酒东盆地营尔凹陷古湖泊水介质研究

在我国西部相当数量的中新生界盆地中，发育半咸水－咸水的沉积，水介质条件决定了这类盆地中碳酸盐储层的形成、发育和分布．因此，对于这类湖盆古水介质的恢复，具有十分重要的现实意义．以酒东盆地营尔凹陷为例，利用稳定同位素、微量金属元素和生物标志化合物参数等方法，综合分析了中生界湖盆的古水介质条件．根据中生界地层古水介质相对盐度和岩性等特征，把古湖盆分为正常湖泊和咸化湖泊两种类型．通过各种方法的综合分析可以看出，整个营尔凹陷南、北部的中生代的沉积水介质是比较一致的，基本上为微咸水到半咸的水介质条件，其中偶夹淡水河流相沉积．以下白恶统中沟组沉积水介质盐度最大，这一层段也是碳酸盐岩最为发育的层段，是碳酸盐岩储层勘探的有利目标．

The Study of the Lacustrine Water Medium in Yinger Sag,Jiudong Basin

Brackish and marine lacustrine deposits were developed in many Mesozoic and Cenozoic basins in West China.The water medium condition determines the formation,development and distribution of carbonate reservoirs in these basins.It is important to rebuild up the medium condition for the exploration of the carbonate reservoirs.The medium condition of Yinger Sag is synthetically analysed according to the analysis data of stable isotopes,microelements and biological markers.The result shows that the water medium conditions of the deposits in the north and south of Yinger Sag are identical,which are brackish ones.According to the relative salinity,lithology and other characters of the medium in Mesozoic formations,the lacustrine basins can be divided into two types of normal and marine ones.The salinity of the deposits in Lower Cretaceous Zhonggou formation is hightest,where carbonate rock are well developed.They are favorable exploration targets.