Abstract: There is enormous resources potential in the Xujiahe Formation of Sichuan Basin. Owing to the tight reservoir, the fault-fracture bodies have high and unstable hydrocarbon production, as well as limited reserves scale; the tight sandstone reservoirs have low production, and cannot achieve benefits and efficiency, although with large reserves. In order to solve the key problems that limit efficient exploration, i.e., high production, stable production and reserves scale, the new prospecting idea for tight sandstone gas carrier beds has been formed by integrating the exploration ideas for conventional natural gas in reservoirs and shale gas from source rocks. Specifically, the paper establishes the accumulation model of "dual source hydrocarbon supply, transportation by fault-fracture bodies, composite hydrocarbon accumulation" for tight sandstone gas, and also clarifies the hydrocarbon enrichment and high production laws of "spatiotemporal superposition of structure-transportation for controlling reservoir enrichment, effective fracture controlling production in later period, composite combination of source rocks, low-permeability matrix reservoirs and carrier beds for controlling stable production". Guided by the accumulation models for tight sandstone gas carrier beds, as well as the hydrocarbon enrichment and high production laws of tight sandstone gas, 15 wells deployed in the Hexingchang area of western Sichuan depression achieved high yield, thus solving the problem of "rich resources without reserves, large reserves with low production, high production without gas fields" in Xujiahe Formation, Sichuan Basin. Additionally, the field with the proven reserves of 100 billion cubic meters was built in Hexingchang area, western Sichuan depression. On this basis, the efficient exploration and development of ultra-low permeability tight sandstone gas reservoirs in the Xujiahe Formation of western Sichuan depression has been achieved. These achievements have important guidance significance for the efficient exploration and development of tight sandstone gas reservoirs in Sichuan Basin and similar sedimentary basins.

Key words: accumulation models, enrichment and high production regularities, tight sandstone gas carrier bed, Triassic Xujiahe Formation, western Sichuan depression, Sichuan Basin

摘要： 四川盆地须家河组资源潜力大,长期以来由于储层致密,断缝体高产难稳产,储量规模有限,致密砂岩层产量低,有储量无效益。为了解决"高产、稳产、规模"3个制约效益勘探的关键问题,融合以储层为勘探对象的常规天然气、以烃源岩为勘探对象的页岩气的勘探思路,形成了致密砂岩气输导体勘探新思路,建立了"双源供烃、断缝砂输导、复合成藏"的成藏模式,明确了"构造-输导体时空叠合控富、晚期有效裂缝控产、烃源岩-低渗透基质储层-输导体复合控稳"的富集高产规律。以致密砂岩气输导体成藏模式及富集高产规律为指导,在川西坳陷部署实施的15口井均获高产,破解了四川盆地须家河组长期以来存在的"有资源无储量、有储量低产量、有产量无气田"的难题,落实了川西坳陷合兴场地区千亿立方米级探明储量阵地,实现了川西坳陷须家河组致密砂岩气藏高效勘探开发,对四川盆地乃至同类型沉积盆地致密砂岩气藏效益勘探开发都具有重要指 导意义。

关键词: 成藏模式, 富集高产规律, 致密砂岩气输导体, 三叠系须家河组, 川西坳陷, 四川盆地