基于故障树与贝叶斯网络的钻井井塌事故的定量分析

井塌事故在钻井过程极其常见,由于钻井液、井身结构等设计不合理,以及钻井过程的误操作均会造成井塌的发生,其后果主要是造成卡钻、卡套管等事故,严重时造成井眼毁坏。为了对井塌事故进行危险性分析,采用贝叶斯网络与故障树相结合的方法,避免传统故障树方法的局限性。首先对井塌事故的所有危险因素进行辨识建立故障树,然后将故障树转化为贝叶斯网络,建立条件概率表,运用贝叶斯网络的推理能力对井塌事故进行危险性分析。对井塌事故各基本事件概率分布的计算分析结果表明,考虑事件的多态性,综合利用故障树分析法和贝叶斯网络法能有效提高井塌事故分析的有效性,推算出井塌事故概率分布更为准确。     

Dynamic safety analysis of process systems by mapping bow-tie into Bayesian network

Among the various techniques used for safety analysis of process systems, bow-tie (BT) analysis is becoming a popular technique as it represents an accident scenario from causes to effects. However, the BT application in the dynamic safety analysis is limited due to the static nature of its components, i.e. fault tree and event tree. It is therefore difficult in BT to take accident precursors into account to update the probability of events and the consequent risk. Also, BT is unable to represent conditional dependency. Event dependency is common among primary events and safety barriers. The current paper illustrates how Bayesian network (BN) helps to overcome these limitations. It has also been shown that BN can be used in dynamic safety analysis of a wide range of accident scenarios due to its flexible structure. This paper also introduces the application of probability adapting in dynamic safety analysis rather than probability updating. A case study from the U.S. Chemical Safety Board has been used to illustrate the application of both BT and BN techniques, with a comparison of the results from each technique.     

Cost-based fire risk assessment in natural gas industry by means of fuzzy FTA and ETA

Fire is the most prevalent accident in natural gas facilities. In order to assess the risk of fire in a gas processing plant, a fault tree analysis (FTA) and event tree analysis (ETA) has been developed in this paper. By utilizing FTA and ETA, the paths leading to an outcome event would be visually demonstrated. The framework was applied to a case study of processing plant in South Pars gas complex. All major underlying causes of fire accident in a gas processing facility determined through a process hazard analysis (PHA). Fuzzy logic has been employed to derive likelihood of basic events in FTA from uncertain opinion of experts. The outcome events in event tree has been simulated by computer model to evaluate their severity. In the proposed methodology the calculated risk has the unit of cost per year which allows the decision makers to discern the benefit of their investment in safety measures and risk mitigation.     

基于JSA-BN的水上提管维修作业风险分析

为保障海底油气管道维修作业安全,提出1种基于JSA-BN的作业风险分析方法。采用JSA方法辨识分析水上提管维修作业过程中潜在的风险因素,得出不同作业步骤的风险等级;建立水上提管维修作业贝叶斯网络模型,计算出各作业环节的成功概率;依托贝叶斯网络的逆向推理及敏感性分析能力,实现水上提管维修作业风险薄弱点的定量预测和评估。研究结果表明:提出的基于JSA-BN的作业风险分析方法可应用于近岸海底管道应急维修作业风险分析;在整个水上提管维修作业活动中,提管作业和切割破损管道作业为关键作业环节,提升过程中碰撞、掉落事件为薄弱风险因素。     

基于STPA和模糊BN的装配式建筑吊装施工安全风险分析*

为有效评估装配式建筑吊装施工中的安全风险状态,识别关键风险因素,运用系统理论过程分析方法(STPA)构建吊装施工过程中的控制反馈结构,识别导致危险的不安全控制行为,确定不安全控制行为的致因因素;基于风险因素间的关联关系构建贝叶斯网络（BN）模型,推理计算装配式建筑吊装施工安全风险状态概率,并结合反向诊断推理分析影响安全事故的风险因素;通过敏感性分析,识别装配式建筑吊装施工安全中的关键风险因素。结果表明:装配式建筑吊装施工安全风险处于低风险状态;起重机械超负荷运行、现场安全管理不到位和吊索吊具存在缺陷等因素是影响装配式建筑吊装施工安全风险的关键风险因素。     

