Process safety management lessons learned from a fire and explosion accident caused by a liquefied petroleum gas leak in an aromatics reforming unit in Taiwan

A severe fire and explosion accident was caused by a liquefied petroleum gas leak in Taiwan in 2019. This accident resulted in the loss of approximately US$3.5 billion in output value due to a one-and-a-half-year shutdown after the accident; however, no casualties were recorded at the accident scene. An analysis of the accident pipelines demonstrated that the pipeline leak had been caused by hydrochloric acid corrosion. Cause analysis based on the accident timeline, fault tree analysis, and causal factor charting indicated inadequacies in five elements of process safety management (PSM) namely mechanical integrity (MI), management of change, emergency planning and response, process hazard analysis (PHA), and process safety information (PSI) as the root causes of the accident. Furthermore, insufficient PSI (i.e., a lack of comprehensive understanding regarding corrosion mechanisms) was deemed to have been the core problem leading to the accident. This accident revealed common shortcomings that are often overlooked in PSM implementation in Taiwan; thus, the present research can serve as a vital reference for improving PSM programs in Taiwan.     

油气管道周边区域划分与距离设定研究

为合理评估并有效控制管道与周边区域的相互影响,提出1种油气管道周边区域划分与距离设定方法。通过数据统计与事故案例分析,归纳了油气管道安全运行面临的4项问题,结合管道与周边区域相互影响类型及范围,提出将周边区域沿管道中心线依次划分为管道通行区、规划控制区和应急响应区。根据法律规定、实际事故后果影响范围和典型事故后果数值计算结果,提出了上述3个区域的距离设定原则与计算方法,并针对当前油气管道周边区域管理存在的问题提出了分区域管控建议。研究结果表明:所提出的方法有助于控制管道与周边区域的相互影响,保障管道安全运行和周边区域公共安全。     

Risk management of cost consequences in natural gas transmission and distribution infrastructures

A critical aspect of risk management in energy systems is minimizing pipeline incidents that can potentially affect life, property and economic well-being. Risk measures and scenarios are developed in this paper in order to better understand how consequences of pipeline failures are linked to causes and other incident characteristics. An important risk measure for decision-makers in this field is the association between incident cause and cost consequences. Data from the Office of Pipeline Safety (OPS) on natural gas transmission and distribution pipeline incidents are used to analyze the association between various characteristics of the incidents and product loss cost and property damage cost. The data for natural gas transmission incidents are for the period 2002 through May 2009 and include 959 incidents. In the case of natural gas distribution incidents the data include 823 incidents that took place during the period 2004 through May 2009. A two-step approach is used in the statistical analyses to model the consequences and the costs associated with pipeline incidents. In the first step the probability that there is a nonzero consequence associated with an incident is estimated as a function of the characteristics of the incident. In the second step the magnitudes of the consequence measures, given that there is a nonzero outcome, are evaluated as a function of the characteristics of the incidents. It is found that the important characteristics of an incident for risk management can be quite different depending on whether the incident involves a transmission or distribution pipeline, and the type of cost consequence being modeled. The application of this methodology could allow decision-makers in the energy industry to construct scenarios to gain a better understanding of how cost consequence measures vary depending on factors such as incident cause and incident type.     

Carbon dioxide pipelines: A statistical analysis of historical accidents

Carbon dioxide pipeline is an essential carrier in carbon capture, utilization, and storage (CCUS). Statistically revealing the accident rate and risk of carbon dioxide pipelines is conducive to integrity management. Based on 112 accident records collected from Pipeline & Hazardous Materials Safety Administration, this work analyzes the frequency, rate, and risk of accidents. In addition, the impact of relevant factors on risk is further discussed. Some primary conclusions are as follows: (1) For carbon dioxide pipelines, the leak is the leading form of accident. Most carbon emissions are generated in the form of leakage, but economic losses are mainly generated in other forms. (2) The pipelines that have been in service for 0–10 years have the highest frequency of accidents and the highest proportion of carbon emissions, but the pipelines that have been in service for 11–20 years have caused the most economic losses. (3) Among the accident causes, the number of accidents caused by equipment failure is the highest, while the economic loss caused by natural force damage is the highest, and the carbon emission caused by material failure is the highest.     

天然气管道完整性管理探析

通过对国内外天然气管道事故的统计和分析,指出了对天然气管道进行完整性管理的重要性;在此基础上,简要介绍了管道完整性管理方法,着重探讨了天然气管道完整性管理的流程和环节,包括管道潜在危害辨识、管道数据信息搜集与分析、管道风险评价、管道完整性评价、完整性评价响应和减缓措施,并进一步说明了天然气管道完整性管理的实施方法;最后,给出了在我国开展天然气管道完整性管理的必要性和建议.     

