【作者】 李长东；

【导师】 桑松；

【作者基本信息】 中国海洋大学 ， 港口、海岸及近海工程， 2014， 硕士

【摘要】 随着海上油气资源的开采逐渐向深水区转移，浮式海洋平台的应用越来越广泛。半潜式平台抗风浪能力强，适用水深范围广，钻机能力强，因此半潜式钻井平台成为深水钻井的主流平台。开展半潜式平台的相关研究对于我国开发南海深水区的油气资源具有十分重要的意义。本文以我国南海某半潜式钻井平台为研究目标，对平台在南海作业海况及生存海况下的运动情况进行了研究。在此基础上本文探索了一些控制平台运动响应的方法，总结了一系列规律。论文的主要研究内容如下：首先，介绍了工程上广泛应用的四种浮式平台（半潜式平台、单柱式平台、张力腿平台以及浮式生产储油轮）的发展及应用。同时，对半潜式平台的研究热点及现状进行了综述。其次，基于水动力计算软件AQWA-Line，建立了目标平台的水动力计算模型，采用三维势流理论，对平台模型进行了频域分析，获得了平台的附加质量系数、辐射阻尼系数和运动幅值响应算子（RAO）等水动力参数，分析了平台在规则波中的运动特性。在频域分析的基础上，建立了目标平台的时域耦合计算模型，利用AQWA-Drift模块，模拟了目标平台在实际海洋环境中的运动，模拟的海况条件有作业海况和生存海况，分别计算了风浪流0°和90°两种典型入射方向，得到了平台各个自由度的运动响应时程及响应谱，以及系泊缆的受力情况。最后，以目标平台为原型，探索了重心高度、吃水深度以及垂荡板结构对平台运动的影响规律，详细讨论了垂荡板的质量、安装水深、面积以及形状对平台运动性能的改变，通过对比各种平台在频域和时域中的运动表现，总结了一些关于半潜式平台响应控制的规律。本文研究了半潜式平台在规则波和不规则波中的运动响应，分析了平台各自由度的运动特性，探讨了抑制平台运动响应的一些方法，得出的结论对于准确预报半潜式平台的水动力性能和平台的优化设计具有重要的参考价值。更多还原

【Abstract】 With the exploitation of offshore oil and gas resources gradually shifting to thedeepwater areas, floating offshore platform is used more and more widely.Semi-submersible drilling platform has become the main platform for deepwaterdrilling because of its special characteristics: the great performance of stability, thewide water depth range of operating and the strong ability of drilling. Thus, it will beof great significance to carry out comprehensive research on Semi-submersibleplatform.In this paper, the motion performance of a semi-submersible drilling platformwhich is serving the South China Sea in operating and survival conditions is studied.On this basis, some methods of controlling the platform motion response are explored,leading to some conclusions. The main work of this paper can be concluded asfollows:Firstly, the main types of the compliant platform used for ocean oil and gasexploitation, such as TLP, Spar, FPSO and semi-submersible platform, have beenintroduced, their developmental process and engineering application have beendemonstrated. Meanwhile, the studies on the semi-submersible platform have beenreviewed.Secondly, a hydrodynamic numerical model of the target platform is built basedon the AQWA-Line software to analyze the hydrodynamic parameters, such as addedmass coefficients, radiation damping coefficients and the RAOs, in the frequencydomain of the semisubmersible platform using the three-dimensional potential theory.On the basis of frequency domain analysis, coupled analysis in time domain of thesemisubmersible and its mooring system are carried out with the AQWA-Driftsoftware in both operating and survival sea conditions considering different typical wave directions, to obtain motion responses in6degree of freedom and tension ofmooring system.Lastly, the effects of different gravity center heights, drafts and heave plates onthe hydrodynamic performances of whole system are explored respectively bycomparison with the original platform. Particularly, changes of the mass, depth, areaand shape of heave plate on motion performance are discussed in detail. Conclusionsare obtained about motion control of semisubmersible platform by comparison of themotion performance of different platforms in both frequency and time domainanalysis.In this paper, the motion response of semi-submersible in regular and irregularwaves is studied. Some methods to improve the platform motion are discussed as well.Conclusions obtained in this paper will be useful in prediction of hydrodynamicperformance accurately and further design of the semi-submersible.更多还原