管道失效判据简析

在外部载荷超过管道所能承受范围时管道即发生失效。通过研究管道在外力作用下的力学性能,有助于确定管道失效时的应力或应变的临界值,根据是取应力还是取应变作为衡量管道失效时的指标,分别有基于应力的失效判据和基于应变的失效判据。合理选用管道失效判据,可以节约管道投资、延长管道使用时间。简介材料应力—应变曲线的一般特征,分析管道基于应力的失效判据和基于应变的失效判据的方法。     

压力设备腐蚀失效案例统计分析

收集整理近年来有关压力容器管道的腐蚀失效案例,并对其进行了归纳与分析.从整体的腐蚀情况来看,应力腐蚀及其它应力作用下的腐蚀失效形式是压力容器管道比较突出的腐蚀失效问题,同时奥氏体不锈钢、碳钢及低合金钢三种材料的腐蚀失效较严重.     

油气管道失效分析与完整性管理

论述了油气管道的失效模式和失效原因,以及完整性管理的概念、流程和关键技术.对失效分析和完整性管理的关系进行了讨论,认为失效分析是油气管道完整性管理的基础;完整性管理是油气管道失效分析的延伸,是全面、科学有效的预测、预防管道失效的措施.     

海洋CO2管道输送技术现状与展望

管道输送是经济高效的CO₂运输方式,海洋CO₂运输是离岸碳捕集、利用与封存(CCUS)产业链的关键环节和规模化开展离岸CCUS工程建设所需的核心技术。本文明晰了我国实施离岸CCUS的优势、典型海洋碳运输情境和海洋CO₂运输方式,剖析了国内外海洋CO₂管道输送的技术与工程概况;从CO₂流体相态及流动安全,沿程腐蚀风险评估、监测及预警,CO₂泄漏实时监测技术,高压CO₂泄放及对环境的影响等方面梳理了海洋CO₂管道输送工艺技术现状;从CO₂管道材料断裂行为及止裂措施、高耐蚀及密封材料、碳钢管道长寿命运行的关键腐蚀控制技术、注采井筒的腐蚀风险评估等方面梳理了海洋CO₂管道材料技术现状。研究认为,加快发展适应海洋CO₂管道输送复杂工况的材料体系、全流程CO₂管道的智慧管理与数字孪生技术、海底CO₂管道全生命周期运行...     

湿H2S环境下耐酸型碳钢管道的氩电联焊焊接工艺的制定

本文以伊拉克某油田项目为例,结合NACE MR0175、NACE RP0472等标准要求,确定了湿H2S环境下碳钢管道的焊接工艺,对试件进行了硬度检验、焊缝化学成分分析、力学性能试验、抗氢致裂纹试验和抗硫化物应力腐蚀开裂试验,各项试验结果均符合要求,并提出了现场焊接技术要点,为湿H2S环境下碳钢管道的焊接提供了工艺保障,为今后类似的石油开采及炼制项目提供参考.     

在役腐蚀管道动态非概率可靠性分析简

 腐蚀失效是压力管道失效的主要形式之一,研究腐蚀管道的可靠性具有重要理论意义和应用价值.在对腐蚀管道可靠性分析时,概率可靠性模型和模糊可靠性模型对于数据信息的要求较高.而在掌握不确定性信息很少情况下,为了充分利用管道的不确定性信息弥补原始数据的不足,可将腐蚀管道可靠性分析中的材料屈服强度、管道直径、缺陷深度和操作压力等不确定参数视为区间变量,基于区间模型建立一种在役腐蚀管道动态非概率可靠性模型,给出了腐蚀管道剩余寿命预测的简便方法.结合工程实例计算与分析,表明了文中所提出方法的可行性和合理性,并在此基础上,分析了管道的壁厚、缺陷深度、实际压力和腐蚀速率这些区间变量的不同变异系数对非概率可靠性指标的影响,分析结果表明非概率可靠性指标对管道壁厚的变异系数最为敏感.     

