深水大型半潜式天然气生产平台风险管理

Risk management of deepwater large semi-submersible natural gas production platforms

位于南海北部的陵水17-2气田半潜式天然气生产平台是国内首个1500 m水深、立柱内大容量储存凝析油的半潜式生产平台,为了识别其各系统的潜在风险并进行风险管理,利用HAZOP、SIL和基于熵权的贝叶斯网络方法,结合专家的经验,对该平台的常规和特有风险进行了分析评价。研究方法和步骤包括:①确定事件与事故的因果关系,建立贝叶斯网络;②进行事故致因分析,确定最大事故致因链;③开展敏感性分析,找出对事故发生概率影响最大的事件,为风险防控提供重要依据;④依据风险识别与分析结果,针对平台各子系统提出相应的风险防控建议。由此建立了该半潜式平台的风险管理流程,将平台划分为系泊、立管、平台上部(气体接收和分离、气体压缩、气体脱水和燃气、生产水、凝析油处理、排水管和火焰)、船体设施、生活区以及货物装卸区等11个区域,针对每一个区域进行HAZID分析,识别出平台火灾爆炸、烟气扩散、船舶碰撞、落物、逃生撤离救生、化学品泄漏以及凝析油储存和外输等风险源,并给出了主要风险的应对措施。结论认为,该项研究成果对于我国未来深水油气项目的风险管理具有重要的参考价值。

The semi-submersible production platform in the Lingshui 17-2 Gas Field of the northern South China Sea is the first domestic deepwater semi-submersible production platform(water depth 1500 m)with high-volume condensate oil stored in the vertical column.In order to identify the potential risks in each of its system and perform risk management,this paper analyzes and evaluates the conventional and special risks of this platform by means of HAZOP,SIL and entropy weight based Bayesian Network,combined with experts'experience.The research methods and procedures are as follows.First,determine the causal relation between the event and the accident,and establish the Bayesian Network.Second,analyze the causes of the accident and determine the maximum cause chain.Third,carry out sensitivity analysis to find out the event which has the greatest influence on the occurrence probability of the accident,so as to provide an important basis for risk prevention and control.Fourth,according to the risk identification and analysis results,propose risk prevention and control suggestions corresponding to each sub-system of the platform.In this way,the risk management process of the semi-submersible platform was established,in which the platform is divided into 11 zones,e.g.mooring,riser,upper platform(gas reception and separation,gas compression,gas dewatering and burning,production water,condensate oil treatment,drainage pipe and torch),hull facility,living zone and cargo working zone.Then,HAZID analysis was carried out on each zone.Finally,risk sources of the platform were identified,including fire and explosion,flue gas diffusion,ship collision,junk,escape,evacuation&rescue,chemical leakage,and condensate oil storage and transportation,and countermeasures to deal with the main risks were provided.In conclusion,the research results provide important reference for the risk management of deepwater oil&gas projects in China in the future.