基于LOPA方法的海上油气设施火气系统SIL定级研究

摘要

石油化工行业通常采用保护层分析方法(LOPA)对安全仪表系统进行安全完整性SIL定级,但是目前还缺乏针对火气系统(FGS)进行SIL定级的具体方法.本文首先根据FGS风险降低要求,在常规风险降低概念基础上提出了新的适用于FGS的风险降低指标,并利用事件树(ETA)方法对不同火气灾害场景类型进行了综合评估,解决了传统LOPA方法只关注最坏场景的保守风险控制策略的弊端,而改进LOPA技术可以对FGS场景实现量化的风险分配.最后针对某海洋平台原油泄漏的实际生产案例,采用所提出的改进LOPA定级技术对FGS的安全可用性进行了定量化分析,实现了对海上油气风险控制设施的优化配置.%Layer of protection analysis (LOPA) is frequently and widely used to determine safety integrity level (SIL) of safety instrumented system in petrochemical industry.However,the detailed SIL determination techniques for fire and gas system (FGS) are still rarely known.This paper,in view of FGS risk reduction requirements,proposes a new risk reduction target applicable for FGS based on conventional risk reduction concepts,and makes comprehensive evaluations on various FGS accident scenarios through event tree analysis (ETA),which conquers conservative risk control strategy drawbacks of conventional LOPA method that only concentrates on the worst case.This improved LOPA technique can realize quantitative risk allocation for FGS scenarios.Moreover,this improved LOPA based SIL determination technique was used to conduct quantitative analysis on the safety availability of FGS of one offshore platform where oil leakage has occurred.The results show that it can achieve optimal allocation for offshore oil/gas risk control facilities.