高含H2S天然气集输管线氢鼓泡失效评价

针对酸性环境下硫化物造成天然气集输管线严重腐蚀开裂的失效现象,根据高含H2S天然气集输管线材质选择、力学性能、显微形貌等综合性能数据结果,对其失效行为进行深入分析和评价。结果表明,在高含H2S、CO2和水等腐蚀介质的集输管线内壁发生腐蚀失效和氢鼓泡的危险性极大,提出产生氢鼓泡现象的影响因素及其预防措施从而指导集输管线的安全运行。     

高含H_2S天然气集输管线氢鼓泡失效评价

针对酸性环境下硫化物造成天然气集输管线严重腐蚀开裂的失效现象,根据高含H2S天然气集输管线材质选择、力学性能、显微形貌等综合性能数据结果,对其失效行为进行深入分析和评价。结果表明,在高含H2S、CO2和水等腐蚀介质的集输管线内壁发生腐蚀失效和氢鼓泡的危险性极大,提出产生氢鼓泡现象的影响因素及其预防措施从而指导集输管线的安全运行。     

高含H2S天然气集输管线氢鼓泡失效评价

针对酸性环境下硫化物造成天然气集输管线严重腐蚀开裂的失效现象,根据高含H2S天然气集输管线材质选择、力学性能、显微形貌等综合性能数据结果,对其失效行为进行深入分析和评价。结果表明,在高含H2S、CO2和水等腐蚀介质的集输管线内壁发生腐蚀失效和氢鼓泡的危险性极大,提出产生氢鼓泡现象的影响因素及其预防措施从而指导集输管线的安全运行。     

城市埋地燃气管道的失效树建立与风险评估

依据失效分析理论,运用演绎法建立了城市埋地燃气管道失效树.通过最小割集和结构重要度分析确定了城市埋地燃气管道失效的主要原因及其相对重要程度.在此基础上,建立了适合我国国情的城市埋地燃气管道风险评估技术体系,包括管道区段的划分、失效可能性评分体系、失效后果评分体系和风险等级划分.     

Pipeline failures in corrosive environments – A conceptual analysis of trends and effects

Pipeline corrosion is a major challenge facing many oil and gas industries today because of the enormous downtime associated with corrosion related failures. Fatigue stress initiation in pipelines has been attributed to corrosion defects whose growth is enhanced by cyclic loading caused by the operating pressure of the transported fluids. This work reviews the concept of oil and gas transmission pipeline failures in corrosive environment by highlighting the corrosion mechanisms, dominant stress corrosion cracking trends, hydrogen induced cracking and predominant models for burst pressure estimation. Fatigue stress failure trends of corroding pipelines were also explained whilst describing some pipeline manufacturing processes that increases the susceptibility to fatigue stress failure. Optimization framework for pipeline integrity assurance against corrosion fatigue failures was also shown to incorporate different steps that includes – strategic policy initiation, policy implementation, information analysis and reviews and implementation actions.     

Pipeline Failure Results from Lightning Strike: Act of Mother Nature?

There are more than 2.5 million miles of oil and gas pipelines in the United States. Approximately 900 failures occurred on hazardous liquid pipelines from 2002 to 2003, and 9% of these failures were attributed to damages due to natural force, which included lightning strikes, among other naturally occurring events. This paper provides a case history in which failure analysis was applied to determine the metallurgical cause of a failure involving a polyethylene-coated hydrocarbon pipeline that leaked as a result of a lightning strike.     

管线钢用自保护药芯焊丝发展概况

自保护药芯焊丝焊接过程无需外加保护气体,焊接速度快,在输油管道等领域得到了广泛的应用。文章介绍了管线钢用自保护药芯焊丝国内外研究进展、自保护药芯焊丝冶金特点、典型的管线钢用焊接材料以及自保护药芯焊丝需要解决的问题。     

Gas transmission pipeline failure probability estimation and defect repairs activities based on in-line inspection data

Degradation of an underground pipeline during its service life leads to reduction of the pipe wall thickness. Periodic in-line inspections are performed by onshore pipelines operators to detect corrosion anomalies and size their depth and width. In the paper, a simple analytical method of burst pressure calculation for a straight pipeline repaired with a composite sleeve was investigated. Repair activities after an in-line inspection of a gas transmission pipeline were considered in this research to assess the pressure of a pipe with a flaw reinforced with a different number of layers of a fiber-based polymer sleeve. Det Norske Veritas criteria and formulation of a limit state function were applied to determine the burst pressure and corresponding failure probability of a pipeline with a large number of single and non-interacting part-wall defects. The Monte Carlo method was selected for estimation of pipeline failure probability and cumulative failure probability due to the external corrosion considering fluid pressure fluctuations in dynamic flow effects with respect to statistical distribution of input parameters were examined in this research. The proposed novel 3-step approach was validated on the real data collected from an onshore high pressure gas pipeline DN 700, MOP 5.5 MPa provided by two magnetic flux leakage inspections repeated at an interval of twelve years. A probabilistic methodology was applied to evaluate the part-wall external corrosion defects and their deterministic linear growth with time and repair activities on gas transmission pipelines were analyzed. The results of this study shall help maintenance engineers solve the problems of an optimal strategy in reliability-based high pressure gas pipelines management.     

