不规则盐穴储气库气垫回溶修复机理与过程控制研究

Due to the deep buried depth and complicated geological condition, plenty of irregularly shaped caverns were created during leaching for salt cavern gas storage. The cavern shape irregularity needs to be repaired, for it greatly threatens the stability and capacity of the cavern. Application base researches will be performed in this project, aiming at the principle exploration and process control of cavern repair by re-leaching under natural gas. Visual laboratory experiments will be carried out to explore the fluctuation pattern of gas-brine interface. The prediction model of the depth of gas-brine interface in complicated geological conditions will be established. Cavern repair simulation experiments will be performed. The brine flow field distribution will be obtained with Particle Image Velocimetry (PIV) system. A prediction model will be set up to predict the real-time boundary of the irregularly shaped salt cavern during re-leaching. Methods and rules will be discussed to determine the controlling parameters of the dissolution of heterogeneous salt formation, the upper & lower depth limit of gas-brine interface, the adjusting speed of the depth of gas-brine interface, and the controllable technical parameters in the cavern repair process. More efficient and accurate numerical solution methods will be explored for the prediction model of the cavern repair process. A computer program of the shape repair simulation of salt cavern gas storage will be developed and applied in the field tests. The outcomes of this project will provide fundamental theories and methods for the shape repair of irregular salt cavern, which has important reference value for the safety of salt cavern gas storages.

盐穴地下储气库埋深大、地质条件复杂，且采用“水溶盐”的非人工方式开挖，往往形成大量形状不规则的盐穴，若不加以修复，将严重影响储气库运行安全，本项目围绕以天然气为阻溶剂的回溶修复机理与过程控制开展应用基础研究。开展气液界面控制模拟实验，探索气液界面的波动规律，建立复杂回溶工况下气液界面深度的实时预测模型，揭示气液界面波动的不利影响；开展回溶过程流场分布PIV测试，以及回溶修复模拟实验，建立修复过程中不规则边界的动态预测模型；研究非均质盐层溶解控制参数的确定方法，研究气液界面上下限深度的确定准则，研究气液界面上下调整速度的动态设计准则，形成一套回溶修复过程可控技术参数的确定准则和方法；研究回溶修复模型的高效高精度数值求解方法，研发数值计算程序，形成回溶修复模拟设计软件，并通过工程应用修正。项目成果将为不规则盐穴的修复提供基础理论和方法，对于保障我国盐穴储气库的安全运行具有重要参考价值。

不规则盐穴严重影响地下储气库运行安全，必须加以修复后才能使用。本项目围绕以天然气为阻溶剂的回溶修复机理与过程控制，开展了应用基础研究。完成了气液界面控制室内模拟实验，建立了复杂回溶工况下气液界面深度的实时预测模型，研究发现气液界面波动对修复的不利影响在工程可控范围内；开展了回溶过程流场分布PIV测试和回溶修复模拟实验，建立了修复过程中盐腔不规则边界的动态预测模型；提出了非均质盐层溶解控制参数的确定方法，气液界面上下限深度的确定准则，以及气液界面上下调整速度的动态设计准则，形成了一套回溶修复过程可控技术参数的确定准则和方法；提出了回溶修复模型的高效高精度数值求解方法，研发出数值计算程序，编制出回溶修复模拟设计软件。研究成果应用于金坛和江汉储气库修复工程，并通过工程应用进行了校核修正。研究成果为不规则盐穴的修复提供了关键基础理论和方法，对于保障我国盐穴储气库的安全运行具有重要参考价值。