腐蚀海底管道剩余强度的可靠性评估方法研究

针对常用腐蚀海底管道剩余强度评估方法的局限性,提出一套联合载荷作用下腐蚀海底管道剩余强度评估的方法,通过有限元分析联合载荷作用下腐蚀海底管道的剩余强度,考虑到腐蚀缺陷有关参数的不确定性,以腐蚀管道失效压力和腐蚀速率分析为基础,建立腐蚀管道可靠性极限状态方程,采用蒙特卡罗法计算腐蚀海底管道的失效概率.通过模型计算验证方法的可行性.     

埕岛油田海底管道修复施工技术探讨

考虑到胜利油田埕岛海域海底管线的修复及维护施工难度大,分析埕岛油田浅海区域内海底管道漏点、外管变形及断裂的修复方法,同时对修复的施工工艺进行探讨。     

含有腐蚀缺陷海底管线失效压力研究

腐蚀是引起海底管线破坏的一种重要原因.采用非线性有限元方法,对含有腐蚀缺陷的海底管线进行了内压作用下的极限承载力分析.研究了腐蚀长度、深度、宽度、径厚比对海底管线的破坏机理和对失效压力的影响,提出了含有腐蚀缺陷的受内压作用的海底管线失效压力计算公式.与试验结果及各种规范和方法进行了对比,证明该方法是有效的,为腐蚀海底管线的评估提供了依据.     

原位内涂敷技术在埕岛油田海底管道上的应用

考虑到应用原位内涂敷技术可以对铺设好的管道进行内壁防腐涂层涂敷,达到减少腐蚀、保护管线、延长管线寿命的目的,对埕岛油田已建成的海底管道采用原位内涂敷技术施工工艺,指出施工中应该注意的几个问题.     

轴向长腐蚀管道极限承载力研究

腐蚀是引起海底管道破坏的重要原因之一,其中轴向长腐蚀是海底管道常见的腐蚀形式.文中采用非线性有限元方法,对轴向长腐蚀海底管道进行了内压荷载作用下的破坏机理的研究.并分析了腐蚀长度,腐蚀深度和腐蚀位置对海底管道失效压力的影响.根据有限元分析结果,回归得到适用于轴向腐蚀海底管道极限失效压力的计算公式,并与试验结果吻合较好,为长腐蚀海底管道的评估提供依据.     

海底管道损伤处的修复方法

本文简要分析了海底管道的各种损伤原因,简述了损坏形式及相应的修复方法。海底管道修复可以分为水面焊接修复和水下修复,其中水下修复又有水下干式高压焊接修复、机械联接器修复、水下机械式三通修复、水下环氧树脂套筒修复、法兰修复和外卡修复等修复方法。本文对这几种修复方法的修复过程以及各自优缺点进行了详述。     

施工船舶抛锚作业对海底管道的影响研究

抛锚作业可能会撞击海底管道,这是一种偶然发生的事件,海底管线因碰撞而发生损坏是其面临的主要安全威胁。但是这对于该管道的安全运行造成了一定的破坏与影响。文章中分析了抛锚作业撞击海底管道后所采取的相关措施,以及抛锚作业撞击海底管道的机率,为进一步探讨提高探究海底管道在偶然发生时所带来的影响。     

基于非线性有限元法的海底管道剩余强度研究

考虑腐蚀海底管道材料非线性及几何非线性特点,基于塑性失效准则,采用非线性有限元法建立腐蚀海底管道剩余强度模型,以此预测腐蚀海底管道失效压力。基于非线性有限元法的计算结果,与失效压力准则法进行对比,分析腐蚀缺陷长度、深度、角度及腐蚀位置对失效压力的影响规律。     

某油田海底管道抗电磁干扰腐蚀研究

高压交直流输电工程对周边油气管道的杂散电流干扰问题是近年来国内外关注热点,大量现场案例和研究显示,交流电力电缆会对周边埋地油气管道产生电磁干扰,产生电化学腐蚀.同样,海底管道在一些特定的环境下,也会受到电磁干扰的影响,增加腐蚀风险.文章以渤海油田一条油气混输海底管道为研究对象,在穿越航道区域与海底电缆交叉并近距离并行布...     

