悬挂状态下钻井隔水管的结构动力学及涡激振动研究

发布时间：2018-07-11 13:49

本文选题：钻井隔水管 + 硬悬挂　；参考：《上海交通大学》2015年硕士论文

【摘要】：钻井隔水管是连接钻井平台与井口的重要且最易发生疲劳破坏的管柱结构,跨越整个水体区域,在深水中受到波浪与海流的作用,极易引发结构动态响应及涡激振动,导致强度破坏或疲劳破坏。而在遭遇台风时,基于安全性考虑要求钻井平台悬挂隔水管提前撤离,隔水管在洋流和平台航行速度的共同影响下存在安全隐患。本文采用有限元软件对硬悬挂隔水管系统的动力学问题进行模拟,研究悬挂长度、航速、航向对动力学响应的影响,对避台风撤离时的硬悬挂隔水管进行可行性分析。研究表明:随着航速增加,隔水管在运动时所受到的动载荷增大,需要减小隔水管的悬挂长度;随着航向角增大,平台由顺流航行变成逆流航行,隔水管受到的环境载荷增大,安全性降低。采用软件Shear7对硬悬挂隔水管避台风航行时涡激振动进行数值计算,分析了实际尺寸隔水管系统在避台风撤离时在不同航行条件及不同悬挂长度下的涡激振动响应。隔水管并非越短越好,要综合考虑洋流剖面、隔水管配置和平台航行的影响;在不同悬挂长度及航行条件下的VIV响应,在撤离作业前应尽量避免在高流速区布置浮力单根。采用FLUENT结合UDF,在深水或超深水环境中,针对钻井隔水管的涡激振动响应,在二维空间中模拟1DOF和2DOF的流固耦合问题。分析了1DOF和2DOF下的涡激振动特性,得到了实际尺寸隔水管的升力系数、阻力系数和频率特征。隔水管涡激振动的振幅、振动频率、升阻力系数与约化速度有较大关系。在锁定区范围内,隔水管涡激振动振幅、升力系数、阻力系数均较大,最大升阻力系数幅值可达到3.0-4.0,这远大于规范中选取的升力系数和阻力系数。
[Abstract]:Drilling riser is an important string structure which connects drilling platform and wellhead and is most vulnerable to fatigue damage. It crosses the whole water area and is subjected to waves and currents in deep water, which can easily cause dynamic response and vortex-induced vibration of the structure. Cause strength damage or fatigue failure. In the event of typhoon, due to safety considerations, the drilling platform hoisting riser is required to withdraw ahead of time, and the riser has hidden dangers under the influence of ocean current and platform navigation speed. In this paper, the finite element software is used to simulate the dynamic problems of the hard suspension riser system. The effects of suspension length, speed and course on the dynamic response are studied, and the feasibility analysis of the hard suspension riser during the evacuation of typhoon is carried out. The results show that with the increase of the speed, the dynamic load of the riser increases and the suspension length of the riser needs to be reduced. With the increase of the heading angle, the platform changes from downstream navigation to counter-current navigation, and the environmental load on the riser increases. Safety is reduced. By using software Shear7, the vortex-induced vibration of a hard-suspended riser during typhoon avoidance was calculated. The vortex-induced vibration response of the riser system under different sailing conditions and different suspension lengths during typhoon avoidance was analyzed. The shorter the riser the better, the influence of ocean current profile, riser configuration and platform navigation should be taken into account, and the VIV response under different suspension length and navigation conditions should be avoided in the high velocity zone before evacuation. The fluid-structure coupling problem of 1DOF and 2DOF is simulated in two-dimensional space by using fluent and UDF in deep water or ultra-deep water environment, aiming at the vortex-induced vibration response of drilling riser. The vortex-induced vibration characteristics of 1 DOF and 2 DOF are analyzed, and the lift coefficient, resistance coefficient and frequency characteristics of the actual size riser are obtained. The amplitude, vibration frequency and drag coefficient of vortex induced vibration of riser are related to the reduction velocity. In the locking region, the amplitude of vortex-induced vibration, lift coefficient and resistance coefficient of riser are larger, and the amplitude of maximum lift resistance coefficient can reach 3.0-4.0, which is much larger than the lift coefficient and drag coefficient selected in the specification.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE951

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