Internal corrosion is recognized as a serious treat in offshore pipeline services which are supposed to transport vast quantities of oil and natural gases over many long and complicated subsea routes. This paper aims to present a new approach for reliability evaluation of pipelines against corrosion using finite element simulation. In this process the effective random variables are selected by an efficient sensitivity analysis named Tornado Diagram Analysis. Afterwards, a combination of Latin Hypercube Sampling method along with Simulated Annealing technique is used to generate the random simulations which represent the existent epistemic uncertainties. Each realization of this simulation matrix is introduced into the numerical model as the necessary inputs to evaluate the probabilistic responses of the corroded pipeline from linear behavior to failure limit state. This methodology is implemented on a sample offshore pipeline and its results indicate that the maximum Von-Mises stress at all the internal pressure levels follows lognormal distribution. Additionally, as per the findings of this study, the deterministic analysis appears to predict the internal pressure corresponding to the failure limit state conservatively and, therefore, may lead to less remaining life and capacity for corroded pipelines. According to the estimated failure fragility curve, the failure probability of the aforementioned internal pressure level is around 65%.

内部腐蚀被认为是海上管道服务中的一种严重问题，这些服务应该在许多长而复杂的海底路线上运输大量石油和天然气。本文旨在提出一种使用有限元模拟评估管道抗腐蚀可靠性的新方法。在此过程中，有效的随机变量通过名为 Tornado Diagram Analysis 的有效灵敏度分析来选择。之后，结合拉丁超立方抽样方法和模拟退火技术来生成代表现有认知不确定性的随机模拟。该模拟矩阵的每个实现都被引入到数值模型中，作为评估腐蚀管道从线性行为到失效极限状态的概率响应的必要输入。该方法在一个海上管道样本上实施，其结果表明所有内部压力水平下的最大 Von-Mises 应力遵循对数正态分布。此外，根据本研究的结果，确定性分析似乎保守地预测了与故障极限状态相对应的内部压力，因此可能会导致腐蚀管道的剩余寿命和容量减少。根据估计的失效脆性曲线，上述内压水平的失效概率在65%左右。该方法在一个海上管道样本上实施，其结果表明所有内部压力水平下的最大 Von-Mises 应力遵循对数正态分布。此外，根据本研究的结果，确定性分析似乎保守地预测了与故障极限状态相对应的内部压力，因此可能会导致腐蚀管道的剩余寿命和容量减少。根据估计的失效脆性曲线，上述内压水平的失效概率在65%左右。该方法在一个海上管道样本上实施，其结果表明所有内部压力水平下的最大 Von-Mises 应力遵循对数正态分布。此外，根据本研究的结果，确定性分析似乎保守地预测了与故障极限状态相对应的内部压力，因此可能会导致腐蚀管道的剩余寿命和容量减少。根据估计的失效脆性曲线，上述内压水平的失效概率在65%左右。确定性分析似乎保守地预测了与故障极限状态相对应的内部压力，因此可能导致腐蚀管道的剩余寿命和容量减少。根据估计的失效脆性曲线，上述内压水平的失效概率在65%左右。确定性分析似乎保守地预测了与故障极限状态相对应的内部压力，因此可能导致腐蚀管道的剩余寿命和容量减少。根据估计的失效脆性曲线，上述内压水平的失效概率在65%左右。