Accident investigation in the Norwegian petroleum industry - Common features and future challenges

In their regulations, the Petroleum Safety Authority Norway (PSA) states that the companies responsible for oil and gas exploration and production activities in Norway shall record and investigate accidents and serious incidents. This paper introduces a general model for the accident investigation process in the Norwegian petroleum industry, and presents some results derived from a comparative study of causal factors identified in offshore accident investigation reports from 2002 to 2006. The paper also offers a discussion of the improvement potential in the use of investigation methods. Finally, a discussion of future challenges in accident investigations is provided.     

Integrated dynamic risk assessment of buried gas pipeline leakages in urban areas

In urban areas, buried gas pipeline leakages could potentially cause numerous casualties and massive damage. Traditional static analysis and dynamic probability-based quantitative risk assessment (QRA) methods have been widely used in various industries. However, dynamic QRA methods combined with probability and consequence are rarely used to evaluate gas pipelines buried in urban areas. Therefore, an integrated dynamic risk assessment approach was proposed. First, a failure rate calculation of buried gas pipelines was performed, where the corrosion failure rate dependent on time was calculated by integrating the subset simulation method. The relationship between failure probability and failure rate was considered, and a mechanical analysis model considering the corrosion growth model and multiple loads was used. The time-independent failure rates were calculated by the modification factor methods. Next, the overall evolution process from pipeline failures to accidents was proposed, with the accident rates subsequently updated. Then, the consequences of buried gas pipeline accidents corresponding to the accident types in the evolution process were modeled and analyzed. Finally, based on the above research, dynamic calculation and assessment methods for evaluating individual and social risks were established, and an overall application example was provided to demonstrate the capacity of the proposed approach. A reliable and practical theoretical basis and supporting information are provided for the integrity and emergency management of buried gas pipelines in urban areas, considering actual operational conditions.     

EU initiative on the control of major accident hazards arising from pipelines

The European Council and the Parliament recognised that pipeline accidents had occurred in Europe and worldwide, which clearly indicated the `major accident hazard' potential of pipelines. The present paper presents an overview of the Community Policy on the control of major accident hazards arising from pipelines, summarises the Commission review/assessment of existing legislation on pipelines within the Member States and outlines the principles on which a possible EU initiative should be based. The review has shown that many Member States do not have comprehensive `major accident hazard' legislation in place for pipelines and therefore an EU initiative would complete existing industrial risk management legislation, based on the `precautionary principle'.     

An urban pipeline accident model based on system engineering and game theory

Urban pipeline accidents are caused by complex social-technical factors, in which urban communities and pipeline systems are involved. Such accidents can thus be investigated from the viewpoint of system engineering. System-Theoretic Accident Model and Processes (STAMP) is a systemic method for safety assessment, which has been adopted in many domains. This approach can provide deep insights of accident causes by considering direct and indirect factors. Meanwhile, competition and cooperation between stakeholders in accidents are observed. Therefore, these parties can also be analyzed with the game theory. That is, stakeholders in STAMP can be regarded as players in game. The aim of this paper is to provide a new insight to analyze urban pipeline accidents by considering both STAMP and game theory. In this paper, we proposed an accident model for urban pipelines, with a case study of China-Qingdao pipeline accident occurred in 2013. We concluded that accident reasons can be investigated in-depth and lessons can be learned from analyzing causal factors by using STAMP. Based on results generated from STAMP, we applied the game theory to analyze roles that government and companies act in the China-Qingdao urban pipeline accident. The results show that current punishment and incentive systems are incomplete, lacking of the driving force and constraining force for the stakeholders involved in the accident.     

由“7·28”南京丙烯管道爆燃事故探讨我国地下管道存在的安全问题

＂7·28＂南京丙烯管道爆燃事故和近期发生的一系列管道事故反映出我国在地下管道安全方面存在的问题。在事故原因分析与共性问题探讨的基础上,结合欧美国家在管道安全管理中的成功做法,从加强法制建设、合理规划城市布局、进行重大危险源普查并建立监测监控系统、强化城镇地面开挖施工安全管理、加强风险沟通提高公众应急能力等方面提出了对策建议。     

Root cause analysis of an old accident in an explosives production plant

Twenty-six years ago, a massive accident occurred in the Semtin explosives plant in Czechoslovakia. The results of investigations which were carried out (but kept confidential at the time) were made available after 1989, but have not been published in a summarized form to date. Reopening of the results of old investigations and application of root cause analysis deepens our understanding of accident causes and leads to the conclusion that, according to today’s standards, the analysis was not completed at the time of the accident and therefore neither some of the practical aspects of the event nor the social, professional, and political climate it should have exposed have ever been fully understood. New analysis shows that plant safety management had decayed. The results demonstrate as well how substantial a shift has occurred in the understanding of causes and in performing and organizing their analyses during the elapsed quarter-century. The new examination employs a few innovations of root cause analysis. A tight connection between the analysis and the assumptions about the structure of safety management of investigated processes will be underlined. Suitable illustration will be proposed. Detail requirements on the form and content of a root cause map will be specified. Finally it is shown that even the root cause analysis has its limitations and that it may not be sufficient to finish the investigation of causes satisfactorily. This motivates for the identification of levels of causes which underlie the root causes.     

