A framework for the establishment of organizational risk indicators

Organizational risk indicators are proposed as a tool for risk control during operation of offshore installations, as a complement to QRA-based indicators. An organizational factor framework is developed based on a review of existing organizational factor frameworks, research on safety performance indicators, and previous work on QRA-based indicators. The results comprise a qualitative organizational model, proposed organizational risk indicators, and a quantification methodology for assessing the impact of the organization on risk. The risk indicators, when validated, will aid in a frequent control of the risk in the periods between the updating of the quantitative risk assessments.     

Barrier and operational risk analysis of hydrocarbon releases (BORA-Release). Part I. Method description

Investigations of major accidents show that technical, human, operational, as well as organisational factors influence the accident sequences. In spite of these facts, quantitative risk analyses of offshore oil and gas production platforms have focused on technical safety systems. This paper presents a method (called BORA-Release) for qualitative and quantitative risk analysis of the platform specific hydrocarbon release frequency. By using BORA-Release it is possible to analyse the effect of safety barriers introduced to prevent hydrocarbon releases, and how platform specific conditions of technical, human, operational, and organisational risk influencing factors influence the barrier performance. BORA-Release comprises the following main steps: (1) development of a basic risk model including release scenarios, (2) modelling the performance of safety barriers, (3) assignment of industry average probabilities/frequencies and risk quantification based on these probabilities/frequencies, (4) development of risk influence diagrams, (5) scoring of risk influencing factors, (6) weighting of risk influencing factors, (7) adjustment of industry average probabilities/frequencies, and (8) recalculation of the risk in order to determine the platform specific risk related to hydrocarbon release. The various steps in BORA-Release are presented and discussed. Part II of the paper presents results from a case study where BORA-Release is applied.     

Major hazard risk indicators for monitoring of trends in the Norwegian offshore petroleum sector

The Petroleum Safety Authority Norway (PSA, formerly Norwegian Petroleum Directorate) took in 1999 the initiative to develop a method in order to assess trends and status for the risk levels in the Norwegian offshore petroleum industry. A method was developed, and a pilot study report was issued in April 2001, covering the period 1996–2000. Annual updates have been performed since then, and the latest report covers the period 1996–2004. The statistical approach is based on recording occurrence of near misses and relevant incidents, performance of barriers and results from risk assessments. Of similar importance is an evaluation of safety culture, motivation, communication and perceived risk. This is covered through the use of social science methods, such as questionnaire surveys and a number of interviews, audit and inspection reports as well as accident and incident investigations. There are also indicators for occupational accidents and occupational illness/-physical working environment factors.The focus is on the major hazard risk components for personnel staying on the offshore installations. An overview of the indicators used to illustrate these risk aspects is presented, followed by a discussion of the analytical approach used for these indicators. Results from the risk assessment for the Norwegian Continental Shelf in the period 1996–2004 are used throughout for illustration, and discussion of challenges.     

Risk-based process safety assessment and control measures design for offshore process facilities

Process operation is the most hazardous activity next to the transportation and drilling operation on an offshore oil and gas (OOG) platform. Past experiences of onshore and offshore oil and gas activities have revealed that a small mis-happening in the process operation might escalate to a catastrophe. This is of especial concern in the OOG platform due to the limited space and compact geometry of the process area, less ventilation, and difficult escape routes. On an OOG platform, each extra control measure, which is implemented, not only occupies space on the platform and increases congestion but also adds extra load to the platform. Eventualities in the OOG platform process operation can be avoided through incorporating the appropriate control measures at the early design stage. In this paper, the authors describe a methodology for risk-based process safety decision making for OOG activities. The methodology is applied to various offshore process units, that is, the compressor, separators, flash drum and driers of an OOG platform. Based on the risk potential, appropriate safety measures are designed for each unit. This paper also illustrates that implementation of the designed safety measures reduces the high Fatal accident rate (FAR) values to an acceptable level.     

海洋平台结构参数识别和损伤诊断技术的研究进展 第十三届全国结构工程学术会议特邀报告

本文综述了海洋平台结构模态参数识别和损伤诊断技术的发展状况,对基于动力测试的损伤诊断方法进行了归纳评价,着重分析了该技术在实际应用中困难,介绍了近年来海洋平台结构模态参数识别和损伤诊断最新研究进展。最后,讨论了海洋结构损伤诊断领域未来发展的关键问题,对该技术未来发展前景进行展望,并且提出亟待解决的难题。     

On the use of risk acceptance criteria in the offshore oil and gas industry

Risk acceptance criteria, as upper limits of acceptable risks, have been used for offshore activities on the Norwegian Continental Shelf for more than 20 years. The common thinking has been that risk analyses and assessments cannot be conducted in a meaningful way without the use of such criteria. The ALARP principle also applies, but the risk acceptance criteria have played a more active role in the assessment processes than seen for example in the UK. Recently there has, however, been a discussion about the suitability of risk acceptance criteria to assess and control risks. The purpose of this paper is to contribute to this discussion by presenting and discussing a risk analysis regime that is not based on the use of risk acceptance criteria at all. We believe that we can do better if cost-effectiveness (in a wide sense) is the ruling thinking rather than adoption of pre-defined risk acceptance limits. This means a closer resemblance with the ALARP principle as adopted in the UK and other countries, but is not a direct application of this practice. Also the building blocks of the common way of applying the ALARP principle are reviewed. The Norwegian offshore oil and gas industry is the starting point, but the discussion is to large extent general.     