基于FMECA与模糊FTA的余热锅炉安全分析

为了保证余热锅炉安全运行,预防爆炸事故发生,利用FMECA方法和模糊FTA方法,研究余热锅炉事故致因。通过对余热锅炉潜在危险因素的分析辨别,探讨设备故障类型、原因及相应处理方法,引入模糊FTA对余热锅炉爆炸事故定性和定量分析,进而构建了基于FMECA与模糊FTA的余热锅炉安全分析框架,并计算得出事故发生的模糊概率以及对基本事件的敏感性分析。研究表明,余热锅炉系统的可靠度大约为96.92%,未按规定排污,报警器失灵,安全阀压力连接管堵塞及除氧器不合格事件对顶事件发生概率的影响最大,从而为该系统的安全决策提供支持。     

An integrated EDIB model for probabilistic risk analysis of natural gas pipeline leakage accidents

Natural gas pipeline construction is developing rapidly worldwide to meet the needs of international and domestic energy transportation. Meanwhile, leakage accidents occur to natural gas pipelines frequently due to mechanical failure, personal operation errors, etc., and induce huge economic property loss, environmental damages, and even casualties. However, few models have been developed to describe the evolution process of natural gas pipeline leakage accidents (NGPLA) and assess their corresponding consequences and influencing factors quantitatively. Therefore, this study aims to propose a comprehensive risk analysis model, named EDIB (ET-DEMATEL-ISM-BN) model, which can be employed to analyze the accident evolution process of NGPLA and conduct probabilistic risk assessments of NGPLA with the consideration of multiple influencing factors. In the proposed integrated model, event tree analysis (ET) is employed to analyze the evolution process of NGPLA before the influencing factors of accident evolution can be identified with the help of accident reports. Then, the combination of DEMATEL (Decision-making Trial and Evaluation Laboratory) and ISM (Interpretative Structural Modeling) is used to determine the relationship among accident evolution events of NGPLA and obtain a hierarchical network, which can be employed to support the construction of a Bayesian network (BN) model. The prior conditional probabilities of the BN model were determined based on the data analysis of 773 accident reports or expert judgment with the help of the Dempster-Shafer evidence theory. Finally, the developed BN model was used to conduct accident evolution scenario analysis and influencing factor sensitivity analysis with respect to secondary accidents (fire, vapor cloud explosion, and asphyxia or poisoning). The results show that ignition is the most critical influencing factor leading to secondary accidents. The occurrence time and occurrence location of NGPLA mainly affect the efficiency of emergency response and further influence the accident consequence. Meanwhile, the weight ranking of economic loss, environmental influence, and casualties on social influence is determined with respect to NGPLAs.     

A methodology to model causal relationships on offshore safety assessment focusing on human and organizational factors

