盐穴储气库气卤界面光纤式检测

Optical fiber measurement on gas-brine interface in salt-cavern gas storage

盐穴储气库从建成到投产运行需要经历注气排卤阶段,气卤界面检测与控制是注气排卤的关键技术,现有检测方法检测成本高、不能连续检测,为此提出光纤式界面检测技术。该技术利用分布式光纤测试技术,通过井下光纤测量温度变化,根据温度曲线拐点判断气卤界面的位置,操作简单、探测范围广、监测成本低、能连续测量井下气卤界面位置。将该方法应用于工程实际,并与现有检测方法进行对比和评估,效果良好,其不仅可应用于盐穴储气库注气排卤阶段,还可在氮气阻溶、天然气阻溶造腔过程中使用,具有广阔的应用前景。

Gas injection and brine discharge is an indispensable stage for the construction and operation of salt-cavern gas storage, and the measurement and control of gas-brine interface is the key technology of gas injection and brine discharge. The existing measurement methods cannot do the measurement continuously and their cost is high. To solve these problems, an optical fiber interface measurement technique was developed in this paper. The distributed optical fiber measurement technique is adopted in this technology. The temperature is measured with the downhole optical fiber, and the location of the gas-brine interface is judged according to the inflection point of the temperature curve. This method is advantageous with simple operation, wide detection range, low monitoring cost and continuous measurement. In the practical engineering application, this optical fiber interface measurement technique is proved reliable when compared and evaluated with the existing measurement methods. It can be used not only in the gas injection and brine discharge of salt-cavern gas storage, but also in the process of solution mining under nitrogen and gas, so it has wide application prospect.