柴达木盆地西部狮子沟背斜构造区深部卤水水化学特征及演化分析

近年来的调查工作发现,柴达木盆地西部的一些背斜构造区油田卤水具有储量大、品位高的特点,表现出良好的开发和利用前景。在狮子沟背斜构造区深部有含卤层甚至盐岩层的发现。以狮子沟背斜构造区深层卤水为研究对象,采样测试其离子含量,进而分析卤水的离子比例系数,对其水化学特征、物质来源、演化过程进行分析,研究认为深部卤水主要是盐岩溶解作用形成的,其中不乏有沉积卤水的加入;其演化主要受控于蒸发和溶解的双重作用,同时白云岩化、酸性斜长石的溶解以及中酸性热液的淋滤作用也可能对该区卤水有某种程度的影响。

Hydrochemical Characteristics and Evolutionary Process of Deep Brines from Shizigou Anticline Structure in Qaidam Basin, China

The investigation in recent years found that the oilfield brine from some anticline structures in the western Qaidam Basin was characterized by large reserves and high grade of valuable elements, which shows good prospect of development and utilization. Deep brine aquifer, even salt rocks,were found in Shizigou anticline structure area.In this study,a total of 13 brine samples were collected and analyzed for major and trace ionic contents in order to discuss the hydrochemical characteristics,origin and evolution of the brines.The conclusion includes that solutes of the deep brines of research area is mainly originated from rock salt dissolution and contribution from sedimentary brine is minor.The evolution of brines is mainly controlled by evaporation and dissolution,meanwhile,other processes including the dolomitization,dissolution of acid plagioclase and mixing of acid-neutral hydrothermal fluids also influenced the evolution of the brine.