川中地区侏罗系下沙溪庙组浊沸石砂岩储层的发现及意义

Discovery of Sloanite Sandstone Reservoir of Jurassic Xiashaximiao Formation in Central Sichuan Region and Its Significance

通过微观和宏观的研究方法,在川中地区大面积超低渗透储层背景下,发现了下沙溪庙组中下部发育一套相对高孔隙的含浊沸石砂岩储层。砂岩中浊沸石以胶结物形式充填粒间孔隙中,浊沸石含量一般3%?6%,局部可达10%?28%,并发育广泛的次生溶蚀作用,电子显微镜下次生溶蚀孔隙面孔率可达2%?3%。浊沸石次生溶孔是下沙溪庙组最主要的孔隙类型。含浊沸石砂岩厚度大、分布广,其形成与物源、沉积相带有一定关系。进一步研究浊沸石分布、次生溶蚀带分布对预测下沙溪庙组有利储层、油气富集区带具有重要意义。

Based on the macro and micro study methods, a set of relatively high porous sloanite-containing sandstone reservoir is found in the middle and lower parts of Xiashaximiao Formation against the background of super-low permeable reservoirs in large areas in Central Sichuan region. Sloanite in sandstone is packed into intergranular pores in the form of cement. The content of sloanite is generally 3~6 percent and partially as high as 10~28 percent. There is also extensive evolution of secondary solution effect. The facial porous rate of secondary dissolution pore under the electronic microscope may reach 2~3 percent. The sloanite secondary dissolved pore is the most important porous type of Xiashaximiao Formation. The sloanite-containing sandstone has large thickness and extensive distribution. It is formed in relation to the source and sedimentary facies. The further study of sloanite distribution and secondary dissolution zone is of great importance to predicting the favorable reservoirs and oil and gas enriched zones of Xiashaximiao Formation.