川西前陆盆地的盆地演化、盆地结构和相对稳定的斜坡构造有利于深盆气的形成和聚集。上三叠统为海陆过渡相和陆相湖盆沉积 ,以三角洲沉积为主的砂体十分发育 ,晚侏罗世中期至早白垩世末期储层开始致密化 ,早白垩世以后储层进入超致密阶段 ,但对于深盆气仍是十分有效的储层。砂体的上覆和下伏层均为暗色泥岩夹薄煤层的气源岩 ,因此对深盆气的聚集和富集成藏十分有利。煤系气源岩分布广、厚度大、生气潜力高、热演化程度高 ,从而为川西坳陷深盆气的形成提供了充足的气源。在早白垩世—晚白垩世中期 ,源岩进入生气高峰 ,为深盆气形成的重要时期 ,造成孔隙中流体体积急剧膨胀 ,引起川西区处于超压环境。喜山运动后盆地大范围仍处于水动力交替停滞带 ,上三叠统深盆气藏大面积具有整体封存条件。因此 ,上三叠统形成了一个几乎覆盖全盆地的特大型深盆气藏。通过对深盆气藏的主控地质因素的分析 ,可将川西坳陷划分为深盆气分布区、气水过渡带和上倾含水区(常规气藏分布区 )等三个区带。从全盆地看 ,气水分布具有明显的倒置关系 ,深盆区内气水分布不受构造控制 The basin evolution, basin structure and relatively stable slope structure of the western Sichuan foreland basin are favorable for the formation and accumulation of deep basin gas. The Upper Triassic sediments are transitional facies and continental lacustrine sediments. Sediments mainly composed of deltaic sediments are well developed. Reservoirs began to densify from the middle of Late Jurassic to the end of Early Cretaceous. After Early Cretaceous, the reservoirs entered the ultra-tight stage , But still a very effective reservoir for deep basin gas. The overlying and underlying layers of the sand body are all gas source rocks of the dark mudstone with thin sandstone and thin coal seam, so it is very favorable for the accumulation and enrichment of deep basin gas. Coal measures gas source rock is widely distributed, thick, high potential for gas generation, high degree of thermal evolution, so as to provide sufficient gas source for deep basin gas formation in western Sichuan depression. During the Early Cretaceous - Late Cretaceous, the source rocks entered the peak of gas generation, which is an important period for the formation of deep basin gas. As a result, the volume of fluid in the pores expanded rapidly and caused the over-pressure environment in the western Sichuan. After the Himalayan movement, the basin is still in a wide range of stagnant zones of hydrodynamic alternation. The large reservoirs of the Upper Triassic deep basin gas reservoirs have the conditions of overall sealing. Therefore, the Upper Triassic formed a very large deep basin basin that covered almost the whole basin. Through the analysis of dominant geologic factors in deep basin gas pools, the western Sichuan depression can be divided into three zones: deep basin gas distribution zone, gas-water transition zone and updip zone (conventional gas reservoir distribution). From the perspective of the whole basin, the gas-water distribution has a significant inversion relationship, and the distribution of gas and water in the deep basin is not controlled by tectonics