四川盆地普光气田须家河组四段储集层特征

Characteristics of Xujiahe Member-4 Reservoir of Upper Triassic in Puguang Gas Field,Sichuan Basin

随着普光气田海相地层天然气勘探的逐步深入,在陆相地层也发现有较多的天然气显示。通过岩心、薄片及测井资料的综合分析,对上三叠统须家河组四段储集层特征进行了探讨。认为该组储集岩类主要为辫状河三角洲沉积的岩屑砂岩,其次为长石岩屑砂岩,储集空间以次生粒间孔为主,次为剩余原生孔隙;压实作用和胶结作用是破坏储集层储集性能的主要因素,而溶蚀作用对储集层储集性能起到改善作用。水下分流河道和河口坝是储集性能较好的沉积微相,其次为分流河道微相,是下一步勘探开发的重点目标。

With in-depth exploration of natural gas in marine strata in Puguang gas field of Sichuan basin, more and more gas shows are found in its continental strata, of which the member-4 reservoir of Xujiahe formation of the Upper Triassic has become the succeeding layer of the major productivity in future in this area. Based on the core, thin-section and well logging data analysis, the characteristics of this reservoir were discussed. Lithology of the reservoir is dominated by lithic sandstone of braided river delta sediment, followed by feldspathic lithic sandstone, and reservoir space is given priority to with secondary intergranular pores, followed by remained primary pores. Compac- tion and cementation are main factors to destroy the reservoir quality rather than dissolution. The underwater distributary channel and mouth bar are sedimentary microfacies with good reservoir property, next to distributary channel microfacies, which are key targets for next exploration and development in the area.