老龄平台加固延寿中的极端环境要素设计标准研究

The oil platforms in operation in the Bohai Sea have gradually come into later service period. However, these platforms are playing important roles in the oil and gas production at present. The reinforcement and life extension of aged platforms can make the production cost much lower. The double threat of summer typhoon and winter cold wind constraints the sustainable development of oil and gas production in the Bohai Sea. Based on the historical data, this project will take different characters of the above 2 kinds of storm processes in consideration, and set up a synchronous numerical model to reappear the storms including various environmental elements, such as wind, waves, current and storm surge elevation. The multi-dimensional statistical samples of concomitant extreme wind speed, wave heights, current speed and storm surge elevation can be obtained. Theoretical multivariate entropy distributions will be proposed based on maximum entropy principle. Furthermore, compound distributions will be constructed to predict joint return values of environment elements by considering the impact of the occurrence of severe whether processes. The relationship between the structural responses of the platform and extreme environmental loads can be established through model tests and numerical simulations. This study will present the limit state equation about the internal rate of life extension investment of aged platforms, then analyze the investment risk, finally propose the joint design standards of marine environmental elements about life extension which suitable to the aged platforms in the Bohai Sea, meanwhile give the recommended procedures for engineering practice. The ability of resolving the contradiction between economic and security of the operation of platforms has important theoretical and engineering significance for the guidance of continuous production, maintenance, decommissioning and other problems of aged platforms, which will avoid the serious accidents, such as the platform collapse.

我国在渤海建造的石油平台陆续进入后服役期，而这些平台在现阶段原油生产中仍发挥着重要作用。通过对老龄平台的加固延寿，将使生产成本大大下降。台风与寒潮的双重威胁制约着渤海油气资源开采的可持续发展，本项目将考虑其不同特点，收集历史资料，根据风场的差异构建不同的数值后报模型，重现风、浪、流及风暴潮增减水过程，对多种环境要素进行同步抽样。基于联合最大熵原则，推导多维最大熵分布。考虑灾害性天气过程发生频次的影响，进一步构建复合型分布，预测环境要素的联合重现值。通过模型试验与数值计算，获得平台结构响应与极端环境荷载的关系。以老龄平台延寿投资的内部收益率建立极限状态方程，进行投资风险分析，提出适用于渤海海域老龄平台加固延寿的海洋环境要素的联合设计标准，给出推荐做法。解决平台运行的经济性和安全性之间的矛盾，对老龄平台的继续使用、维修、退役等问题进行指导，避免出现平台倒塌的恶性事故，具有重要的理论与工程意义。

我国在渤海石油平台陆续进入后服役期，由于平台所在地的油气资源仍未开采完毕，通过对老龄平台的加固延寿，将使油气开采成本大幅下降。本项目考虑了渤海区域台风与寒潮的不同特点，收集历史资料，构建数值后报模型，重现风、浪、流及风暴潮增减水过程，对多种环境要素进行同步抽样。提出了复合型多维最大熵分布模型，预测多种环境要素的联合重现值。通过模型试验，获得平台结构响应与极端环境荷载的关系。以老龄平台延寿投资的内部收益率建立极限状态方程，进行投资风险分析，提出适用于渤海海域老龄平台加固延寿的海洋环境要素联合设计标准。解决平台运行的经济性和安全性之间的矛盾，对老龄平台的继续使用、维修、退役等问题进行指导程意义。