In view of the fatigue failure of tubing strings by flow-induced nonlinear vibration (FINV) in high-temperature, high-pressure and high-yield (3H) curved gas wells, a three-dimensional (3D) FINV model of the tubing string is established using the micro-finite method, energy method and Hamilton variational principle, and verified by a similar experiment of tubing vibration. Meanwhile, the cumulative damage theory is used to establish the fatigue life prediction method of tubing string combined with the stress response which was determined by the proposed FINV model and the S-N curve of the tubing material (13Cr-L80) which was measured by fatigue test. Thus, the influences of production rate, well trajectory parameters (inclination angle and well section length), as well as the installation position of downhole tools (packer and centralizer) on the fatigue life of the tubing string are systematically analyzed. The results obtained demonstrate that, first, with the increase of production rate, the fatigue life of the tubing string decreases, and the field production allocation should be far away from the sudden production rate which can be determined using the proposed analysis method. Second, in the well trajectory design, the vertical section length should be reduced, while that of build-up section and the angle of stable inclined section should be increased. Third, the packer and centralizer should be placed in the optimal position, which depends on the well structure, downhole tool size, etc. and can be determined using the proposed analysis method. The research results provide a theoretically sound guidance for designing and practically sound approach for effectively improving the fatigue life of tubing string in 3H curved gas wells.

针对高温高压高产（3H）弯曲气井中流致非线性振动（FINV）对油管柱的疲劳破坏，提出了油管柱三维（3D）FINV模型利用微有限法、能量法和哈密顿变分原理建立，并通过类似的油管振动实验验证。同时，结合所提出的FINV模型确定的应力响应和疲劳试验测得的油管材料(13Cr-L80)的SN曲线，利用累积损伤理论建立了油管柱疲劳寿命预测方法。 . 因此，产量、井轨迹参数（倾角和井段长度）的影响，以及井下工具（封隔器和扶正器）的安装位置对油管柱疲劳寿命的影响。得到的结果表明，首先，随着产量的增加，油管柱的疲劳寿命降低，现场生产分配应该远离使用所提出的分析方法可以确定的突然的产量。其次，在井眼轨迹设计中，应减小竖向段长度，同时增大造斜段长度和稳定倾斜段的角度。第三，封隔器和扶正器应放置在最佳位置，这取决于井结构、井下工具尺寸等，可以使用建议的分析方法确定。