城市地下空间管道施工坍塌事故行为原因研究

为了进一步了解城市地下空间管道施工坍塌事故发生的原因,笔者运用行为安全"2-4"模型事故致因分析方法分析了27起典型的管道施工坍塌事故,分析得出17类共109个不安全动作和6类共34个不安全物态,不安全动作中发生率较高的是不按要求对基坑放坡和加固、未对作业人员安全教育培训或者培训不到位以及施工前未进行风险识别或者识别不到位,并对这3方面不安全动作进行进一步分析;不安全物态中发生率较高的是未加支撑的基坑侧壁、存在淤泥和松软土质结构的开挖层。得出安全知识不足7类共58项,安全意识的淡薄,对于生产主管主要体现在雇佣临时工,施工现场作业人员则体现在不注意环境周围存在的安全隐患;得出安全管理体系的欠缺9类共88项,因安全生产规章制度缺乏或制度不合格导致安全管理体系欠缺占比最大,因无安全技术交底或技术交底不到位导致安全管理体系的欠缺居于第二位,施工前未进行风险识别或者识别不到位在27起事故中也出现12次,也是安全管理工作中不可忽视的因素。     

Major hazard pipelines: a comparative study of onshore transmission accidents

Failures of pipelines conveying dangerous substances can pose major risks. Identification of pipeline hazards associated with the different pipeline system functions is essential for risk analysis and historical data are of great importance. Incident data are analysed, following a review of official sources, by failure mechanism, size and function of the systems in two types of transmission networks around the world, i.e. natural gas and hazardous liquids. The development of the networks and the reporting criteria used by the official sources for the collection of incidents in the last twenty five years have shown remarkable differences. The performance of both gas and liquid transmission lines in Europe, the US and the former Soviet Union in terms of failures has shown a progressive improvement but the extent of consequences following gas releases and oil spillages have not shown any change in the last fifteen years. External interference is not always the predominant cause of failures in all systems depending also on pipe size. Failures with casualties in gas transmission have not shown any decrease over the last decade and there is a clear indication that many are connected with the parts and functions other than the main body of the pipeline. A comparison between European and US gas frequency data, derived under common constraints, shows that valuable information can be lost when criteria for incidents collection are only limited to the body of the pipeline.     

Incident tree model and incident tree analysis method for quantified risk assessment: An in-depth accident study in traffic operation

Fault tree analysis (FTA) is a logically structured process that can help identify potential causes of system failure before the failures actually occur. However, FTA often suffers from a lack of enough probabilistic basic events to check the consistency of the logic relationship among all events through linkage with gates. Sometimes, even logic relationship among all events is difficult to determine, and failures in system operation may have been experienced rarely or not at all. In order to address the limitations, this paper proposes a novel incident tree methodology that characterizes the information flow in a system instead of logical relationship, and the amount of information of a fuzzy incident instead of probability of an event. From probability statistics to fuzzy information quantities of basic incidents and accident, we propose an incident tree model and incident tree analysis (ITA) method for identification of uncertain, random, complex, possible and variable characteristic of accident occurrence in quantified risk assessment. In our research, a much detailed example for demonstrating how to create an incident tree model has been conducted by an in-depth analysis of traffic accident causation. The case study of vehicle-leaving-roadway accident with ITA illustrates that the proposed methodology may not only capture the essential information transformations of accident that occur in system operation, but also determine the various combinations of hardware faults, software failures and human errors that could result in the occurrence of specified undesired incident at the system level even accident.     

An integrated methodology to manage risk factors of aging urban oil and gas pipelines

Aging urban oil and gas pipelines have a high failure probability due to their structural degradation and external interference. The operational safety of the aging urban oil and gas pipeline is challenged by different hazards. This paper proposes a novel methodology by integrating an index-based risk evaluation system and fuzzy TOPSIS model for risk management of aging urban oil and gas pipelines, and it is carried out by evaluating the priority of hazards affecting pipeline safety. Firstly, the hazard factors of aging urban oil and gas pipelines are identified to establish an index-based risk evaluation system. Subsequently, the fuzzy TOPSIS model is employed to evaluate the importance of these hazard factors and to decide which factors should be managed with priority. This work measures the importance of a hazard factor from three aspects, i.e. occurrence (O), severity (S) and detectability (D), and the weights of these three parameters are determined by a combination weight method. Eventually, the proposed methodology is tested by an industrial case to illustrate its effectiveness, and some safety strategies to reduce the operational risk of the pipeline are presented. The proposed methodology is a useful tool to implement more efficient risk management of aging urban oil and gas pipelines.     

