【作者】 杨冬平；

【导师】 陈国明；

【作者基本信息】 中国石油大学 ， 安全技术及工程， 2010， 博士

【摘要】 海洋平台安全数字化技术不仅仅是一个新的概念,尽管它所涉及的理论基础、技术数据及工程应用都是建立在现有的知识基础之上,但它是从更高的层次、从系统论和一体化的角度来发展和整合现有知识,从而为更全面、更深入、更有效地挖掘和利用现有平台的各种数据,进行结构安全仿真分析,保证平台安全运行,为提高我国海洋平台全寿命安全管理水平起到积极促进作用。本文以国家863计划专项课题“近海老龄平台延寿技术研究”、国家自然科学基金项目“面向老龄平台延寿工程的寿命预测与管理理论及方法研究”和山东省自然科学基金“近海结构虚拟安全理论及其应用研究”为依托,以海洋固定导管架平台为研究对象,提出构建海洋工程结构数字安全技术体系的新设想,系统开展导管架平台数字安全仿真及应用研究,在海洋平台环境数字荷载建模、海洋平台数字结构建模、海洋平台冰疲劳荷载建模、复杂管节点建模方法、平台碰撞风险评估、平台连续倒塌动力非线性分析、老龄平台延寿决策模型、海洋平台数字安全仿真环境、海洋平台安全评估技术体系、海洋结构数字安全仿真软件开发等方面的研究取得了较大进展,可为我国海洋油气资源钻采装备安全提供有效的技术支持。主要研究成果归纳如下:1、海洋导管架平台数字荷载模型研究研究海洋平台数字荷载模型建模步骤,设计海洋平台数字荷载模型系统框架,并开发相应的6个数字荷载计算模块,即海风荷载模块、波浪荷载模块、海流荷载模块、海冰荷载模块、地震荷载模块以及桩-土数字模块,实现海洋平台数字荷载模块程序开发。传统的冰疲劳荷载划分方法忽略了冰速、破冰周期以及平台固有频率相互关系的影响,难以满足冰区平台疲劳寿命精细评估需要。基于冰激平台存在结构共振和非共振两种基本振动形式,提出一种新的建立平台冰激疲劳寿命评估环境荷载模型。该模型考虑结构固有周期划分冰荷载破冰周期,能够有效保证工况划分时不会错过大部分结构冰激共振工况。2、海洋导管架平台数字结构模型研究提出空间复杂管节点结构空间相贯线向平面圆环的映射方程,并在此基础上提出统一的复杂管节点精细建模方法;研究复杂管节点数字化实现的关键技术和数字管节点统一建模流程,为复杂管节点结构的模块化设计提供理论模型;开发了海洋平台数字耦合系统分析程序,解决了ANSYS软件子模型法不能实现海洋平台管-实体单元耦合精细局部分析的难题;提出将复杂管节点沿管壁分成8个区块分别计算应力集中系数,开发了复杂管节点应力集中系数计算模块;研究了海洋导管架平台数字结构仿真的建模原则,建立了海洋平台荷载数字模型的系统框架,通过在数字模型中设置结构关键节点,开发了海洋导管架平台整体结构和局部精细结构的数字建模模块。3、海洋平台碰撞风险及倒塌分析模型研究基于船-平台碰撞系统模型,分析了近海导管架平台可能受到碰撞的船舶种类、平均速度、冲击荷载,进行了船-平台碰撞的风险研究,包括船舶的碰撞概率、损失能量、碰撞后果分析,并以胜利油田海域平台碰撞为例进行了社会风险评估和个人死亡率评估分析;考虑结构失效的动力非线性响应过程,以平台飞溅区桩柱为关键初始失效构件,建立了平台结构发生初始破坏的等效静力模型,基于瞬时加载法分析了平台结构局部突变而振动的动力响应过程,提出了海洋平台连续倒塌的动力响应分析详细流程,最后实现了海洋平台碰撞及倒塌分析模块开发。4、不确定环境下的平台延寿决策模型研究分析了平台全寿命周期成本,研究了平台运行的主要风险;从影响平台服役状态的工程因素、结构因素、荷载因素和风险因素四个维度进行分析和调整,构建阶层结构;采用模糊理论建立正倒值矩阵,综合专家意见计算各因素权重;引入凹陷因子、裂纹因子、腐蚀因子以及冰荷载因子对影响因素进行合理量化,建立海洋油田老龄平台延寿决策评分准则;采用逻辑运算计算综合评分,建立老龄平台延寿决策参考表,进而依据该表确定平台延寿基准期;利用决策模型对两座海洋平台进行延寿决策,并将其结果与传统评判结果进行了对比分析。研究结果表明,采用本模型能够更加精确地描述平台的动态经济寿命,为复杂不确定环境的老龄平台延寿决策提供了一种新的计算思路。5、海洋平台数字安全仿真系统开发构建了海洋平台数字安全仿真系统框架;将平台基础数据分为七类,完成了SASOS软件系统的数据库开发;实现了海洋平台数字安全虚拟仿真环境模块开发,该模块由几何动态库、图形动态库以及几何内核库三个动态链接库组成;开发了平台安全评估模块,该模块可实现平台结构完整性评估、维修决策评估、加固效果评估以及剩余寿命评估;开发了导管架平台数字安全仿真系统软件SASOS,软件通过访问其中的数据库模块,自动生成近海平台评估的荷载数字模型、整体结构数字模型、局部结构精细模型、结构服役损伤模型以及维修加固模型;SASOS软件共分为12个功能模块:项目管理、平台数据库、虚拟显示模块、数字荷载模块、数字结构模块、设计水平评估模块、极限承载评估模块、结构损伤评估模块、剩余寿命评估模块、碰撞风险评估模块、连续倒塌仿真模块、延寿决策模块;最后软件针对胜利油田的两座平台进行了工程示范应用评估。更多还原

【Abstract】 Digitalization of Offshore platform safety technology is not just a new concept. Although theoretical basis, technical data and engineering applications involved in it are built on the existing knowledge, digital safety simulation develops and integrates existing knowledge from a higher level and point of view of system theory and integration, thus it’s beneficial for mining and using various data of existing platforms more comprehensively, more deeply, and more effectively, performing simulation based structure safety analysis,which ensures the safe operation of platforms. It plays an active role in improving the safety and life-cycle management of our country’s offshore platform.Relied on a special issue of National High Technology Research and Development Program of China--"Offshore Aged Platform Life Extension Research", National Natural Science Foundation of China--"the Research on Life Prediction, Management Theories and Methods for the Aging Platform Life Extension Project", and Natural Science Foundation of Shandong Province--"Study on Offshore Structures Virtual Safety Theory and Its Application", in this paper the offshore fixed jacket platform is its study object, new idea about building digital safety technology systems of a marine engineering structure is proposed, and the research on jacket platform digital safety simulation and its application is carried out systematically. The studies in several aspects including offshore