【摘要】 基于钻井和地震资料,通过恢复川西坳陷须家河组须二段以来的沉积厚度得到须二段顶界面隆坳格局变迁过程。结合钻井成果和流体包裹体分析技术阐明了须二段天然气的成藏模式和成藏过程。研究表明川西坳陷须家河组须二段顶界面的古构造地貌发生了明显的隆坳格局变迁,现今坳陷中部的孝泉—丰谷构造带经历了宽缓斜坡—坳陷—隆起的演化过程,鸭子河构造经历了深坳到高隆的演化过程。川西坳陷须二段古隆起不具有常规控藏的特征,天然气早期"封闭"在鸭子河坳陷内,表现出深盆气特征。后期的构造抬升和隆坳演化及其派生的裂缝破坏了深盆气藏的稳定平衡状态,使得天然气发生侧向运移形成"连续分布、甜点富集"的现今形态。更多还原

【Abstract】 Based on drilling information and seismic data,and through the restoration of deposit thickness since the second member of Xujiahe Formation(T3x2) in the middle western Sichuan depression,the uplift-depression framework evolutionary process is reconstructed.Combined with drilling results and fluid inclusion analysis technique,the paper illustrates the gas accumulation pattern and process of T3x2.The results show that the palaeotectonic physiognomy underwent apparent changes of configuration of the uplift-depression.The present Xiaoquan-Fenggu structural zone in the middle Chuanxi depression went through the evolution from wide gentle slope to depression,and eventually to uplift.While the evolution of Yazihe zone was from deep depression to high uplift.The palaeo-uplift of T3x2 did not play the controlling role for the conventional reservoir.The gas,sealed in the Yazihe palaeo-depression because of early densification of reservoir,was charactered by deep basin gas.The later tectonic uplift and uplift-depression evolution as well as induced fractures break the steady state of the deep basin gas,and caused gas lateral migration,eventually forming the present pattern,that is "continuous distribution & sweet point enrichment".更多还原