Assessment on failure pressure of high strength pipeline with corrosion defects

An accurate prediction on the failure pressure of line pipe is very important in the engineering design and integrity assessment of oil and gas transmission pipelines. This paper analytically investigates the failure pressure of line pipes with or without corrosion defects, and focus on the high strength steels. Based on von Mises strength failure criterion, a classic strength failure criterion, the failure pressure of end-capped and defect-free pipe p_M is theoretically deduced with the strain hardening material. In order to derive a general solution for corrosion defect assessment of high strength pipelines, an extensive series of finite element analyses on various elliptical corrosion defects was performed. Finally, a new formula for predicting the failure pressure of corroded pipe in the material of high strength steels is formulated, based on the FE models and p_M, and is validated using 79 groups of full-scale burst test data, which contain the low, middle and high strength pipeline. The results indicated that the proposed formula for predicting the failure pressure is closely matches the experimental data for the high strength steels.     

Buckling failure mode analysis of buried X80 steel gas pipeline under reverse fault displacement

High strength steel pipeline is widely used in long distance transportation of natural gas. These pipelines are vulnerable under active faults in strong seismic areas. The buckling failure modes of high strength X80 gas pipeline crossing reverse fault were analyzed systematically in this paper. Based on the nonlinear finite element method, a pipe-elbow hybrid model was developed for buckling failure analysis of X80 steel pipeline under reverse fault displacement. The pipe soil interaction relationship was simulated by a series of elastic-plastic soil springs. The nonlinearity of pipe material and large deformation were also considered. The non-linear stabilization algorithm was selected due to the convergence of the numerical model. Engineering parameters used in the Second West to East Gas Pipeline in China were selected in this study. Typical features for beam buckling and local buckling failure in the proposed numerical model were derived. Based on a series of parametric studies, the influences of the fault displacement, fault dip angle, pipe wall thickness, buried depth of pipe and soil conditions on the buckling failure modes were discussed in detail. The proposed methodology can be referenced for failure analysis and strength evaluation of pipelines subjected to reverse fault displacement.     

火电机组EH油管道泄漏典型案例分析及防范措施

汽轮机EH油系统管道连接供油系统、危急遮断系统与执行机构构成整个回路,其作为油介质的传输通道,一旦发生泄漏,将直接造成发电机组非计划停运,让企业蒙受巨大的经济效益与社会效益损失。针对某集团公司近期火电机组发生的多起EH油管道泄漏案例,从金属材料角度概括了EH油管道常见的几类失效机制,并结合每个典型案例,对失效分析过程及要点做了简单介绍,重点从技术监督角度提出了治理和防范措施,具体到相应的检查方法和检查内容,切合现场,以供借鉴。     

高钢级管线钢X80的研制与发展

高钢级、大管径已经成为油气输送钢管发展的总趋势.对国外X80管线钢的研制和应用情况进行了总结,介绍了现行几种X80钢管的国际标准以及国外X80钢的实物水平,并对当前国内管线钢的研发现状进行了分析,同时介绍了国内X80管线钢的开发计划和进展情况.     

Failure pressure of medium and high strength pipelines with scratched dent defects

It is very important in engineering design and integrity assessment of pipeline to accurately predict its failure pressure, especially for the pipeline with mechanical damages. This paper numerically investigates the failure pressure of medium and high strength pipelines with scratched dent which is on the outer surface of the pipe. Pipe materials of two different grades are chosen in the analysis which represent medium and high strength steel, respectively. Failure pressure of an intact pipeline with fixed ends is derived analytically. On the basis of the maximum plastic strain failure criterion put forward by previous scholars, failure pressure of finite element models containing dent and scratch defects is determined. Parametric studies are carried out to obtain the influencing rule of the dimensions of dent and scratch. The effects of scratch length and depth on failure pressure with various dent depths are obtained. Finally, a formula is fitted for predicting the failure pressure of pipelines with scratched dents on the basis of finite element results. Compared to burst test data from literature, the proposed formula is proved to be reasonable.     

往复式压缩机管道系统振动分析与控制

针对牙哈作业区中压机组排气管系发生剧烈振动的问题,利用西安交通大学研究开发的管道振动分析软件包PAP,建立管道系统的有效的力学模型,对排气管系的机械固有频率、管道内气体系统固有频率及气流脉动值进行分析计算找到了产生振动的根源,根据分析计算提出了有效解决方案,使管道系统的振动得到了大幅降低。