INTRODUCTION: Focusing on people and organizations, this paper aims to contribute to offshore safety assessment by proposing a methodology to model causal relationships. METHOD: The methodology is proposed in a general sense that it will be capable of accommodating modeling of multiple risk factors considered in offshore operations and will have the ability to deal with different types of data that may come from different resources. Reason's "Swiss cheese" model is used to form a generic offshore safety assessment framework, and Bayesian Network (BN) is tailored to fit into the framework to construct a causal relationship model. The proposed framework uses a five-level-structure model to address latent failures within the causal sequence of events. The five levels include Root causes level, Trigger events level, Incidents level, Accidents level, and Consequences level. To analyze and model a specified offshore installation safety, a BN model was established following the guideline of the proposed five-level framework. A range of events was specified, and the related prior and conditional probabilities regarding the BN model were assigned based on the inherent characteristics of each event. RESULTS: This paper shows that Reason's "Swiss cheese" model and BN can be jointly used in offshore safety assessment. On the one hand, the five-level conceptual model is enhanced by BNs that are capable of providing graphical demonstration of inter-relationships as well as calculating numerical values of occurrence likelihood for each failure event. Bayesian inference mechanism also makes it possible to monitor how a safety situation changes when information flow travel forwards and backwards within the networks. On the other hand, BN modeling relies heavily on experts' personal experiences and is therefore highly domain specific. IMPACT ON INDUSTRY: "Swiss cheese" model is such a theoretic framework that it is based on solid behavioral theory and therefore can be used to provide industry with a roadmap for BN modeling and implications. A case study of the collision risk between a Floating Production, Storage and Offloading (FPSO) unit and authorized vessels caused by human and organizational factors (HOFs) during operations is used to illustrate an industrial application of the proposed methodology.     

基于贝叶斯网络的养老院火灾风险评估方法研究

为预防养老院火灾事故,结合事故树法(FTA)和贝叶斯网络法(BN),建立了一套养老院火灾风险定量评估模型。首先,采用事故树法建立潜在的养老院火灾事故场景;其次,考虑到养老院火灾事故场景中不确定因素的影响,将事故树模型转化为贝叶斯网络模型,并结合有人员伤亡的养老院火灾事故发生发展实际优化模型;最后,以某市养老院为例,结合调研、文献及统计数据确定先验概率及条件概率,并用GENIE 2.0软件实现贝叶斯图形化,分析验证该模型逻辑可行性。结果表明:通过该模型和方法,不仅可以预测养老院火灾事故中各场景发生发展概率,还能对各风险因素敏感度和最大致因链进行分析,提高了风险因素辨识和评价的准确性,可以为养老院火灾风险分析和防控提供参考。     

Conceptual compression discussion on a multi-linear (FTA) and systematic (FRAM) method in an offshore operation’s accident modeling

Risk assessment can be classified into two broad categories: traditional and modern. This paper is aimed at contrasting the functional resonance analysis method (FRAM) as a modern approach with the fault tree analysis (FTA) as a traditional method, regarding assessing the risks of a complex system. Applied methodology by which the risk assessment is carried out, is presented in each approach. Also, FRAM network is executed with regard to nonlinear interaction of human and organizational levels to assess the safety of technological systems. The methodology is implemented for lifting structures deep offshore. The main finding of this paper is that the combined application of FTA and FRAM during risk assessment, could provide complementary perspectives and may contribute to a more comprehensive understanding of an incident. Finally, it is shown that coupling a FRAM network with a suitable quantitative method will result in a plausible outcome for a predefined accident scenario.     

隧洞施工通风系统事故树分析

在采矿、铁路、公路及水利水电工程中，常常采用长距离隧洞或隧道来穿越高山。而隧洞的施工以其施工技术复杂、难度大、风险高，经常成为控制工程工期的主要环节，隧洞施工中的通风换气系统，关系到施工能否顺利进行和施工作业人员的人身安全，根据隧洞施工通风系统的运行特点，采用安全系统分析中的事故树（FTA）方法，对隧洞施工中通风系统的安全性进行定性分析，找出影响通风安全的主要因素，并提出了通风安全管理对策，可以保证施工作业的顺利进行和人身安全，提高整个施工作业的安全度。     

Safety evaluation of leak in a storage tank using fault tree analysis and risk matrix analysis

The work presented in this paper used a quantitative analysis of relevant risks through the development of fault tree analysis and risk analysis methods to aid real time risk prediction and safety evaluation of leak in a storage tank. Criticality of risk elements and their attributes can be used with real time data to predict potential failures likely to occur. As an example, a risk matrix was used to rank risk of events that could lead to a leak in a storage tank and to make decisions on risks to be allowed based on past statistical data. An intelligent system that recognizes increasing level(s) and draws awareness to the possibility of additional increase before unsafe levels are attained was used to analyse and make critical decisions. After a visual depiction of relationships between hazards and controls had been actualized, dynamic risk modelling was used to quantify the effect controls can potentially have on hazards by applying historical and real-time data into a probabilistic model. The output of a dynamic risk model is near real-time quantitative predictions of risk likelihood. Results from the risk matrix analysis method mixed with RTD and FTA were analyzed, evaluated, and compared.     

