西湖凹陷古近系碳酸盐阴极发光特征分析

Cathodeluminescence characteristics and analysis of carbonate cements in Xihu Sag

王春梅 黄思静 裴昌蓉 郜晓勇 王庆东

成都理工大学沉积地质研究院，四川 成都 610059 大庆油田有限责任公司勘探开发研究院，黑龙江 大庆 163712

西湖凹陷是东海陆架盆地中主要的含油气凹陷之一，该区域最重要的自生矿物是碳酸盐胶结物，对储层的影响至关重要，其主要类型为方解石、铁白云石和菱铁矿。根据碳酸盐矿物阴极发光的特征，结合其碳、氧同位素特征研究了该区碳酸盐矿物的形成环境和成岩特征，方解石是在相对较晚的成岩阶段沉淀的，而铁白云石的胶结作用是在较早的成岩阶段，菱铁矿也是早成岩阶段的产物。

Carbonate cements are the most abundant authigenic minerals in the Palaeogene sandstones in Xihu Sag,which is one of the
main petroliferous sags in shelf basin of East Sea. Calcite, ankerite and siderite are the main minerals in carbonate cements. The
diagenetic analysis of carbonate cements are based on the cathodeluminescence characteristics, carbon and oxygen isotope analysis.
It is concluded that calcite is precipitated during later diagenesis stage and the cementation of ankerite and siderite happens during
the earlier diagenesis stage.