水下采油树控制回路贝叶斯-GO法可靠性分析

Reliability Analysis of Subsea X-mas Tree Control Loop by Bayesian-GO Method

为保证水下采油树控制系统的监测和控制回路生产运行功能正常,提出运用一种改良的贝叶斯网络与GO法相结合的方法对系统控制回路进行可靠性分析。根据正常工况和泄漏工况,对系统的生产回路和环空回路的各控制阀门的操作路径建立GO图。列出系统的控制回路框图,并按照对应GO模型转换成GO流程图。按照一定的映射规则,将GO图转换成对应的贝叶斯网络结构。根据贝叶斯法的前向和后向推理计算规则,得出控制回路在不同工况下各阀门的风险概率。分析结果表明,在深水环境的高压和高腐蚀性影响下采油树系统的控制功能会受到一定的影响,水下控制模块(Subsea Control Model,SCM)的失效率较高。

In order to ensure the safety and reliability of the monitoring and control functions of the X-mas tree control system,an improved Bayesian-GO method is used to analyze the reliability of the control circuit of the underwater tree system.According to the normal working condition and leakage working condition,a GO chart is established for the operation paths of the control valves of the production circuit and annulus circuit of the system.The block diagram of the control loop of the system is listed and converted into a GO flow chart according to the corresponding GO model.According to certain mapping rule,the GO chart is converted into a corresponding Bayesian network structure.According to the forward and backward reasoning calculation rules of the Bayesian method,the risk probability of each valve of the control circuit under different operation conditions is gotten.The analysis results show that the control function of the X-mas tree system is affected to some extent under the influence of high pressure and high corrosion in the deepwater environment,and the failure rate of the Subsea Control Module(SCM)is high.