半潜式平台水动力性能分析与优化设计

发布时间：2018-10-17 07:30

【摘要】：随着工业化的发展,人类对油气资源的需求不断增长,陆上和近海石油资源的减少,促使人类更加关注深海资源的勘探和开采。由于水深增加,传统的重力式平台和导管架平台由于自身造价大幅度提高而不再适用,因此适合于深海作业的海洋平台成为研究的热点。目前,适用于深海钻采的平台类型主要有立柱式平台(Spar)、张力腿平台(TLP)和半潜式平台(SEMI)。半潜式平台由于具有更大的甲板空间和可变载荷、更大的作业水深范围、更强的钻采能力和总投资相对较小等优点,将是满足我国对南海油气资源开采要求的最佳平台类型。本文围绕半潜式平台,开展水动力性能分析与多目标优化设计。半潜式平台水动力性能分析。以三维势流理论为基础,在我国南海十年一遇的海况下,通过水动力学软件AQWA对一座水深为1500m的深水半潜式平台进行了运动性能分析。首先,建立了半潜式平台的水动力模型,计算得到平台的附加质量、附加阻尼和RAO等水动力参数,然后在我国南海十年一遇的海况下,分别在频域和时域对平台的运动性能进行了数值模拟,最后对二者结果进行了对比,发现在频域计算和在时域计算得到的平台的纵荡和横荡的计算结果相差较大,垂荡、横摇和纵摇的计算结果较为吻合,经分析发现两种计算方法得出不一样的结果主要是由于波浪低频力的影响。半潜式平台水动力性能与造价的多目标优化设计。为了降低半潜式平台的垂荡响应和建造成本,根据已有的半潜式平台的数据确定了平台主尺度的变化范围,通过最优拉丁超立方抽样方法选取了20组样本点,采用径向基代理模型对平台的垂荡、横摇、气隙和稳性进行了函数拟合。通过优化软件Isight,以平台的垂荡响应和建造成本为目标,气隙、横摇、稳性等为约束条件,对平台的主尺度进行优化,得到了优化问题的Pareto解集。本文对半潜式平台的水动力性能及其优化设计方法的研究结果,对半潜式平台的概念设计阶段具有参考意义。
[Abstract]:With the development of industrialization, the increasing demand for oil and gas resources, and the decrease of onshore and offshore oil resources, urge people to pay more attention to the exploration and exploitation of deep-sea resources. Because of the increase of water depth, the traditional gravity platform and jacket platform are no longer suitable for the deep sea operation due to their high cost, so the offshore platform suitable for deep-sea operation has become a hot research topic. At present, the main types of platforms suitable for deep-sea drilling and production are column type platform (Spar), tension leg platform (TLP) and semi-submersible platform (SEMI). The semi-submersible platform has the advantages of larger deck space, variable load, larger water depth range, stronger drilling and production capacity and lower total investment, etc. It will be the best platform type to meet the requirements of oil and gas exploitation in the South China Sea. In this paper, hydrodynamic performance analysis and multi-objective optimization design are carried out around semi-submersible platform. Hydrodynamic performance analysis of semi-submersible platform. Based on the theory of three-dimensional potential flow, the motion performance of a deep-water semi-submersible platform with a depth of 1500m was analyzed by using the hydrodynamic software AQWA under the once-in-a-decade sea conditions in the South China Sea. Firstly, the hydrodynamic model of semi-submersible platform is established, and the additional mass, damping and RAO parameters of the platform are calculated. The motion performance of the platform is numerically simulated in frequency domain and time domain respectively. Finally, the results are compared. It is found that the calculated results of longitudinal and transverse motion of platform in frequency domain and in time domain are quite different. The results of rolling and pitching are in good agreement with each other. It is found that the difference between the two methods is mainly due to the influence of low-frequency wave forces. Multi-objective optimization design of hydrodynamic performance and cost of semi-submersible platform. In order to reduce the heave response and construction cost of the semi-submersible platform, the variation range of the main scale of the platform is determined according to the data of the existing semi-submersible platform, and 20 groups of sample points are selected by the optimal Latin hypercube sampling method. The radial basis function agent model is used to fit the heave, roll, air gap and stability of the platform. Based on the optimization software Isight, the main scale of the platform is optimized under the constraints of air gap, roll and stability, and the Pareto solution set of the optimization problem is obtained by taking the heave response and the construction cost of the platform as the target and the air gap, roll and stability as the constraint conditions. The results of the research on the hydrodynamic performance of semi-submersible platform and its optimal design method are useful for the conceptual design of semi-submersible platform.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P742

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