海底油气输送管道腐蚀缺陷评价研究

发布时间：2018-01-15 16:46

本文关键词：海底油气输送管道腐蚀缺陷评价研究　出处：《西安建筑科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：石油天然气的管道运输是我国五大运输产业之一,在国民经济中有着非常重要的地位,属于物流运输的范畴,被称为“能源血脉”。近几年,随着海洋油气田在我国的开发,海底输送石油天然气管道的腐蚀风险问题越来越突出,导致事故的数量明显上升。海底腐蚀管道一旦发生失效事故,不但影响整个油气管道运输的生产运营还会给国家社会造成很大的经济损失。开展海洋油气管道腐蚀失效分析,对保障管道的安全运行具有十分重大的意义。因此,本文针对海底腐蚀管道的风险失效模式和可靠性评估展开研究,具体工作内容如下:1)首先分析海底管道环境,总结发生腐蚀的主要原因;阐述三种防止腐蚀发生的方法及原理:阴极保护原理法、管线涂层法和内部腐蚀缓冲剂法。2)在查阅国内外文献的基础上总结评估海底腐蚀管道剩余强度的五种方法:ASME-B31G、DNV-RP-F101、PCORRC方法、API597准则以及有限元法,并对五种方法的优缺点进行比较分析。3)研究基于外压和内压模型缺陷的腐蚀管道系统可靠性,本文采用三种模型来评价海底腐蚀管道的可靠性,分别是伽马模型、逆高斯模型、几何布朗模型。以上面所述三种模型为基础,本文进行了基于时间的同质高斯过程(HGP)增长模型的可靠性的计算和分析,并采用两个在役管段的实测数据进行腐蚀缺陷分析。模拟仿真阶段运用蒙特卡洛法对数据进行预处理,并计算海底管道的失效概率,最后判断管段可能的失效模式:小泄漏、大泄漏、破裂。4)根据海底管道环境复杂性,建立基于海底管道的腐蚀模型并进行剩余强度评价。首先研究并分析了基于CO2的腐蚀缺陷预测模型及其影响因素,然后在现有准则的基础上对管道腐蚀特性进行比较,最后采用参数修正的评价标准预测腐蚀管道剩余强度。5)在腐蚀管道剩余强度下,基于安全系数法准则考虑管道轴向载荷和环向载荷作用,提出了不规则缺陷在抗内压、抗挤压和抗拉强度作用下的极限承载能力,结合安全系数法评价规则进行安全性比较,分析腐蚀强度大小,然后根据腐蚀强度大小确定应该采取哪种决策(进行管道更换或维修),以确保海底管道安全运营。
[Abstract]:Pipeline transportation of petroleum and natural gas is one of the five major transportation industries in China. It has a very important position in the national economy and belongs to the category of logistics transportation, which is called "energy blood" in recent years. With the development of offshore oil and gas field in China, the problem of corrosion risk of submarine oil and gas pipeline becomes more and more serious, which leads to the increase of the number of accidents. It will not only affect the production and operation of oil and gas pipeline transportation, but also cause great economic losses to the country and society. The corrosion failure analysis of offshore oil and gas pipeline is carried out. It is of great significance to ensure the safe operation of pipeline. Therefore, the risk failure mode and reliability evaluation of submarine corrosion pipeline are studied in this paper. The concrete work contents are as follows: (1) first, analyze the environment of submarine pipeline and summarize the main reason of corrosion; This paper describes three methods and principles of preventing corrosion: cathodic protection principle. Pipeline coating method and internal corrosion buffer method. 2) on the basis of consulting domestic and foreign literature, five methods to evaluate residual strength of submarine corrosion pipeline: ASME-B31G are summarized. DNV-RP-F101 / PCorRC method includes API597 criterion and finite element method. The reliability of corrosion pipeline system based on the defects of external pressure and internal pressure model is studied. Three models are used to evaluate the reliability of submarine corrosion pipeline. Based on the above three models, the reliability of the time-based homogeneous Gaussian process (HGP) growth model is calculated and analyzed. In the simulation stage, Monte Carlo method is used to preprocess the data, and the failure probability of submarine pipeline is calculated. Finally, the possible failure modes of the pipeline segment are determined: small leakage, large leakage, rupture. 4) according to the complexity of the submarine pipeline environment. The corrosion model based on submarine pipeline is established and the residual strength is evaluated. Firstly, the corrosion defect prediction model based on CO2 and its influencing factors are studied and analyzed. Then the corrosion characteristics of pipeline are compared on the basis of existing criteria. Finally, the residual strength of corroded pipeline is predicted by parameter modified evaluation standard. 5) under the residual strength of corroded pipeline. Based on the criterion of safety factor method, the ultimate bearing capacity of irregular defects under the action of internal pressure, compression and tensile strength is proposed. Combined with the safety factor method to evaluate the rules of safety comparison, analysis of the size of corrosion strength, and then according to the size of corrosion strength to determine what kind of decision (pipeline replacement or maintenance). To ensure the safe operation of submarine pipelines.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE988.2

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