油气田水无机阴阳离子含量分析方法的选择及应用

油气田水分析项目复杂,采用的分析方法较多,主要分为手工操作分析与仪器分析。手工操作分析主要有化学滴定法、重量分析法、计算法等,其步骤繁琐,分析周期长,多数水样颜色较深,干扰因素多,滴定终点难以判识,误差大。仪器分析主要有离子色谱法、光谱法、自动电位滴定法等。相对于手工操作分析,仪器分析更为快速准确,但是大型仪器设备及配套的气瓶不方便携带到现场。为确保采用不同方法测定数据的准确性,详细探讨了各分析方法的利弊及各方法的兼容性,通过水分析比对研究,对于正常地层水,化学法与仪器分析法基本兼容。仪器分析的引入刷新了对地层水新的认识,根据水分析数据甄别地层水的方法为油气勘探开发生产提供了有力的地层水地球化学依据。

Selection and application of analysis methods of inorganic anion and cation content in oil and gas field water

The oil and gas field water analysis project is complex and has many analysis methods. It is mainly divided into traditional chemical analysis and instrumental analysis. The traditional chemical analysis includes titration method, gravimetric method and calculation method, which are cumbersome in steps and long time in period. And the titration end point is difficult to recognize because of the dark color of some water samples and many other interference factors. All these increase the error of experiment results. Instrumental analysis includes ion chromatography, spectroscopy and automatic potentiometric titration. Compared with traditional chemical analysis, the instrumental analysis method is faster and more accurate, but large-scale instruments and the gas cylinders are not easy to carry on-site tests. In order to ensure the accuracy of data measured by different methods, the advantages and disadvantages of each analysis method and the compatibility of each method are discussed in detail. The experiment result shows that chemical method is basically compatible with instrumental analysis method for formation water. The introduction of instrumental analysis refreshes the new understanding of formation water. The method of identifying formation water based on water analysis data provides a powerful geochemical basis for oil and gas exploration and development.