海底悬空管道二次挖沟治理研究

发布时间：2019-03-16 11:08

【摘要】：海底管道将海上油气田的整个生产系统有机地联系起来,是目前最快捷、最安全和最经济可靠的海上运输方式,被誉为海上油气开发的生命线。然而,由于海底管道所处的海洋环境非常复杂,海底管道出现悬空现象是不可避免的,而悬空的致灾后果非常严重。因此,对海底管道悬空隐患的治理迫在眉睫。目前有关海底管道悬空治理的方法要么治理效果不佳,要么费用高昂,而二次挖沟治理能够弥补现有治理方法的不足,况且有关这方面的研究又极少。鉴于此,有必要对二次挖沟治理海底悬空管道进行研究。本文以运行状态下的海底水平悬空管道为研究对象,首先调研了国内外有关悬空管道力学分析与治理的文献,并对两端固支的海底自由悬空管道进行了静力计算和允许悬空长度的计算。然后,结合管土相互作用理论,运用AutoPIPE软件模拟海底悬空管道在挖沟治理过程中的位移变形和应力变化,通过强度分析来判断悬空管道的挖沟治理是否可行,得出如下结论:悬空段两边的海床支撑性质(刚性和弹性)不同,管道的位移变形和应力分布有所差异;海底悬空管道的挖沟治理过程中,内压的影响可忽略不计,而挖沟深度或管道温差的增加将明显增大管道应力;虽然一次挖沟成型和多次挖沟成型之后的管道应力相同,但多次挖沟成型能明显降低一次挖沟成型中的应力峰值,从而避免了悬空管道在挖沟过程中可能发生的屈服破坏。结合上述特征,拟合了相关公式,并制定了海底悬空管道挖沟治理的流程,该流程适用于风平浪静或波流影响很小下的挖沟施工,为海底悬空管道的治理提供了参考依据。
[Abstract]:Submarine pipeline, which links the whole production system of offshore oil and gas field organically, is the quickest, safest and most economical and reliable mode of maritime transportation at present, and is regarded as the lifeline of offshore oil and gas development. However, due to the complexity of the marine environment in which the submarine pipeline is located, it is inevitable that the submarine pipeline is suspended, and the consequences of the disaster caused by the suspension are very serious. Therefore, it is urgent to control the hidden danger of submarine pipeline suspension. At present, the methods of subsea pipeline suspension management are either poor or expensive, and the secondary trench treatment can make up for the shortcomings of the existing treatment methods, and the research on this aspect is very little. In view of this, it is necessary to study the treatment of submarine suspended pipeline by secondary excavation. In this paper, the horizontal suspended pipeline under the operating state is taken as the research object. Firstly, the literatures about the mechanical analysis and management of the suspended pipeline at home and abroad are investigated. The static and allowable suspended length of the free suspended submarine pipeline with fixed ends are calculated. Then, combined with the interaction theory of pipe and soil, the displacement deformation and stress change of submarine suspended pipeline in the course of trench treatment are simulated by AutoPIPE software, and the feasibility of trenching treatment of suspended pipeline is judged by strength analysis. The conclusions are as follows: the displacement deformation and stress distribution of the pipeline are different between the two sides of the suspended section due to the different properties of the seabed support (rigidity and elasticity); In the process of trench treatment of submarine suspended pipeline, the influence of internal pressure can be ignored, but the increase of trench depth or pipe temperature difference will obviously increase the pipeline stress; Although the pipe stress is the same after one-time trench forming and multiple trench-digging forming, the stress peak value in once-digging trench forming can be obviously reduced by multiple trenching forming, thus avoiding the possible yield failure of suspended pipe in trenching process. In combination with the above characteristics, the relevant formulas are fitted, and the process of trenching treatment for submarine suspended pipelines is formulated. This process is suitable for trenching construction under the condition of quiet wind and waves or little influence of wave currents, which provides a reference basis for the treatment of submarine suspended pipelines.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE973.8

【参考文献】