米仓山前缘隐伏构造带构造演化与长兴-飞仙关组油气成藏的关系

四川盆地东北部米仓山前缘隐伏构造带油气勘探潜力巨大，但由于构造变形强烈，油气成藏过程复杂，该区的勘探程度一直较低。为此，从构造演化与油气成藏关系入手，分别探讨了峨眉地裂运动、米仓山形成演化与该区上二叠统长兴组-下三叠统飞仙关组油气成藏的关系。分析认为，峨眉地裂运动控制了开江-梁平陆棚的形成，陆棚的形成演化为长兴-飞仙关组油气成藏提供了物质基础和储集空间。运用低温年代学证据，确定米仓山大规模隆升发生在燕山晚期和喜马拉雅期，燕山晚期米仓山开始强烈隆升，基底断裂发生拆离，地层褶皱挠曲变形，且呈前展式向南递进形变；喜马拉雅期再次隆升向南挤压，应力进一步向南传递，低缓部位褶皱变形。进而研究了米仓山形成对其周缘油气成藏具有的明显的控制作用，并将其划分为3个阶段，即古油藏成藏阶段（印支晚期-燕山期早期）、古气藏成藏阶段（燕山中期）和油气藏改造调整阶段（燕山晚期-喜马拉雅期）。最后，指出现今规模气藏主要分布在该区滑脱褶皱带内台缘礁滩储层发育区。

Relationship between tectonic evolution and hydrocarbon accumulation in the Changxing and Feixianguan Fms in the frontal concealed structural zone of Micangshan Mountain, northeastern Sichuan Basin

The frontal concealed structural zone of the Micangshan Mountain, northeastern Sichuan Basin, is a prospective area for oil and gas exploration, but the exploration degree there is still low due to the intensity of tectonic deformation and the complexity of hydrocarbon accumulation process. Beginning with the relationship between tectonic evolution and hydrocarbon accumulation, we discussed the correlations between hydrocarbon accumulation in the Permian Changxing Fm and the Lower Triassic Feixianguan Fm and the Emei taphrogeny and the formation & evolution of the Micangshan Mountain respectively. The Emei taphrogeny controlled the formation of Kaijiang Liangping shelf, which provided the source rocks and reservoir spaces for hydrocarbon accumulation in the Changxing and Feixianguan Fms. On the other hand, low temperature geochronological data revealed that large scale uplifting of the Micangshan Mountain occurred in the Late Yanshan and Himalayan epochs. In the Late Yanshan epoch, the Micangshan Mountain began to strongly uplift, the basement fault decoupled, and the folds experienced flexural deformation of southwards progressive type. In the Himalayan epoch, it uplifted again and compressed southwards, leading to the passing of stress further southwards and deformation of folds in the structural low. The formation of the Micangshan Mountain has strong control on the process of hydrocarbon accumulation in its periphery, which is divided into 3 stages, namely fossil oil reservoir formation (Late Indosinian Early Yanshan), fossil gas reservoir formation (Mid Yanshan), and deformation of oil/gas reservoirs (Late Yanshan Himalayan). Finally, it is pointed out that current large scale gas reservoirs are mainly distributed in reef shoal reservoir strata in the epiplatform of the decollement fold belt.