中文摘要：

通过分析油田气井内高压、高速天然气流动诱发的生产管柱振动,建立了考虑天然气流速、压力、管柱轴向力以及重力的高压气井生产管柱面内振动八方程模型。使用传递矩阵法,系统分析了天然气流动效应和管柱轴向力对管柱固有频率的影响;并求解生产管柱以及弯曲管柱面内振动的固有频率;同时建立了一种近似计算重力管柱固有频率的新方法。通过实例研究表明,随着天然气流速、压力、管柱轴向力等参数的增大,生产管柱固有频率逐渐减小,直至失稳。天然气压力、管柱轴向力以及重力对系统固有频率影响较大;而实际开采过程中天然气流速对系统固有频率的影响较小;弯曲管柱前两阶固有频率随流速增大出现耦合模态颤振现象。

英文摘要：

To analyse the vibration of production strings induced by the high-pressure and high-velocity natural gas in the gas well,the eight-functions model considering the velocity,pressure,axial force and gravity is established,which can describe the in-plane vibration of production strings in the high pressure gas wells. Using the transfer matrix method,the influence on the natural frequency of the string caused by flow effect and axial force of natural gas is systematically analysed,and calculating the natural frequency of the production strings and curve strings,meanwhile establishing a new method to calculate the natural frequency of production strings under gravity approximately. The study demonstrates that with the increasing of velocity,pressure,axial force,and the natural frequency of production strings will decrease until the instability. The effect of pressure,axial force and gravity to the natural frequency is obviously; and the effect of velocity is little; with the increasing of the velocity,the coupled-mode flutter takes place in the first two order natural frequency of curve strings.