【作者】 郑贤斌；

【导师】 陈国明；

【作者基本信息】 中国石油大学 ， 机械设计及理论， 2007， 博士

【摘要】 本文结合国家安全生产监督管理总局计划课题“油气管道结构安全运行数字化技术研究”。基于结构可靠性分析和维修决策理论,系统开展了老龄输油管道安全评估与维修决策关键技术研究,在管道模糊风险分析与安全评估新方法、老龄管道系统安全综合评估、老龄管道腐蚀可靠性分析、老龄穿跨越管道结构安全分析,以及老龄管道结构检测及维修规划等方面取得了较大的研究进展,主要的研究成果总结如下:1老龄输油管道系统安全综合评估体系研究鉴于老龄输油管道系统的高维性、复杂性、开放性及动态性等特征,从系统观点出发,提出了老龄输油管道复杂大系统的概念,按照孕育事故环境、事故致因和事故后果等理论进行老龄管道系统安全分析。基于老龄输油管道人--机--环境的系统安全问题,探讨了老龄输油管道的风险特征及安全综合评估的基本内容,确定了涵盖老龄管道系统的5大主要因素:第三方破坏、腐蚀、安全余量、误操作和自然灾害,构建了一个适于老龄输油管道较完整的安全指标体系。其中,从水文地质、地震和腐蚀方面,进行了老龄管道穿跨越工程的安全因素分析。基于老龄管道系统自然灾害的种类、影响与失效模式,将风险分析方法与结构的抗灾害能力相结合,探讨了集自然灾害、管内介质、人因环境以及预防和响应分析于一体的基线风险评估系统,从而有助于老龄管道系统自然灾害评估模式向新评估模式转变,为定量评估老龄管道结构安全可靠性奠定基础。2老龄输油管道系统安全可靠性评估方法研究鉴于目前管道安全可靠性分析方法存在的不足,提出了基于SCGM的模糊风险分析方法,为管道模糊风险分析的精细评估创造了新途径;综合考虑共性因素和个性因素,提出了一种基于故障树的管道安全模糊综合评价集成方法;通过将SPA引入管道安全系统评价领域,提出了一种全新的基于SPA安全综合评价模型。针对传统的平面静态评估方法所存在的不足,提出了基于CN综合评估及其PCN的发展趋势评估是一种立体的、单样本的、动态的和可再评估方法。从内部检测信息获取方式的不同,提出了将老龄管道分为不可用内部检测装置的管道和可用内部检测装置的管道。综合当前所提出的最新的动态安全评估方法,针对上述两类老龄管道分别提出了“合于使用”的两类可靠性评估方法。基于老龄管道各种失效模式,开展了老龄管道腐蚀可靠性分析,对各参数间的相互作用对老龄管道系统可靠性的影响及其敏感性分析;建立了腐蚀疲劳寿命模型;综合考虑在线检测数据的不精确性与管道材料特性、操作载荷以及由腐蚀增长率导致管线状态的不确定性,提出了一种基于模糊概率人工神经网络的老龄输油管道可靠性评估模型。采用可靠性分析方法,结合“合于使用”评估,给出了腐蚀管道动态失效概率评估方法。3老龄输油管道穿跨越段的结构安全分析研究考虑到在地质不稳定区受滑坡、沉陷、坍塌等自然灾害破坏性影响,根据弹性地基梁理论建立了土壤沉陷形成管跨段力学计算模型,其中管土交互作用通过非线性弹簧单元模拟,采用有限元分析方法计算出了在不同跨长、不同埋深、不同壁厚和不同外径等情况下应力分布状况,并由此给出了管道失效的临界长度。考虑埋地管道与土壤之间的非线性交互,建立弯头地段埋地管道模型,对弯管的弯头、过渡段和公路埋设段进行了应力分析;建立了考虑管土交互的地震载荷作用下管道响应有限元计算模型,并从地震断裂带和地震波作用下的管道进行结构分析,为陆上埋地管道抗震性能安全评估提供了重要的参考依据。4老龄输油管道结构检测及维修规划研究考虑检测与维修效果的可靠性分析模型是老龄管道时变可靠性分析的基础,提出了多种考虑检测与维修效果的可靠性分析模型:寿命模型、失效率模型和寿命可靠性模型等,对老龄管道的维修效果进行分析。描述和对比老龄管道结构衰退和维修模型,考虑结构衰退过程所存在的不确定性,从不完备性考虑,将半Markov模型、统计过程或与时间相关的可靠性指标作为失效率函数建立了动态衰退模型,提出了一个有助于优化评估老龄管道的修复、更换、检测和条件评估的整体框架。考虑检测仪器和维修准则所存在的不确定性,采用Markov过程给出了新缺陷的检测与维修规划,同时结合“合于适用”评估方法,开展了老龄输油管道完整性条件评估下的费--效分析,提出优化老龄管道较完整的维修方案,从而确保老龄管道经济安全的运行。更多还原

【Abstract】 The techniques for aging oil pipeline including risk analysis, safety comprehensive assessment, reliability analysis, and decision-making for maintenance, et al, were studied in this dissertation; and the safety assessment technique was introduced in the safety inspection and management for aging oil pipeline, which provided a kind of powerful safety assurance technology for the safe operation of aging oil pipeline. In this paper, structural safety assessment technique and decision-making for maintenance technology of aging long distance oil pipeline were lucubrated based on the project“Research on Digitized Technology of Safe Operation of Oil&Gas Pipeline Structure”listed by STATE ADMINISTRATION OF WORK SAFETY. Considering the randomness, fuzziness, nondeterminacy, et al; based on stochastic reliability theory; an integrated technology system of structural safety reliability analysis and control decision of aging oil pipeline was established primarily, including pipeline structural corrosion damage, dynamic reliability analysis, durability assessment, residual life prediction, inspection, and maintenance decision&control, et al. It could be an guidance for the aging oil pipeline safe operating management; and under its help, pipeline inspection cycle be optimized, life-span cost be reduced, the aging pipeline’s safety, reliability, fitness, durability and integrity be ensured, and aging pipeline real-time risk supervision be achieved, and as a result it helps to improve pipeline safety and reliability during the service life. The main work is summarized as follows now:1 Research on Safety Comprehensive Assessment System for Aging Oil Pipeline