海底管道损伤处的修复方法

本文简要分析了海底管道的各种损伤原因,简述了损坏形式及相应的修复方法.海底管道修复可以分为水面焊接修复和水下修复,其中水下修复又有水下干式高压焊接修复,机械联接器修复、水下机械式三通修复、水下环氧树脂套筒修复、法兰修复和外卡修复等修复方法.对这几种修复方法的修复过程以及各自优缺点进行了详述.     

一种具有双重功能的海底挖沟机

水下管道维修前，需要对海床进行基础开挖使管道裸露出来，并在维修点周围形成一定范围的工作面，因此须要使用水下管道维修基础开挖的专用设备——海底挖沟机。在新管线敷设过程中，也需要先对海底实施挖掘开沟，然后进行管道埋设。介绍了一种海底挖沟机，特别是关于一种既能进行海底管道维修基础开挖，又能进行海底管道开沟埋设的具有双重功能的海底挖沟机。     

海底管道巡检船研发设计

简要介绍自主研发设计的"海底管道巡检船"船型的主要技术性能和技术特点。该船定位为国内首艘海底管道巡检船,搭载专业声学探测装置,抗风浪性能良好,能够持久巡线并应急响应,其各项功能均针对渤海海域海底管道运维需求进行设计,能够保障海底管道安全运营,排除隐患以避免或最大限度降低管道泄漏造成的损失。     

水下管道连接器设计研究及应用

随着全球海洋石油天然气开发从浅水走向深水,由于潜水员下潜深度有限,海底油气管道的连接必须通过水下机器人代替潜水员完成此项工作。因此各种管道连接技术也越来越多地应用于海洋石油开发中。水下管道连接器作为一种重要的自动安装连接装置,涉及到机械、液压、材料、防腐、密封等各个方面,具有免潜水员操作、安装便捷、可靠性高等特点,可广泛应用于水下油气管道连接。本文对已成功应用于南海某气田中水下采气树跨接管连接的水平机械式管道连接器和水下管汇发球器连接的垂直液压式管道连接器,从密封结构、导向结构、锁紧结构的设计进行了深入的阐述,并在连接器样机型式试验、产品防腐、水下安装等方面也进行了详细的说明。     

Efficient methods to mitigate SCR-induced walking of short subsea flowlines

Steel catenary riser is a long-established option for subsea projects in deep-water regions. Sustained pulling force of steel catenary risers on subsea flowlines in combination with cyclic thermal load throughout the system lifetime may lead to progressive global axial displacement of subsea pipelines which has been termed as ‘walking’. One of the challenges in the deep-water industry is long-term walking of subsea flowlines in a cumulative manner. Common practice methods for walking mitigation are quite expensive operations. State-of-the-art mitigation strategies are proposed in the paper by means of modifying pipe pieces before the installation operation. Bowed pipe pieces and miter joints are two recommended approaches for walking mitigation. The presented mitigation strategies are relatively cost-effective solutions for the pipe-walking challenge and they are able to considerably cease the potential cyclic walking. Comprehensive FE analyses in ABAQUS software are performed to evaluate the proposed deformed pipelines response subject to two loading conditions. Through-life integrity of the suggested pre-deformed pipeline is assessed in terms of effective axial force, local buckles and excessive axial strains. A comparison of the presented method with conventional techniques shows the effectiveness of the proposed configuration. The proposed methods can significantly reduce effective axial force throughout the subsea pipeline by means of artificially introduced deformations. The cumulative walking of the presented method is practically zero. In addition, the influence of combined triggering mechanisms to the walking phenomenon is assessed when the pipeline is located on a sloping seabed and it is subject to non-uniform thermal loads. A parametric study is performed to improve confidence in design and provide a reasonably practical technique with an optimal shape.     

