川西北雷口坡组储层原生孔隙内胶结物研究

A STUDY ON CEMENT IN PRIMARY PORE OF THE LEIKOUPO FORMATION RESERVOIR IN THE NORTHWEST OF SICHUAN BASIN

根据四川盆地西北部中三叠统雷口坡组野外剖面及钻井岩心的宏观观察,借助薄片、阴极发光、电子探针和矿物包裹体等配套资料,研究了雷口坡组储层段亮晶颗粒白云岩和蓝绿藻粘连白云岩内胶结物的结构、特征和组合形式,分析了成岩环境与储集空间的关系,指出原生粒间孔和藻粘结“格架”孔内6种不同类型的亮晶胶结物是4期不同成岩环境的产物,其在产状、矿物学、地球化学等特征和组合形式上具有较大的差异,对储集空间的影响的差异也较大。

According to the macro-observation of the outcrop sections and drilling core of Leikoupo formation of Middle Triassic in northwest Sichuan basin, and the analysis of such supporting materials as thin-section, cathode luminescence, electron microprobe and mineral inclosure, the author makes a comparatively deep study of the structure, characteristics and composition forms of the cement in the sparry grain dolomite and the blue green algae agglutinate dolomite of the Leikoupo formation reservoir, and analyzes the diagenetic environment and the reservoir space. The six different types of the sparry cement in the protosomatic intergranular hole and the algae agglutinate ramework bore are the outcome of different the diagenetic environmen of four periods, and they vary greatly in the characteristics and composition form of the attitude, mineralogy, geochemistry and others, and as well, in their influence on the reservoir space.