Considering such characters of aging oil pipeline system as super-dimensionality, complexity, opening, dynamic, et al, the concept of great complex system of aging oil pipeline system was provided, and aging pipeline system safety was analyzed according to those theory: pregnanting accident-environment, accident-cause, accident-result, et al. The basic content of the character of aging oil pipeline’s risk and safety comprehensive assessment were discussed based on the human-machine-environment system safety of aging oil pipeline; and five main factors which cover nearly all aspects of aging pipeline system were determined, including the third-party damage, corrosion, safety allowance, false operation and natural disaster; and an integrated safety index system for aging oil pipeline was set up. An engineering assessment index system of aging oil pipeline’s spanning section was presented in the view of hydrogeology, earthquake and corrosion. The factors that influence the aging pipeline including types of natural disasters, effect mode and failure mode were introduced, the risk assessment methods were discussed and the system framework considering Natural Disaster, Content, Human/Environment and Prevention Assessment is given. Natural disaster assessment technique for aging pipeline system was studied systemically in this paper, and a natural disaster(such as flood, subsidence, landslide, wave-current, ice force, seism, fire, explosion, et al) assessment technique framework was founded. Doing research on comprehensive disaster assessment technology by combining the risk analysis method with the structural ability to resist disaster, which helped to convert the traditional assessment model of the aging pipeline natural disaster safety assessment into the modern one, and set up the foundation of quantitative assessment of aging pipeline structural reliability.2 Research on Safety Reliability Method for Aging Oil Pipeline SystemConsidering the deficiency of current safety reliability analysis methods, a fuzzy risk analysis method based on SCGM(Simple Center of Gravity Method) was presented, which created a new way for precise assessment of pipeline fuzzy risk analysis; and considering both common factors and individual factors, a integral method of the fuzzy comprehensive evaluation for oil pipeline failure based on fault tree was brought forward; a new safety comprehensive assessment model based on SPA(Set Pair Analysis) was offered by introducing SPA to the field of pipeline safety system assessment. Taking the disadvantage of traditional plane state evaluation method into account, comprehensive evaluation based on CN(Connection Number) and developing trend evaluation based on PCN(Partial Connection Number) were proposed firstly, and proven to be a three-dimensional, single specimen, dynamic, and reevaluating method.According to the difference of the internal inspecting information obtaining manner, the aging pipeline was classified for the first time as the non-internal inspection pipeline and the internal inspection one. Integrated with the up-to-date dynamic/variable weight safety assessment technique, two kinds of reliability assessment methods based on fitness for purpose were put forward separately for these two different kinds of aging pipelines. Based on aging pipeline various failure models, aging pipeline corrosion reliability analysis was carried out, and both the influence on aging pipeline system reliability by the