原油集输联合站故障树分析研究

采用故障树分析法对原油集输联合站生产工艺流程和危险危害因素进行分析,确定原油集输联合站的故障树因素表,以该站故障为顶上事件,以火灾爆炸、介质泄漏、其他危险作为故障树的中间事件,建立联合站故障树。通过定性定量分析,求取联合站故障树的最小割集为77组,进而确定故障树顶事件的事故发生概率为5.68×10-3和底事件结构重要度,得出影响集输联合站安全性的重要因素为通风不良、储罐密封不良、液体腐蚀、盘管穿孔和人员误操作等。因而提出加强原油集输联合站安全监察和监控措施,及时地发现和处理故障,以提高联合站运行安全可靠性和生产效率。     

废弃火药在工业炸药中的再利用研究进展

介绍了废弃发射药及固体推进剂在工业炸药中的资源化利用技术,概述了含火药的粉状炸药、浆状炸药、乳化炸药、铵油炸药及灌注型炸药的爆轰性能,分析了各类炸药的工艺生产、使用及安全环保等特点。粉碎后的火药颗粒(Φ≤5 mm)可用于制备粉状炸药,也可利用现有的工业炸药生产工艺,将火药作为敏化剂加入浆状炸药、乳化炸药/乳化基质中,或将大颗粒火药直接与铵油炸药混合。这些方法工艺简单,且火药的加入有利于提高炸药的爆轰性能。尤其是含火药颗粒的灌注炸药生产工艺更简单、安全性更高,避免了火药粉碎工艺,废弃火药的再利用率高,而且炸药的爆轰性能优良,爆速大于6000 m/s,用作震源药柱或露天炸药等具有良好的应用前景。国内已成功地将废弃发射药再利用于工业炸药中,取得了良好的效益。借鉴国内外的研究成果,结合工业炸药的发展趋势,目前应重点进行废弃复合固体推进剂的应用研究。     

基于飞行剖面的航空器试飞活动空管风险研究

为明确空中交通管理风险对航空器适航试飞活动不安全事件的影响,首先,依据航空器试飞科目绘制相应飞行剖面;其次,基于试飞活动飞行剖面,分析管制单位试飞保障流程,提取管制运行风险对试飞活动的影响因素;采用事故树分析法(FTA)分析事故发展过程,将事件和逻辑关系映射至贝叶斯网络(BN),依据国内外民航空管不安全事件分类统计结果...     

基于前导事件和贝叶斯网络的储罐溢油动态风险评价

部分高风险危化品企业搬迁改造困难重重,为控制风险、保护周围人民生命和财产安全,有必要建立动态风险评价系统,对事故发生概率进行监控和预测。采用贝叶斯网络对事故发生概率进行定量分析。先在利用蝴蝶结模型辨识事故原因和后果的基础上,将其转化为贝叶斯网络模型;再导入"前导事件"信息和先验概率推导后验事故发生概率,量化分析事故发生随时间的变化概率;最后,以储罐溢流场景为例进行动态风险计算,结果表明,随化工装置生产时间和"前导事件"增长,元件失效概率和事故风险呈显著增长趋势。因此建议企业应重视"前导事件"并采取措施减少"前导事件",如优化检维修方案、及时更换关键部件、进行全面的事故调查等。     

Safety assessment of natural gas storage tank using similarity aggregation method based fuzzy fault tree analysis (SAM-FFTA) approach