platform environment digital loads modeling, offshore platform digital structure modeling, offshore platform ice-induced fatigue load modeling, complex tubular joints modeling method, platform collision risk assessment, dynamic nonlinear analysis of platform progressive collapse, aged platform life extension decision-making model, platform digital safety simulation environment, technical systems of offshore platform safety assessment, marine structures digital safety simulation software development and so on, have made great progress, which can provide effectively technical support for the drilling and producing equipment safety of China’s offshore oil and gas resources. Main researches are summarized as follows:1. Study on offshore jacket platform digital load modelModeling steps of the marine platform digital load model is studied; system framework of marine platform digital load model is designed and the corresponding 6 digital load calculation modules are developed, i.e. sea wind load module, wave load module, ocean currents load module, sea ice load module, seismic load module and pile-soil digital module. Offshore platforms digital load module program development is achieved. Ice-induced fatigue load division method in the traditional approach misses mutual relations’impact among the ice speed, ice breaking cycle, platform natural frequency; thus it is difficult to meet the need of platform fatigue life fine assessment in ice zone. Based on two basic forms of structural resonance and non-resonant vibration existing in ice-induced platform, a new environmental load model of assessing platform ice-induced fatigue life is proposed. This model divides ice load ice-breaking cycle by considering the structure natural cycle; therefore it can effectively ensure that most of the structure ice-induced resonance working conditions will not be missed when they are divided.2. Study on offshore jacket platform digital structure modelThe equation mapped from intersecting line in structure space of tubular joints with complex space to circular planar ring is proposed, and on this basis, the uniform and fine modeling method for complex tubular joints is presented. The key technology for complex tubular joints to achieve digitalization and digital tubular joints unified modeling process are studied and a theoretical model is provided for complex tubular joints’modularized design. Offshore platforms coupling system analysis program is developed; and the difficult problem that offshore platform pipe-solid element coupling fine local analysis is not able to be achieved by ANSYS software sub-model method, is solved. The creative proposal that Stress concentration factor be calculated separately by dividing complex tubular joints into eight blocks along the tube wall is put forward, on which complex tubular joints stress concentration factor calculation module is developed. The modeling principles of offshore jacket platform digital structure simulation is studied, and a system framework of ocean platform loading digital mode is established; through setting up structures key nodes in the digital model, digital modeling modules for jacket platform integral structure and local fine structure are developed.3. Offshore Platform Collision Risk and collapse analysisBased on the ship-platform collision system model, ship types, average speed, shock loads involved in offshore jacket platform collision are analyzed; the study on risk of collision between ship and platform is conducted including the ship’s collision probability, loss of energy, collision consequence analysis, and