海底复杂环境下深水采油树系统失效机理及故障诊断方法研究

深水采油树系统是海洋石油水下生产系统最重要的设备之一，在海底复杂环境下，其故障的发生在破环海洋生态环境的同时，给生产方造成难以估计的经济损失。本项目研究海底复杂环境下深水采油树系统故障发生的类型、模式、失效机理和动态演变规律，提出瞬态故障、间歇故障和永久故障状态转移的理论建模新方法，研究揭示非永久故障对系统失效的影响规律；研究有限元分析模型与贝叶斯网络的融合方法，提出控制流程向贝叶斯网络映射的新思路，建立深水采油树系统的故障诊断模型，探明故障判定规则、传播路径、定位和证据冲突分析等问题；考虑剩余寿命、费用、停机时间和操作风险等关键因素，建立以可靠性为中心的维修与预防性维护多属性决策模型，为操作人员制定最佳维修与预防性维护方案提供科学合理的依据。本项目的研究成果不仅可以丰富贝叶斯网络和故障诊断的理论和内容，还能为我国海洋石油勘探开发保驾护航，具有重要的理论意义和工程应用价值。

A deepwater Christmas tree system is one of the most significant equipment of offshore oil subsea production systems. In submarine complex environment, the faults of deepwater Christmas tree systems would cause marine ecological environment destruction and enormous economic losses. Given this situation, types, modes, failure mechanism and dynamic development law of faults of deepwater Christmas tree systems in submarine complex environment are investigated, a state transition modelling methodology of transient, intermittent and permanent faults is proposed, and effects of non-permanent faults on system failure are analyzed. A method of fusion of finite element analysis models and Bayesian networks is studied, a method of mapping from control flow charts to Bayesian networks is also proposed, and fault diagnosis models of deepwater Christmas tree systems are established. Fault decision rules, fault propagation path search method, fault localization method, and conflict analysis method of evidence are researched. A reliability-centered repair and preventive maintenance decision-making model of deepwater Christmas tree systems taking account of remaining useful life, cost, downtime, and operating risk are developed. It can provide scientific basis of decision making for rational repair and maintenance. Therefore, this study contributes to the theories of Bayesian networks and fault diagnosis, improves the safety of offshore oil exploration and exploitation, and is of great significance in theory and practical value in engineering.