北极巴伦支海浮式平台结构设计的环境条件研究

The Artic sea ice is a major security threatening to the floating platforms in the Barents Sea. From the view of dynamics and thermodynamics, the physical mechanism and theoretical basis of polar sea ice are studied. Considering the interaction of sea ice and current, a coupled sea-ice model is constructed. Meanwhile the research is conducted for numerical hindcasting of wind, waves and current occurred in the target sea area. Thus the recurring data of long-term disastrous weather processes can be obtained. In the Barents Sea, the spatial intensity of cold wave can be described by the space marked point process model of cold wave, while the process of intensity can be dynamically described by the time marked point process model. Based on stochastic process theory, the risk analysis of structural strength of floating platforms is proposed, so that the joint design standard of a variety of environmental elements can be obtained. The marine structure design parameters of each block of the Barents Sea will systematically be given, including the conditions of operation, design and fatigue, which can offer Chinese engineering corporations environmental security guarantee condition and technical support for participation of ocean oil and gas exploitation in the Arctic area.

海冰是北极巴伦支海浮式平台主要的安全威胁。从动力学和热力学角度对极地海区海冰的物理机制和理论基础进行研究。考虑海冰与海流的相互作用，建立海冰-海洋耦合模式。同时进行风，海浪以及海流的数值后报研究，从而获得所研海域长期灾害性天气过程的再现数据。在巴伦支海域，寒潮的空间标值点过程模型可以描述寒潮的空间强度，而寒潮的时间标值点过程模型可以动态地描述固定点寒潮的过程强度。基于随机过程理论，开展浮式平台结构强度的风险分析。提出浮式平台结构响应的神经网络算法。获得浮式平台在巴伦支海域的多种环境要素的联合设计标准。系统给出巴伦支海域各个区块的海洋结构设计参数，包括作业条件、设计条件以及疲劳条件。为我国工程公司参与开发北极油气资源开发提供环境安全保障条件，作好技术储备。

海冰是北极巴伦支海浮式平台主要的安全威胁。本项目考虑海冰与海流的相互作用，建立海冰-海洋耦合模式。开展了风，海浪以及海流的数值后报，获得海洋环境要素的长期时程序列。针对巴伦支海域出现的极地低压天气过程，构建了多维要素的联合随机模型。提出了一种利用神经网络算法预测系泊张力和结合贝叶斯网络评估系泊线失效概率的方法。基于IFORM拓展了环境等值法，能够考虑短期极端响应的不确定性。为评估系泊系统荷载的设计重现值，提出了简化的离散方法来进行长期极端响应分析，避免了复杂积分求解所需的巨大计算代价。采用四种荷载评估模型(称为1D EC、2D EC、3D EC拓展模型和长期极端响应模型)进行了比较。与环境等值线法相比，长期极端张力响应模型得到了最大的设计载荷。该结果表明考虑所有短期环境条件对预测浮式结构的长期设计荷载具有重要意义。以上创新成果为北极油气开发提供了获取环境设计参数的一套系统方法，以巴伦支海为例，给出了浮式平台设计的环境要素重现值，为安全高效开发油气资源提供了基础数据保障。