盐穴储气库造腔管柱失稳不仅会降低造腔作业效率,影响造腔质量,还会造成管柱起出困难、造腔失败。基于现场盐穴造腔工艺流程,在建立造腔管柱振动控制方程和管内流体运动方程的基础上,采用ANSYS Fluent商业软件实现了造腔管柱数值求解。借助江汉油田现场M实例井参数,采用相似原理,设计了造腔管柱振动模拟实验台架,测得实验数据,与数值仿真模型计算结果对比,验证了数值仿真模型的正确性。探究了注入流量对造腔管柱振动失稳的影响规律,发现注入流量越大,造腔管柱的初始位移量越大,管柱易发生大变形,引起失稳破坏,在满足造腔施工进度要求时尽量降低造腔管内水流的流速,对于防范造腔管柱静力屈曲或混沌运动失稳具有重要意义。所得结论为造腔施工参数选取提供了理论依据。

The instability of the cavity-making string of the salt cavern gas storage will not only reduce the efficiency of the cavity-making operation, but also affect the quality of the cavity, and even cause the difficulty in pulling out the string and the failure of the cavity. The vibration control equation and fluid motion equation of cavity making string are established by matching the process flow of salt cavern gas storage. The numerical solution of cavity making string is realized using ANSYS Fluent commercial software. According to the field M well parameters of Jianghan oil field and the similarity principle, a vibration simulation test bench for cavity making string is designed. The experimental data are compared with the calculation results of the numerical simulation model, and the correctness of the numerical simulation model is verified. The effects of injection flow rate on the vibration instability of the cavity making string are investigated. It is found that the larger the injection flow rate is, the greater the initial displacement of the cavity making string is, and the larger the deformation of the string is, which will cause instability. It is very important to reduce the flow velocity in the cavity-making pipe as far as possible while meeting the cavity-making construction schedule, so as to prevent the static buckling or chaotic motion instability of the cavity-making pipe string. The conclusions obtained provide a theoretical basis for the selection of cavity-making construction parameters.