钢悬链线式立管论文深水钢悬链式立管S型铺设方法分析研究

1、钢悬链线式立管论文：深水钢悬链式立管S型铺设方法分析研究【中文摘要】深水钢悬链式立管的铺设方法主要有两种:J型铺设和S型铺设。其中S型铺设由于其能够较为有效的保证焊缝质量且铺管速度较快而受到青睐,逐渐的由浅水海域向深海发展。本文利用广泛应用于海洋管线的强度、疲劳以及相关的安装铺设等方面计算的有限元软件OrcaFlex进行深水钢悬链式立管的S型铺设分析。主要的研究内容及成果概括如下:(1)介绍了钢悬链式立管的主要铺设方法,总结了近几年国内外深水立管铺设的主要工程实例中所采用的铺设方法以及铺设水深等。(2)在不同条件下对立管的S型铺设状态进行分析计算,讨论对比了托管架参数、铺设水深以及立管内部介质

2、不同时立管受力状态所表现出来的差异,特别是荷载较为复杂的上弓段。立管上弓段是立管与托管架之间的多点连续支撑,局部的应力/应变将会发生突变,本文通过计算分析详细讨论了立管与托辊相互作用的特点以及控制方法。(3)本文详细讨论了立管内部介质所带来的影响。根据DNV以及API相关规范从理论上分析了内部介质影响的实质,并通过软件分析了立管内部介质分别为空气和海水时立管受力状态以及所需张紧力的不同。综合二者的优劣性,本文提出了部分充水的铺设方法并进行了分析。(4)经过分析,本文得到的主要结论有:a、水深越大,则托辊的反作用力即立管与托管架的相互作用力越大;b、当立管入水角较小时,应尽量控制张紧力,使得立管

3、与托管架的分离点高于托管架末端,以避免发生应变/应力上的较大突变;c、在进行安装铺设分析时,若托管架已不适用需要调整时,应该优先考虑增大托管架的长度而非减小入水角;d、立管与托辊的相互作用一般在第一个托辊以及分离点附近的托辊处作用力最大,而在中间区段的荷载相对较小;e、采用部分充水的方法对立管进行铺设安装,不仅能够有效的降低立管壁厚的要求,节约成本,还能在一定程度上降低对设备的要求,同时,也使得托管架具有更广泛的适用性(更大的适用水深等)。本文的创新点在于:(i)、利用弹簧模拟托管架与立管的相互作用,立管表现出多点支撑的受力特点,与实际状况相符;(ii)比较了立管内部介质分别为空气和海水时在规

4、范理论以及实际的受力特点上所表现出来的差异;(iii)总结内部介质分别为空气和海水时二者的优缺点,提出了部分充水的铺设方法,并进行了相关的计算分析。【英文摘要】At the present, J-lay and S-lay are main methods used in the installation of steel catenary risers(SCR) in deepwater. The S-lay method is developed rapidly from shallow water to deep water for its high weld quality and l

5、ay speed. So the S-lay analysis of SCR is done in this paper by Orcaflex software which is applied wildly to analyse the strength、fatigue and installation of pipelines. The main contents and issure of this paper are as follow:(1) The main installation methods of SCR are introduced and the informatio

6、n,such as installation method、water depth ect, of real installation experience is concluded(2) The S-lay method is analysed with different conditions and the characteristics of risers in different stiger parameter、water depths and riser contents are discussed;(3) The influence coming with different

7、riser contents are discussed in detail. In order to make the advantage of two installation states (flooded installed and empty installed) to the greatest degree, the partial flooded installed method is developped and analysed in this paper.(4) The conclusion summarized from the parper are as follow:

8、(a) the reaction force between the riser and stinger is increasing with deeper water;(b) in order to avoid the stress/strain jump at the end section of stinger, the tension must be controlled to make the lift-off point of riser away from the stinger end point when the horizonal launch angle of sting

9、er is small;(c) when the stinger is not suitable to use, the stinger length will be adjusted first rather than the launch angle which is larger enough;(d) the first roller reaction and the lift-off point roller reaction are more serious than the others, generally; (e) thinner riser thickness can be

10、chosen that will cut the cost in a certain degree, and the stinger will be used more wildly(deeper water ect.) when the partial installed method is adopted.The innovations presented in this paper are: (i) the interaction between rollers of stinger and riser are modelled by linkers which can simulate the loading on risers well and be in agreement with the fact. (ii) the differences coming with the varying riser inner contents are shown. (iii) the partial flooded installed method is developped and analysed in this paper to avoid the disadvan