social risk assessment and individual mortality assessment analysis is conducted by taking Shengli Oilfield sea area platform collision as an example. Considering the dynamic non-linear response processes of structural failure, taking cylinders in platform splash zone as key initial failure components, equivalent static model of platform structure happening initial destruction is established. Based on the instantaneous load method, dynamic response process of vibration caused by platform structure local mutation is analyzed and dynamic response detailed analysis process of marine platform continuous collapse is suggested.4 The platform life extension decision-making under uncertain environmentPlatform whole life cycle cost is analyzed and major risks of platform running are studied. Analysis and adjustment is conducted from four dimensions----engineering factors, structural factors, load factors and risk factors which affect platform service state, and hiberarchy structures are built; adopting fuzzy theory, positive inverted value matrix is established, and weight of each factor is calculated by integrating experts’advice. Introducing depression factor, crack factor, corrosion factor, as well as the ice load factor quantifies factors reasonably and establish marine oil aged platform life extension decision-making score criteria. Using logical computation calculates a comprehensive score, and establishes aged platform life extension decision-making reference tables, thereby based on the table to determine platform life extension reference period. Utilizing decision-making model, life extension decision-making for two marine platforms is proceeded and comparative analysis between the results and the traditional evaluation results is conducted. The study results indicate that using this model, the platform dynamic economic life is able to be described more accurately, and a new computing idea can be provided for aged platform life extension decision-making under complex and uncertain environment.5. Offshore Platform Digital Safety Simulation System DevelopmentOffshore platform digital safety simulation system framework is set up; digital platform data are divided into seven categories and SASOS software system database development is completed; offshore platform digital safety virtual simulation environment module development is achieved which is composed by three dynamic link libraries including the geometry dynamic library, graphics dynamic library and geometric kernel library;platform safety assessment module is developed which can achieve platform structural integrity assessment, maintenance decision evaluation, strengthening effect assessment and the remaining life assessment; and jacket platform digital safety simulation system software SASOS is developed; by visiting database module, this software can automatically generate offshore platform digital loads model, the overall structure digital model, the local structure fine model, the structure service damage model and maintenance and reinforcement model; SASOS software is divided into 12 functional modules: project management, platform database, virtual display module, digital load module, digital structure module, design level assessment module, ultimate loading evaluation module, the structure damage assessment module, residual life assessment module, the collision risk assessment module, progressive collapse simulation module, and life extension decision-making module. Finally, engineering demonstration application assessment is carried out for two platforms in Shengli Oilfield by this software.更多还原