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为保障油气管道安全运营,需研究腐蚀管道寿命的可靠性。首先基于管道失效机理,采用步降应力加速寿命试验(SDSALT)方法,获得不同温度下腐蚀率样本;其次利用加速因子和逆幂律加速方程建立数据折算模型,将腐蚀率样本转换为应力作用失效时间并截尾抽样后作为输入,求得含未知参数的准样本;然后通过准样本估计Weibull分布的3个参数,进而得到以温度和时间为自变量的管道可靠性函数;最后以H_2S/CO_2环境中运营的N80管道为例,验证所建腐蚀管道寿命预测方法的可靠性。结果表明,该方法大幅缩短试验时间,对管道寿命预测准确,并分析出管道可靠性的降低速度随温度和时间的增加先增大后减小,可应用于管道的适用性评价。
To ensure the safe operation of oil and gas pipelines, the reliability of corrosion pipeline life needs to be studied. Firstly, based on the failure mechanism of pipelines, SDSALT method was used to obtain the corrosion rate samples at different temperatures. Secondly, the data conversion model was established by accelerating factor and inverse power-law acceleration equation, and the corrosion rate samples were converted into stress failure Time and truncated sampling as input, the quasi-sample with unknown parameters is obtained. Then the quasi-sample is used to estimate the three parameters of Weibull distribution, and then the pipeline reliability function with temperature and time as independent variables is obtained. Finally, H 2 S / CO 2 The N80 pipeline operating in the environment is taken as an example to verify the reliability of the method for predicting the life of the corroded pipeline. The results show that this method can significantly shorten the test time and predict the life of the pipeline accurately. It is also analyzed that the decreasing speed of pipeline reliability first increases and then decreases with the increase of temperature and time, which can be applied to evaluate the applicability of the pipeline.