Fault tree analysis (FTA) is an important method to analyze the failure causes of engineering systems and evaluate their safety and reliability. In practical application, the probabilities of bottom events in FTA are usually estimated according to the opinions of experts or engineers because it is difficult to obtain sufficient probability data of bottom events in fault tree. However, in many cases, there are many experts with different opinions or different forms of opinions. How to reasonably aggregate expert opinions is a challenge for the engineering application of fault tree method. In this study, a fuzzy fault tree analysis approach based on similarity aggregation method (SAM-FFTA) has been proposed. This method combines SAM with fuzzy set theory and can handled comprehensively diverse forms of opinions of different experts to obtain the probabilities of bottom events in fault tree. Finally, for verifying the applicability and flexibility of the proposed method, a natural gas spherical storage tank with a volume of 10,000 m³ was analyzed, and the importance of each bottom event was determined. The results show that flame, lightning spark, electrostatic spark, impact spark, mechanical breakdown and deformation/breakage have the most significant influence on the explosion of the natural gas spherical storage tank.     

效益型安全管理在石油企业主营业务中的应用——以钻井地质设计的事故树(FTA)分析为例

为了实现石油企业的效益与安全兼顾,引入安全管理的事故树(FTA)分析法查找主要风险点,利用计算机软件模拟预测主营业务的生产流程,对每个技术环节定量计算、精准投入,规避并控制风险点,在收获并保护油层的同时保证安全生产,从而实现效益与安全兼顾;通过实例表明,该方法在企业的安全管理中是可行的。     

基于FTA-Petri网的地铁火灾事故安全性研究

鉴于城市轨道交通安全的复杂性及重要性,应用FTA-Petri综合分析方法对城市轨道交通系统安全性进行分析并构建轨道交通系统火灾事故安全性模型。该模型具有FTA与Petri网方法的优点。在利用传统的FTA方法深入分析火灾事故原因的基础上,选择典型的火灾事故成因,利用Petri网方法动态模拟火灾事故发生的过程;借鉴已有的概率计算方法对所建立的火灾Petri网模型进行定量求解分析;最后,针对分析结果提出可行性方案。提出将FTA-Petri综合分析方法应用到城市轨道交通安全领域,在地铁火灾安全性定量分析方面作出了探索性的研究。     

Dynamic risk analysis of offloading process in floating liquefied natural gas (FLNG) platform using Bayesian Network

The growing demand for natural gas has pushed oil and gas exploration to more isolated and previously untapped regions around the world where construction of LNG processing plants is not always a viable option. The development of FLNG will allow floating plants to be positioned in remote offshore areas and subsequently produce, liquefy, store and offload LNG in the one position. The offloading process from an FLNG platform to a gas tanker can be a high risk operation. It consists of LNG being transferred, in hostile environments, through loading arms or flexible cryogenic hoses into a carrier which then transports the LNG to onshore facilities. During the carrier's offloading process at onshore terminals, it again involves risk that may result in an accident such as collision, leakage and/or grounding. It is therefore critical to assess and monitor all risks associated with the offloading operation. This study is aimed at developing a novel methodology using Bayesian Network (BN) to conduct the dynamic safety analysis for the offloading process of an LNG carrier. It investigates different risk factors associated with LNG offloading procedures in order to predict the probability of undesirable accidents. Dynamic failure assessment using Bayesian theory can estimate the likelihood of the occurrence of an event. It can also estimate the failure probability of the safety system and thereby develop a dynamic failure assessment tool for the offloading process at a particular FLNG plant. The main objectives of this paper are: to understand the LNG offloading process, to identify hazardous events during offloading operation, and to perform failure analysis (modelling) of critical accidents and/or events. Most importantly, it is to evaluate and compare risks. A sensitivity analysis has been performed to validate the risk models and to study the behaviour of the most influential factors. The results have indicated that collision is the most probable accident to occur during the offloading process of an LNG carrier at berth, which may have catastrophic consequences.