reciprocity of all parameters and its sensitivity analysis was studied in detail. The corrosion fatigue life model was established. A fuzzy probabilistic neural network model for reliability assessment of aging long distance oil pipeline was put forward, considering the imprecision of the information provided by in-line inspection, uncertainties associated with pipeline material properties, operational loads, and the rate of corrosion growth. The dynamic failure probability assessment method for corrosion pipeline was given by the reliability analysis technique, combining the assessment method of“fitness for purpose”. 3 Research on the Structural Finite Element Analysis for Aging Oil Pipeline’s Crossing and Spanning SectionTaking the fact into account that the devastating impact of such natural disaster as slope, subsidence, sedimentation, et al, in unsteady geologic region; based on the elastic foundation beam theory, the mechanical model of pipe-soil subsidence was established. The pipe-soil interaction was simulated as nonlinear spring element; and the stress distribution under such different circumstances as different spanning length, different buried depth, different wall thickness, different external diameter, et al, was calculated by the finite element analysis; by which both the maximum and the minimum Mises stresses and their corresponding positions were gained; therefore, the critical spanning length which would result in pipeline failure was gained, too. Considering the fact that the crossing highway was one of the dangerous belts for buried pipeline, the elbow part of buried pipeline was modeled, and the stress of the syphon’s elbow, transition and the highway’s buried part was analyzed; the finite element model of pipeline response to seismic load was set up by considering the pipe-soil interaction. And as a result, the safety assessment of onshore aging pipeline seism-resisting capability was well guided.4 Research on Structural Inspection and Maintenance Scheme of Aging Oil Pipeline The reliability analysis model with the effect of inspection and maintenance considered was the basis of aging pipeline time-dependent reliability analysis. Many reliability analysis models with the effect of inspection and maintenance considered were put forward including life model, failure rate model, life reliability model, et al, which help to the analysis of aging pipeline maintenance effect.Describing and contrasting the structural deterioration model and the maintenance model of aging pipeline, considering the uncertainties existing in the structural deteriorating process and the imperfectness, regarding the semi-Markov model, statistical process or the time-dependent reliability index as the failure function, the dynamic deterioration model was then established. A whole framework which helped to optimizing and evaluating the large aging pipeline’s maintenance, replacement, inspection and condition assessment was given.Considering the uncertainties of inspection instruments and maintenance rules, a new inspection and maintenance planning for defects was given by adopting the Markov process. At the same time, combining the“fitness for purpose”assessment, the optimum integrity management scheme which plans to repair the aging pipeline was established, through the cost-effect analysis based on the integrality assessment of aging oil pipeline. Therefore, the economical and safe operation of the aging pipeline would be guaranteed.更多还原