四川盆地西部侏罗系储层控制因素差异性分析

Difference analysis of Jurassic reservoir controlling factors in western area of Sichuan basin

通过对岩心及岩屑薄片观察,结合粒度、物性、薄片等分析化验资料,分析了四川盆地西部侏罗系储层差异化控制因素。侏罗系以分流河道砂体和河口坝砂岩为储层,储层物性受控于沉积因素和成岩作用。沉积因素主要通过沉积微相及粒度影响储层物性,由龙门山中段物源控制的粒度较粗的水下分流河道及河口坝长石类砂体物性最佳;成岩作用则控制孔隙演化,沙溪庙组破坏性成岩作用强于蓬莱镇组;沙溪庙组河口坝砂体与蓬莱镇组水下分流河道砂体破坏性成岩作用较弱,溶蚀作用较强,保留了较多的储集空间,为有利的勘探开发目标。

Through the observation of core and cuttings slice, combined with particle sizes, physical properties, thin slice and so on, the controlling factors of reservoir differentiation are analyzed. The Jurassic reservoir consists of distributary channel sand body and mouth bar sandstone, the physical properties of the reservoir are controlled by sedimentation and diagenesis. Deposition mainly affects the physical properties of the reservoir through sedimentary microfacies and grain sizes, the coarse sand distributary channel and estuarine dam have the best physical properties of feldspar sandstone by Longmen mountain provenance body. Diagenesis controls pore evolution, and the destructive diagenesis of Shaximiao formation is stronger than that of Penglaizhen formation. In the sand body of mouth bar from Shaximiao formation and distributary channel sand body of Penglaizhen formation, the destructive diagenesis is weaker while the dissolution of easily dissolved minerals is stronger. After the diagenesis,the reservoir of the sand body of mouth bar from Shaximiao formation and the distributary channel sand body from Penglaizhen formation reserve much reserve space, which is a favorable exploration and development target.