基于毕达哥拉斯模糊贝叶斯网络的海底管道泄漏风险分析*

为分析海底管道运行中存在的泄漏风险,提出1种基于毕达哥拉斯模糊数与贝叶斯网络的风险评估模型。首先,通过毕达哥拉斯模糊数转换专家定性评价,拓展专家意见模糊范围;然后,结合主客观组合赋权法,利用毕达哥拉斯梯形爱因斯坦混合几何算子（PTFEHG）实现专家意见的聚合;最后,通过贝叶斯网络的推理与敏感性分析,计算海底管道泄漏风险的失效概率,并辨识关键风险因素。研究结果表明:该方法可以结合专家意见对海底管道泄漏风险进行定量分析,并识别导致泄漏事故的关键风险因素,对海底管道安全管理具有指导意义。     

A modified accident analysis and investigation model for the general aviation industry: Emphasizing on human and organizational factors

IntroductionCurrently, there is a lack of specific analytical tools for general aviation accidents (GAAs). This has led to loopholes in the prevention of GAAs.MethodsA Swiss Cheese model for general aviation (SCM-GA) is proposed to identify the human and organizational factors involved in GAAs. In the proposed SCM-GA, 5 categories, 45 subcategories, a general aviation safety management system (GA-SMS) and safety culture were developed based on the classic accident causation models combined with the laws and regulations and safety management practices in the general aviation industry.ResultsOne GAA was analyzed using SCM-GA. The human and organizational causes revealed by SCM-GA were more complete than the causes revealed through the accident report. The identification results of the deficiencies in the subcategories of GA-SMS and the safety culture were more consistent with the requirements in the general aviation laws and regulations than the organizational factors in the accident report. Based on the subcategories of SCM-GA, 41 GAAs that occurred between 1996 and 2010 in China were statistically analyzed and χ² test analyses were performed to estimate the statistical strength of the association between two adjacent subcategories of SCM-GA. The results showed that two adjacent subcategories of SCM-GA were significantly associated. They helped to determine the hidden problems in the accident report based on the path of accident.ConclusionsSCM-GA is an accident analysis tool that can comprehensively analyze the human and organizational deficiencies involved in GAAs. The accident causes revealed by SCM-GA were more consistent with the general aviation safety management practices.Practical applicationsGeneral aviation companies should establish their own GA-SMS and safety culture based on the subcategories developed herein. Using SCM-GA for routine safety inspection and accident investigation will help the management and the staff make effective safety decisions to effectively prevent GAAs.     

Risk analysis for oil & gas pipelines: A sustainability assessment approach using fuzzy based bow-tie analysis

Vast amounts of oil & gas (O&G) are consumed around the world everyday that are mainly transported and distributed through pipelines. Only in Canada, the total length of O&G pipelines is approximately 100,000 km, which is the third largest in the world. Integrity of these pipelines is of primary interest to O&G companies, consultants, governmental agencies, consumers and other stakeholder due to adverse consequences and heavy financial losses in case of system failure. Fault tree analysis (FTA) and event tree analysis (ETA) are two graphical techniques used to perform risk analysis, where FTA represents causes (likelihood) and ETA represents consequences of a failure event. ‘Bow-tie’ is an approach that integrates a fault tree (on the left side) and an event tree (on the right side) to represent causes, threat (hazards) and consequences in a common platform. Traditional ‘bow-tie’ approach is not able to characterize model uncertainty that arises due to assumption of independence among different risk events. In this paper, in order to deal with vagueness of the data, the fuzzy logic is employed to derive fuzzy probabilities (likelihood) of basic events in fault tree and to estimate fuzzy probabilities (likelihood) of output event consequences. The study also explores how interdependencies among various factors might influence analysis results and introduces fuzzy utility value (FUV) to perform risk assessment for natural gas pipelines using triple bottom line (TBL) sustainability criteria, namely, social, environmental and economical consequences. The present study aims to help owners of transmission and distribution pipeline companies in risk management and decision-making to consider multi-dimensional consequences that may arise from pipeline failures. The research results can help professionals to decide whether and where to take preventive or corrective actions and help informed decision-making in the risk management process. A simple example is used to demonstrate the proposed approach.     

国外油气管道安全管理经验及启示

近年来,我国油气管道发展迅猛,管道数量激增;上世纪70!80年代修建的管道逐渐进入老龄化,管道事故呈上升趋势。文章对美国、加拿大和欧盟国家油气管道的发展现状和事故情况进行了介绍,重点对以美国为代表的国外油气管道安全管理先进经验进行了分析,并针对当前我国油气管道安全管理的形势和问题,提出了一些建议。