基于马尔可夫的地面控制井下安全阀可靠性评估

为保障地面控制井下安全阀系统的安全运行,防止系统发生故障,建立了井下安全阀可修复系统的马尔可夫模型;针对系统设备构成复杂及共因故障等问题,基于β因子模型描述共因失效,同时将模型划分为3个独立模块,通过克罗内克积方法合并,评估系统可靠性;参照OREDA可靠性数据,定量求解井下安全阀系统可用度、可靠度以及稳态指标,研究模型中状态转移概率对系统稳态可用度的影响。研究结果表明:井下安全阀系统的可用度随时间增长而迅速到达稳态值;系统检修周期应小于2. 5 a;根据可靠性分析结果,运营方应考虑系统经济与可靠性间的博弈关系,合理优化系统冗余结构与维修周期管理,防止井下安全阀系统失效。

Markov based reliability assessment for surface controlled subsurface safety valve system

To ensure the safe operation of surface controlled subsurface safety valve system and prevent the failure of the system, a Markov model for the repairable system of subsurface safety valve was established. Aiming at the problems of complex equipment composition and common cause failure of the system, the common cause failure was described based on the β-factor model, meanwhile, the model was divided into three independent modules, and the reliability of the system was evaluated by merging with the Kronecker product approach. The availability, reliability and steady state indexes of the subsurface safety valve system were quantitatively calculated referring to the reliability data of OREDA, and the influence of state transition probability in the model on the steady state availability of the system was studied. The results showed that the availability of the subsurface safety valve system rapidly reached the steady state value with the increase of time. The overhaul cycle of the system should be less than 2.5 years. According to the results of reliability analysis, the operators should consider the game relationship between the economy and reliability, and rationally optimize the redundancy structure and maintenance cycle to prevent the failure of the subsurface safety valve system.