环境变化下基于AR模型系数和协整的海洋平台结构损伤识别

结构损伤引起的损伤特征参数的变化往往被环境因素（温度、质量）变化引起的损伤特征参数的变化所掩盖,从而导致基于振动的损伤识别方法失效。该文利用时间序列中的AR模型系数和计量经济学中的协整进行环境因素（温度、质量）影响下的海洋平台结构损伤识别研究。首先利用AR模型对实测的加速度响应信号进行拟合,选择第一阶AR系数为协整变量,然后对不同节点的协整变量进行协整,将协整残差作为损伤指标,最后通过X-bar控制图进行结构的损伤识别。海洋平台结构的数值模拟和振动台模型试验结果验证了该方法的有效性。     

Mining and Tracking Massive Text Data: Classification,Construction of Tracking Statistics,and Inference Under Misclassification

This article presents a comprehensive data-mining procedure for exploring large freestyle text datasets to discover useful features and develop suitable tracking statistics (often referred to as performance measures or risk indicators). The procedure includes text classification, construction of tracking statistics, inference under error measurements, and risk analysis. Some specific text analysis methodologies and tracking statistics are discussed. Several approaches for incorporating misclassified data or error measurements into the inference for tracking statistics are proposed and evaluated. Finally, as an illustrative example, the proposed data-mining procedure is applied to analyzing an aviation safety report repository to show its utility in aviation risk management or general decision-support systems.     

A decision framework for risk management, with application to the offshore oil and gas industry

In this paper we present and discuss a decision framework for risk management. The framework comprises the basic elements: problem definition (challenges, goals and alternatives), stakeholders, concerns that affect the consequence analyses and the value judgments related to these consequences and analyses (frame conditions and constraints), identification of which consequence analyses to execute and the execution of these, managerial review and judgement, and the decision. The framework has novel aspects on the way of classifying the decision situations and characterising risks. The classification is based on the two dimensions, expected consequences, and uncertainties. Our starting point is the offshore oil and gas industry, but our framework and discussion is to a large extent general and could also be applied in other areas. An example is outlined to illustrate the use of the framework.     

Use of QRA for decision support in the design of an offshore oil production installation

QRA is today widely used as a tool for decision support in the offshore industry. Its use has gradually changed from a prescribed analysis for verification purposes to a tool being actively used in an integrated mode. The paper describes its use in the design of a modern offshore platform. The paper addresses work methodology, selection of tools and data, organisation of QRA with other activities. Specific examples are given.     

ARAMIS project: a more explicit demonstration of risk control through the use of bow-tie diagrams and the evaluation of safety barrier performance

Over the last two decades a growing interest for risk analysis has been noted in the industries. The ARAMIS project has defined a methodology for risk assessment. This methodology has been built to help the industrialist to demonstrate that they have a sufficient risk control on their site.

Risk analysis consists first in the identification of all the major accidents, assuming that safety functions in place are inefficient. This step of identification of the major accidents uses bow–tie diagrams. Secondly, the safety barriers really implemented on the site are taken into account. The barriers are identified on the bow–ties. An evaluation of their performance (response time, efficiency, and level of confidence) is performed to validate that they are relevant for the expected safety function. At last, the evaluation of their probability of failure enables to assess the frequency of occurrence of the accident. The demonstration of the risk control based on a couple gravity/frequency of occurrence is also possible for all the accident scenarios.

During the risk analysis, a practical tool called risk graph is used to assess if the number and the reliability of the safety functions for a given cause are sufficient to reach a good risk control.     

Risk based maintenance optimization: foundational issues

Lately there has been an increasing focus on risk based maintenance optimization in the offshore industry prompted by new functional regulations on risk. In this paper we present alternative probabilistic frameworks for this optimization, using a Bayesian approach. Some key features of the frameworks are discussed, including uncertainty treatment and type of performance measures to be used.     

Stochastic modelling for the analysis of blowout risk in exploration drilling

This article discusses the theoretical basis and the general framework related to stochastic blowout modelling in an offshore risk management context. The general scope is put forward by the Norwegian Petroleum Directorate (NPD) and the operating companies' need for an adequate decision making tool that permits studies of the effects of implemented risk reducing measures based on local conditions. Previous work and today's practices regarding stochastic modelling for the analysis of blowout risk are reviewed and discussed. Moreover, a different and perhaps more thorough approach to blowout risk modelling in exploration drilling is suggested that is based upon physical causal mechanisms and expert judgements combined with hard data rather than world wide blowout statistics.     