国外海底管道局部屈曲研究综述

海底管道是海洋油气集输系统中最重要的组成部分之一,从铺设到服役都将承受多种载荷的作用,并可能发生局部屈曲且沿管道传播开来,由此造成严重的后果。海底管道的局部屈曲在管道安全性方面具有重要意义,已成为海底管道设计与评估中重要的内容。详细阐述了国外关于海底管道受外压、弯矩和轴力作用下的局部屈曲研究成果,论述了在单个载荷和多个载荷联合作用下的局部屈曲破坏机理,并提出了未来研究的建议。     

海港锚地布置相关安全距离研究

针对海港锚地与建构筑物和海底电缆管线等的安全距离问题,对沿海各锚地使用管理单位进行调研,将国内外规范中对于锚地布置安全距离的规定进行对比分析,针对已有的船舶走锚事故报告并结合实时船舶操纵模拟试验进行综合分析,最终得出海港锚地与建筑物、构筑物和海底电缆管线等的安全距离建议值,为海港锚地设计提供依据。     

用于预报离岸管线膨胀的简化技术（英文）

In this study, we propose a method for estimating the amount of expansion that occurs in subsea pipelines, which could be applied in the design of robust structures that transport oil and gas from offshore wells. We begin with a literature review and general discussion of existing estimation methods and terminologies with respect to subsea pipelines. Due to the effects of high pressure and high temperature, the production of fluid from offshore wells is typically caused by physical deformation of subsea structures, e.g., expansion and contraction during the transportation process. In severe cases, vertical and lateral buckling occurs,which causes a significant negative impact on structural safety, and which is related to on-bottom stability, free-span, structural collapse, and many other factors. In addition, these factors may affect the production rate with respect to flow assurance, wax, and hydration, to name a few. In this study, we developed a simple and efficient method for generating a reliable pipe expansion design in the early stage, which can lead to savings in both cost and computation time. As such, in this paper, we propose an applicable diagram, which we call the standard dimensionless ratio(SDR) versus virtual anchor length(LA) diagram, that utilizes an efficient procedure for estimating subsea pipeline expansion based on applied reliable scenarios. With this user guideline,offshore pipeline structural designers can reliably determine the amount of subsea pipeline expansion and the obtained results will also be useful for the installation, design, and maintenance of the subsea pipeline.     

Simplified Technique for Predicting Offshore Pipeline Expansion

In this study, we propose a method for estimating the amount of expansion that occurs in subsea pipelines, which could be applied in the design of robust structures that transport oil and gas from offshore wells. We begin with a literature review and general discussion of existing estimation methods and terminologies with respect to subsea pipelines. Due to the effects of high pressure and high temperature, the production of fluid from offshore wells is typically caused by physical deformation of subsea structures, e.g., expansion and contraction during the transportation process. In severe cases, vertical and lateral buckling occurs, which causes a significant negative impact on structural safety, and which is related to on-bottom stability, free-span, structural collapse, and many other factors. In addition, these factors may affect the production rate with respect to flow assurance, wax, and hydration, to name a few. In this study, we developed a simple and efficient method for generating a reliable pipe expansion design in the early stage, which can lead to savings in both cost and computation time. As such, in this paper, we propose an applicable diagram, which we call the standard dimensionless ratio (SDR) versus virtual anchor length (L_A) diagram, that utilizes an efficient procedure for estimating subsea pipeline expansion based on applied reliable scenarios. With this user guideline, offshore pipeline structural designers can reliably determine the amount of subsea pipeline expansion and the obtained results will also be useful for the installation, design, and maintenance of the subsea pipeline.     

水下灌浆定形式海底管道立管固定装置研究

针对海底管道立管管卡发生损坏或者脱落,影响海底管道安全运行的情况,研制新型水下灌浆定型式海底管道立管固定装置。讨论水下管卡的结构形式,材料的选择及管卡灌浆的工艺流程。实验证明,该新型管卡能够代替原有管卡很好地对立管起到保护作用,能确保海底管道的安全运行。