四川盆地寒武系储层特征及优质储层形成机理

通过岩心薄片观察、地球化学分析、及晶洞流体充填序列分析,对四川盆地寒武系优质储层形成机理进行研究。研究表明,滩相沉积相带是优质储层形成的基础,膏溶、淡水岩溶与成岩早期大气淡水渗滤溶蚀是寒武系先存孔洞的主要形成机制,而深埋过程中外源侵蚀性流体溶解作用则是扩溶先存孔洞或形成新孔洞的持久动力,适宜的构造位置与弱的流体反应则为先存孔洞保存的先决条件。

Reservoir characteristics and formation mechanism of the high quality Cambrian reservoirs in Sichuan Basin

Based on core observation,thin section identification,geochemical analysis and analysis of inside geode fluid-filling sequence,this paper tries to discuss the formation mechanism of the high quality Cambrian reservoirs in Sichuan Basin.The following results are obtained:shoal facies tract is the foundation of high quality reservoir;gypsum dissolution,fresh-water karstification and meteoric water filtration and dissolution at the early diagenetic stage are the chief mechanisms of the pre-existing vugs in the Cambrian;dissolution of extraneous corrosive fluids in the process of deep burial is the persistent driving force of enlargement of the pre-existing vugs and the formation of new vugs;favorable tectonic position and weak fluid reaction are the prerequisite to the preservation of the pre-existing vugs.