川中地区寒武系大气田成藏特征及主控因素分析

The Reservoir-Forming Characteristics and Major Controlling Factors of Cambrian Large Gas Field in Central Sichuan Basin

川中地区寒武系发育有目前国内单体规模最大的海相碳酸盐岩大气田——安岳气田，近年来，勘探热度在不断增加。结合四川盆地寒武系区域地质资料以及安岳气田近年来的勘探和研究成果，以戴金星院士提出的大气田成藏理论为指导，分析川中地区寒武系气田的成藏特征，探讨成藏主控因素。研究表明：安岳气田具有低层生气中心、晚期成藏以及古构造聚气滞后等特征。大气田的形成不仅需要裂陷．隆起构造系统奠定优越的物质基础，形成筇竹寺组、龙王庙组等优越的地质条件；还需要时间与空间的有机配置，空间上为下生上储，时间上为晚期聚气成藏，有机质接力生烃；最后在特殊的古环境因素（即寒武纪初期气候变热，冰川消融，海平面发生变化等）催化下，安岳气田才能最终形成并得以保存。

The large gas field, Anyue Cambrian Gas Field developed in central Sichuan Basin has been the largest carbonate gas field in China at present. And its exploration heat has been continuously escalated in recent years. Combined with regional geological data of Cambrian in Sichuan Basin and some latest achievements in Anyue Gas Field in recent years, and guided by the theory of hydrocarbon accumulation in large gas field proposed by academician Dai Jinxing, the reservoir forming characteristics of Cambrian large gas field were analyzed and key controlling factors were discussed. Research shows that Anyue gas field has the following three characteristics such as low gas generating center, hydrocarbon accumulation at the late stage and the delay of gas accumulation in palaeo-structure. The formation of large gas field needs no fractured-depression and uplifted structural system to lay a superior material basis and it needs the superior geological conditions such as Qiongzhusi Formation and Longwanmiao Formation are formed and it also needs an organic configuration of time and space, the oil is generated in the position and stored in the lower position in the space and in time gas is accumulated in the late period, a successive hydrocarbon is generated by organic matter, eventually it is catalyzed by special palaeo-environmental factors （such as the climate becomes hot, glaciers are meltdown and sea level is changed etc.）, therefore Anyue Gas Field is formed and preserved.