基于RBI技术的油气集输系统储罐风险分析

On the risk analysis for storage tanks in oil-gas gathering and transportation system based on RBI technology

在油气集输系统中,储罐的使用年限不一,老化程度不同,其风险也存在差异。因此,在执行储罐检验维修计划前应对各储罐的风险有清楚的认知,以科学合理地安排基于风险的储罐检验计划,提高效率,节约资源。提出了基于RBI技术的油气集输系统储罐风险分析方法,通过定性RBI分析筛选出高风险的储罐,再针对高风险储罐的不同部位进行定量RBI分析。实例分析结果表明,该油气集输系统中1、5、7、9号储罐风险中高,且储罐的底板失效风险高于壁板,其中5号储罐的底板失效风险最高,与其超期服役的事实相符。由此可知,该方法的风险分析结果符合现场实际,且结果层次清晰地显示了不同储罐及不同部位的风险,可据此改进储罐检验计划。

This paper intends to propose a new risk analysis method for storage tanks in oil-gas gathering and transportation system based on the RBI technology in hoping to optimize the oilgas tank inspection and maintenance by identifying and determining the risk levels of such storage tanks. As is known,RBI analysis technology can help to establish a basic information database and the hazard analysis foundation before the risk analysis is done. And,then,it would be possible to pick up the highest risk-facing storage tanks according to the general procedure of the RBI-based risk analysis. In addition,the probability of the failure can also be found by adding such factors,as the equipment factor,the damage factor,the inspection factor,the condition factor,the process factor as well as the mechanical design factors.What is more,the API 581 standard can also help to find the problem tanks by joining the API 581 standard with the inspection and sustenance recordings. And,for this purpose,both qualitative analysis and quantitative analysis can both be highly useful.For example,qualitative analysis can help to find the failure by adding the equipment-function factors,the damage factors,the inspection factors,the conditioning factor,as well as some other mechanical design factors. At the same time,the consequential damage and failure can also be taken as the sum of the aforementioned factors with the burning damage being the primary factor to be concerned about. On the other hand,quantitative analysis has also to be done for the different parts of the high-risk storage tanks. For such analysis,it is also of equal importance to make clear the cause of failure and the consequence of failure in a detailed way,for the function failure may often result from a number of failure factors and / or varied damage factors with some one caused by the corrosion of some other parts. The results of our case study indicate that the case study samples of storage tanks1#,5#,7# and 9# just stay in the intermediate state between the middle and high risk stages. What is more,it is also necessary to point out that the failure risk of their baseboards can be much higher than that faced by the wall ones,which may imply that the baseboard of storage tank 5# is in the brink of failure. In conclusion,the results we have gained with the proposed method prove to be in accord well with the practical condition. And,simultaneously,it also shows that only 20% of the storage tanks stay at the higher risk while the others remain at the relatively lower risk sage. Therefore, the storage tanks should be inspected and checked in an optimized way so as to save the material resources and enhance the usability.