【作者】 田英辉；

【导师】 闫澍旺；

【作者基本信息】 天津大学 ， 岩土工程， 2007， 博士

【摘要】 海底管道作为海洋油气资源开发和运输的生命线,起着连接海上油气开采和陆上加工处理的枢纽作用。海底管道的投资往往在整个油气田项目中占有举足轻重的地位,如何合理地降低管道的造价并且保证其安全运行,是个长久以来具有挑战性的课题。我国海上原油大多含蜡量较高,具有较高的倾点和粘度,在管道输送时经常需要保温措施。传统使用的双重管道能够满足保温以及工程力学要求,但其缺点是钢材有近三分之二浪费在仅起保温和保护作用的外层钢管上。此外,焊接双重管道的速度慢,大大增加了施工船机设备的台班费用,而且维护修理难度较大。单重保温管道则省去外层钢管,代之以保温层和防护层,可以节约大量昂贵的钢材。此外,单重管道在铺设时只需焊接一层钢管,大大提高了施工速度。本论文以两个实际工程项目为依托,参考国外已有的实际经验和研究成果,进行了大量的试验研究和理论分析,并将所得到的试验结论和研究成果用于指导实际工程,旨在加快单重保温管道在我国的应用。在参考国内外已有的经验和成果的基础上,对保温材料进行了抗压和抗剪能力的物理性能试验,测定出其主要的力学指标。采用全比尺试件进行室内试验,测定出单重管层间的抗剪强度指标以及管道抗压性能指标。在铺管船上进行的现场全比尺试验是对单重管道铺设的模拟和演练,对试验过程中出现的现象进行了理论分析和数值计算,以达到改善设计和优化施工的目的。本文对管道铺设进行了理论分析,参考已有的成果得出奇异摄动解,并采用牛顿割线迭代法将其实现为计算程序代码,计算出管道在铺设时的变形和内力。对单重保温管道在施工以及运行期间的层间剪切力进行了校核,提出了一套简化的计算模型和计算方法,并将此成果成功用于指导工程实践。采用有限元软件,对管道在进行铺设时受张紧器的压夹作用进行了仿真模拟,计算出其安全储备情况。从弹性理论出发对管道在静水压力作用下进行了压溃分析,并采用有限元软件对管道进行了线性和非线性屈曲分析。管道膨胀弯的吊装方案采用有限元软件对三种方案进行比较而达到优化的目的。对管土相互作用这一专项进行了研究,并将UWAPIPE模型进行了改进,并将其作为宏单元分别采用显式和隐式算法整合到结构计算程序中。利用该程序,计算了管道在海底荷载下的响应,并研究了悬跨段长度对管道的变形产生的影响。鉴于单重保温管道所具有的优势,可以预计其具有广泛应用的前景和潜力。然而,单重保温管道在我国尚处于起步阶段,到目前总计已施工运行的管道也不过两三条。施工操作经验还有待于进一步积累,研究水平和深度也有待于深入。本论文是我国开始使用海底单重保温管道而进行的试验研究和理论分析一个初步总结,作者希望抛砖引玉,能为将来的研究和应用提供一些参考。更多还原

【Abstract】 Subsea pipelines are the crucial link between oil and gas development and mainland as the lifelines of transportation and gathering of petroleum crude. The investment to pipeline accounts for the big part of the whole cost of oil field. It has been being a challenging subject to reduce the expenditure and maintain the good conditon of pipeline.Heat preservation measures are inevitably required in China offshore projects because most of the crude oil has high pour point and viscocity. The conventional pipe-in-pipe structure consumes steel material too extravagantly because near 2/3 steel is used by the outer pipe, which only acts as the protect coat and heat preservation, although it may be capable of the task. Moreover, this tradional pipe increases the the cost on construction because the welding work is quite time consuming and maintain cost is very high. Considerable amount of steel can be saved using thermally insulated pipeline, where the outer steel pipe is substituted by heat insulated layer and jacket. It is self-evident that faster laying speed is anticipated because only single layer steel pipe is needed to weld. Referring to the foreign experiences and research results, a lot of experiments and threotical study have been carried out. Based on two practical engineering projects, this paper aims to accelerate the development and application of this new type pipeline in China by directing the engineering projects.Laboratory tests have been lauched to investigate the compress and shear strength of heat preserving material. Full scale specimens were adopted to measure the shear strength between layers and compress strength of the pipe. Furthermore, the experiments carried on the laying barge were the preview and simulation of pipe laying. Some phonomena occurred during the tests have been explained from the view of therotical analysis and numerical calculation.Referring to available research results, pipe laying analysis has been performed and solution has been obtained using a singular disturbation method. The results were implemented into program code within a Newton-secant iteration framework. The configuration and stress of the pipeline can be achieved with this program. A serial of calculation models were introduced and simple equations has been acquired to check the shear stress between layers of pipeline during both laying and operation period. Simulation of pipeline in tensioner was carried out with FEM software to check the safety factor. Both linear and nonlinear buckle analysises have been performed to calculate the safety status under hydrostatic pressure. The hoist of elbow has been optimized by comparing three schemes with FEM analysis. The research progress of pipe soil interaction has been retropested.The UWPAPIPE models were improved and implemented into a structure analysis program as macroelemet. The pipeline response was examined due to hydrodynamic load with the program to study the influence of the span length. Prospective widely application of thermally insulated pipeline is anticipated since it has the unique advantages. However, thermally insulated pipeline is still immature with total 2-3 finished pipelines in China. Therotic study practical construction experience is anticipated to intensify. This thesis could be taken as a summary of experiment analysis and theoretical stuy of the beginning application of thermally insulated pipeline in China. The author humbly hopes all these could provide some references to prospective researchers.更多还原