回声法检测盐穴造腔气水界面波形的数值模拟

Numerical simulation on the waveform of nitrogen-brine interface during salt-cavern solution mining measured by echolocation method

回声法检测盐穴造腔气水界面具有操作方便、成本低等特点,能够有效控制腔体形态,然而盐穴造腔过程中环空状况复杂,波形识别难度大,导致回声法检测造腔界面存在精度不高的问题。为准确识别盐腔界面检测波形,首先利用Gambit软件建立了回声法检测盐穴造腔氮气-卤水界面数值模型,再利用Fluent软件数值模拟了回声法检测盐穴造腔氮气-卤水界面波形,给出了环空尺寸固定、缩小、扩大3种条件下的氮气-卤水界面检测波形特征。研究结果表明:在不同环空状态下,压力波曲线各有鲜明特征,由此可以利用回声法对盐穴造腔界面进行精确识别。研究成果对盐穴造腔回声法界面检测具有重要的理论与实践指导意义。

The echolocation method for measuring the nitrogen-brine interface during salt-cavern solution mining is advantageous from the aspects of easy operation and low cost, and it can control the cavern shape effectively. However, its measurement accuracy is not high for the annulus condition in the process of salt-cavern solution mining is complex and the waveform recognition is difficult. To recognize the waveform of nitrogen-brine interface accurately, a numerical model to measure the nitrogen-brine interface during salt-cavern solution mining based on the echolocation method was established by the software Gambit. Then, the waveform of nitrogen-brine interface measured by the echolocation method was simulated numerically by the software Fluent. And finally, the waveform characteristics of the nitrogen-brine interface were obtained for three annulus sizes, i.e., fixed, reduced and enlarged. It is shown that the pressure wave curves have distinct characteristics in different annulus states, so based on the characteristics, the nitrogen-brine interface during salt-cavern solution mining can be measured accurately by means of echolocation method. The research results can be used as the theoretical and practical guidance for the interface measurement of salt-cavern solution mining by the echolocation method.