深水隔水管法兰系统的安全性能研究

发布时间：2018-08-13 17:33

【摘要】：深水钻井隔水管法兰作为水下管道连接中的一种重要装备将直接影响海上钻井船或平台的稳定性和安全性,而法兰连接要保证管道、立管和其设备安全正常的运行,必须保证整体结构的强度,连接处良好的密封性,以及能够迅速并多次重复装拆,但由于钻井环境条件随水深的增加变得更加复杂,隔水管法兰受力状态更加恶劣和复杂,其连接装置的强度、稳定性能否适应深水钻井的问题,在国内也未进行过系统的研究。因此,研究深水隔水管法兰系统的安全性能,对于减少钻井平台上的安全生产事故,降低海洋钻井工作带来的巨大损失具有十分重要的意义。对隔水管法兰系统安全性能的研究主要从其力学性能入手,以深水隔水管法兰连接接头为研究对象,通过预加载连接试验、轴对称拉伸试验、水压试验,三个试验研究隔水管接头在不同预加载荷条件下的应力水平及水压试验压力条件下的密封与变形性能。因此,本文展开了一系列有限元模拟分析、试验实测及综合对比分析研究工作。首先,通过对法兰试验载荷作用位置的分析,综合考虑法兰的应力水平以及焊接工艺,结合额定载荷拉伸试验和水压试验的要求,根据API Spec 16R隔水管接头试验的要求,设计能同时满足三个试验要求的两种试验装置,采用有限元模拟对试验装置Ⅰ和装置Ⅱ的强度和稳定性分别进行校核。从装置的应力分布、制造工艺、制造成本等三个方面综合对比两种试验装置,得出两种试验装置中能够完成法兰试验工作的相对合适的试验装置结构。其次,使用Solidworks建立隔水管法兰连接接头的三维模型,通过对法兰和螺栓的应力计算,采用ANSYS Workbench有限元模拟分析法兰在预加载荷试验、额定载荷拉伸试验和水压试验条件下的应力分布规律,并选择应力强度校核的截面位置,针对法兰应力较集中区域和法兰壁厚变化区域选择评定路径,将不同路径的法兰线性化应力结果和相应许用应力进行比较校核。最后,通过预加载荷连接试验、额定载荷拉伸试验及水压试验三部分现场试验测试,分析隔水管接头在不同预加载荷条件下特定部位的应力水平以及在水压试验压力条件下的密封与变形性能。根据试验实测结果与有限元模拟结果的对比分析,结合试验实测情况,综合考虑试验与模拟中存在误差的原因,得出模拟与试验中存在相对差值偏大点的主要误差来源。证明试验所得数据分析结果与数值模拟分析结果具有良好的一致性,有限元模拟在隔水管法兰试验装置下的计算过程可代替法兰试验,对其安全性能的研究具有实质性意义,能够为我国在深水隔水管法兰系统的安全可靠性提供验证性保证。
[Abstract]:As an important equipment in underwater pipeline connection, deep water drilling riser flange will directly affect the stability and safety of offshore drilling vessel or platform, and the flange connection should ensure the safe and normal operation of pipeline, riser and its equipment. It is necessary to ensure the strength of the whole structure, the good sealing of the joints, and the ability to install and disassemble quickly and repeatedly, but as the drilling environment conditions become more complex with the increase of water depth, the stress state of the riser flange is more severe and complex. Whether the strength and stability of the connection equipment can adapt to the problem of deep water drilling has not been systematically studied in China. Therefore, it is of great significance to study the safety performance of deep water riser flange system for reducing the safety accidents on drilling platform and reducing the huge loss caused by offshore drilling work. The research on safety performance of riser flange system is mainly based on its mechanical properties. The connection joint of deep water riser flange is taken as the research object, through preloading connection test, axisymmetric tensile test, water pressure test, Three tests were carried out to study the sealing and deformation properties of water-insulated pipe joints under different preloading conditions and under hydraulic pressure conditions. Therefore, a series of finite element simulation analysis, experimental measurement and comprehensive comparative analysis are carried out in this paper. First of all, by analyzing the load position of flange test, considering the stress level of flange and welding technology, combining the requirements of rated load tensile test and hydraulic test, according to the requirements of API Spec 16R water-proof pipe joint test, Two kinds of test devices which can meet three test requirements simultaneously were designed. The strength and stability of test apparatus I and II were checked by finite element simulation. In this paper, the stress distribution, manufacturing process and manufacturing cost of the two test devices are comprehensively compared, and a relatively suitable structure of the test device which can complete the flange test work is obtained. Secondly, the three-dimensional model of flange joint of riser is established by using Solidworks. Through the stress calculation of flange and bolt, ANSYS Workbench finite element simulation is used to analyze the pre-loading test of flange. Under the condition of rated load tensile test and hydraulic pressure test, the stress distribution law and the section position of stress intensity check are selected, and the evaluation path is chosen for the flange stress concentration area and flange wall thickness change area. The results of linearization stress of flange with different paths and the corresponding allowable stress are compared and checked. Finally, through the connection test of pre-loading, the tensile test of rated load and the test of hydraulic pressure, the field test is carried out. The stress levels of the pipe joints under different preloading conditions and the sealing and deformation properties of the joints under the pressure of hydraulic test are analyzed. According to the comparison and analysis between the experimental results and the finite element simulation results, combined with the experimental results, and considering the reasons for the errors in the experiment and the simulation, the main error sources of the relative difference between the simulation and the test are obtained. It is proved that the experimental data analysis results are in good agreement with the numerical simulation results. The calculation process of finite element simulation under the flange test device of riser can replace the flange test, and the study of its safety performance is of substantial significance. It can guarantee the safety and reliability of deep water riser flange system in our country.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE92

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