充填的沉积特色。水进体系域因其泥岩厚度大，有机碳丰富为主要烃源岩及区域盖层，低位体系域和高位体系域由于砂岩孔渗性好是为储集层。川中、川西北以Ⅲ１层序低位体系域为主，次为Ⅲ２层序低位体系域，川东、川南以Ⅲ３层序高位体系域占优势。显示天然气成藏分布由须家河组二段低位体系域占优势转变为须家河组五段上部高位体系域为主，有利储集相带向东迁移的趋势。
Natural gas accumulation in Xujiahe Formation is controlled by the sequence stratigraphic framework. The sequence of Ⅲ1 sediments have successively deposited water systems consisting of lowstand systems tract composed of clastic rocks, mudstone and sandy mudstone into system tract and sandstones, sandy mudstone and highstand system tract composed of coal seam, In the sequence Ⅲ2, the lower system tract consisting of lacustrine and sedimentary delta sediments is deposited first, and then the sedimentary system consisting mainly of muddy rocks is deposited into the system tract. . After the deposition of the lowstand system tract composed of the giant thickbasin fan, the sequence Ⅲ_3 was followed by the formation of a water system tract consisting of lacustrine and retrogressive delta sedimentary systems, followed by the filling of terrigenous debris Based on the sedimentary characteristics of the interior sediments of the basin, Because of its thick mudstone, rich organic carbon source rock and regional caprock, the water-system system tract is characterized by its good permeability and permeability to sandstones. Central Sichuan and Northwest Sichuan are mainly composed of Ⅲ1 sequence lowstand system tract, followed by Ⅲ2 sequence lowstand system tract, while the eastern part of Sichuan and southern Sichuan are dominated by Ⅲ3 sequence highstandard system tract. It shows that the distribution of natural gas reservoirs changes from predominantly lowstand system tract of the second member of Xujiahe Formation to upperstand system tract of the fifth member of Xujiahe Formation, favoring the trend of eastward migration of the reservoir facies.