内外流因素对海底悬跨管道振动特性的影响分析

发布时间：2018-05-30 06:40

本文选题：悬跨管道 + 内外流因素　；参考：《东北石油大学》2017年硕士论文

【摘要】：海底管道是海洋油气生产系统的重要组成部分,被喻为海上油田的生命线。然而由于海洋环境的复杂性与特殊性,海底管道不可避免的会形成悬跨段,悬跨段的出现是管道发生疲劳失效的主要原因。因此,针对海底悬跨管道的振动特性进行研究对其安全运行具有重要意义。本文以海底悬跨管道为研究对象,分析了悬跨管道的形成原因和悬跨类型,将管道以微元形式对管内流体以及管壁进行受力分析,系统分析了海洋环境载荷条件下波浪对管道产生的作用力,研究了描述流动特征、结构特征以及流固耦合特征的无量纲参数。针对渤海埕岛油田悬跨管道,运用ANSYS有限元软件建立悬跨管道模型和流体域模型,对悬跨管道在不同内外流因素的影响下的振动特性进行研究。研究结果表明,悬跨管道的前六阶自振频率和应力随着管内流速的增加而减小,且相邻两阶频率相同而方向不同。悬跨管道的自振频率随着海流速度的增加随之缓慢增加。进一步探索内流因素对悬跨管道的影响,应用有限元软件对海底悬跨管道在不同内流速度和不同管内压强条件下的中节点竖向变形和应力分布进行模拟分析,得到相应的关系曲线图。根据目标海域埕岛油田海底悬跨管道的现状,总结了挠性软管跨接法、水下短桩支撑法等可靠的防治措施,为悬跨管道的安全运行和维护提供参考依据。
[Abstract]:Submarine pipeline is an important part of offshore oil and gas production system, and is regarded as the lifeline of offshore oil field. However, because of the complexity and particularity of marine environment, the submarine pipeline will inevitably form a suspended span section, which is the main reason of pipeline fatigue failure. Therefore, it is of great significance to study the vibration characteristics of submarine cantilever pipeline for its safe operation. In this paper, the formation reason and type of suspended span pipeline are analyzed, and the fluid and wall of the pipe are analyzed in the form of micro-element. The forces produced by waves on pipelines under marine environmental loads are systematically analyzed, and the dimensionless parameters describing the characteristics of flow, structure and fluid-structure coupling are studied. In view of the overhanging pipeline in Chengdao Oilfield in Bohai Sea, the model of overhanging pipeline and fluid domain model were established by using ANSYS finite element software, and the vibration characteristics of suspended span pipeline under the influence of different internal and external flow factors were studied. The results show that the first six order natural frequencies and stresses decrease with the increase of flow velocity, and the two adjacent frequencies are the same and the directions are different. The natural vibration frequency of the overhanging pipeline increases slowly with the increase of the current velocity. In this paper, the influence of internal flow factors on suspended span pipeline is further explored. The vertical deformation and stress distribution of mid-node of submarine suspended span pipeline under different internal flow velocity and pressure are simulated and analyzed by using finite element software. The corresponding relation graph is obtained. According to the present situation of overhanging pipeline in Chengdao Oilfield in the target area, this paper summarizes the reliable prevention measures such as flexible hose straddle method, underwater short pile support method and so on, which provides a reference for the safe operation and maintenance of the suspended span pipeline.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE973.92

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