Professional culture and risk perception: Coping with danger on board small fishing boats and offshore service vessels

This paper discusses the relationships between subjective risk perception and individuals’ adaptation to high-risk working conditions. It is based on a study carried out among personnel on offshore service vessels in the North Sea and Norwegian fishermen. Risk perception, fatality rates and the discrepancy between subjective risk perception and formal risk levels are compared. The results of these comparisons are discussed by using the concept of culture, and indicate that a correlation between formal risk estimation and subjective perception does not necessarily exist. In fact, subjective risk perception may be seen as a reflection of interactional conventions developed among employees dealing with their working conditions, more than as a reflection of the formal estimated risk level.     

A methodology for developing product platforms in the specific setting of the housebuilding industry

Platform based strategies have proved to be a successful approach for achieving optimum balances between standardization and variation in many industries. However, application of this concept in the housebuilding industry is relatively new. This article describes a new methodology for developing product platform architectures in the specific setting of the housebuilding industry. This methodology comprises a reference framework describing the basic elements that constitutes a product platform, supported by a protocol for developing product platforms. The applicability of the proposed methodology has been tested at a Dutch housebuilding company. In this study, the methodology demonstrated its added value in determining which modules to standardize and defining a product platform. This article also describes a distinctive method of housing classification that is based on the spatial use of houses. Compared to the traditional classification system based on technical construction elements, the proposed new classification system facilitates a better translation of functional requirements into technical specifications.     

Fire safety assessment and optimal design of passive fire protection for offshore structures

The article presents a unified probabilistic approach to fire safety assessment and optimal design of passive fire protection on offshore topside structures. The methodology was developed by integrating quantitative risk analysis (QRA) techniques with the modem methods of structural system reliability analysis (SRA) and reliability based design optimisation (RBDO). Reliability analysis methodologies are presented for both plated (e.g. fire and blast walls) and skeletal structures (deck framing), which take into account uncertainties in fire and blast loading, thermal and mechanical properties of the steel and insulation. Probability of component and system failure are evaluated using first- and second-order reliability methods (FORM/SORM). The optimisation of passive fire protection is performed such that the total expected cost of the protection system is minimised while satisfying reliability constraints.     

ARAMIS project: a comprehensive methodology for the identification of reference accident scenarios in process industries

In the frame of the Accidental Risk Assessment Methodology for Industries (ARAMIS) project, this paper aims at presenting the work carried out in the part of the project devoted to the definition of accident scenarios. This topic is a key-point in risk assessment and serves as basis for the whole risk quantification.

The first result of the work is the building of a methodology for the identification of major accident hazards (MIMAH), which is carried out with the development of generic fault and event trees based on a typology of equipment and substances. The term “major accidents” must be understood as the worst accidents likely to occur on the equipment, assuming that no safety systems are installed.

A second methodology, called methodology for the identification of reference accident scenarios (MIRAS) takes into account the influence of safety systems on both the frequencies and possible consequences of accidents. This methodology leads to identify more realistic accident scenarios. The reference accident scenarios are chosen with the help of a tool called “risk matrix”, crossing the frequency and the consequences of accidents.

This paper presents both methodologies and an application on an ethylene oxide storage.     

Application of a generic bow-tie based risk analysis framework on risk management of sea ports and offshore terminals

Ports and offshore terminals are critical infrastructure resources and play key roles in the transportation of goods and people. With more than 80 percent of international trade by volume being carried out by sea, ports and offshore terminals are vital for seaborne trade and international commerce. Furthermore in today's uncertain and complex environment there is a need to analyse the participated risk factors in order to prioritise protective measures in these critically logistics infrastructures. As a result of this study is carried out to support the risk assessment phase of the proposed Risk Management (RM) framework used for the purpose of sea ports and offshore terminals operations and management (PTOM). This has been fulfilled by integration of a generic bow-tie based risk analysis framework into the risk assessment phase as a backbone of the phase. For this reason Fault Tree Analysis (FTA) and Event Tree Analysis (ETA) are used to analyse the risk factors associated within the PTOM. This process will eventually help the port professionals and port risk managers to investigate the identified risk factors more in detail. In order to deal with vagueness of the data Fuzzy Set Theory (FST) and possibility approach are used to overcome the disadvantages of the conventional probability based approaches.     

船舶-自升式海洋平台碰撞相似率研究

海洋平台作为海洋能源勘探开发的主要组成部分,是海洋油气探井、钻井、开采的主要作业基地。船舶碰撞致使平台结构损伤破坏一直是威胁海洋平台安全的主要因素之一,开展海洋平台碰撞性能研究,揭示平台结构在碰撞过程中的损伤变形机理,对提升平台安全性具有重要意义。评估平台结构耐撞性能最可靠的方法是实船碰撞试验,然而因其耗资巨大而不易开展。按一定相似关系进行比例模型试验成为现实条件下的首选。本文基于相似第二定理,运用量纲分析法推导船舶-自升式海洋平台碰撞过程中各物理量的相似关系,为平台碰撞模型试验的开展及试验参数的确定提供重要依据。结合有限元仿真技术,以平台典型的T型和K型管节点为研究对象,建立不同缩尺比下的简化碰撞模型,比较验证相似理论的可靠性。研究结果表明,缩尺模型在碰撞冲击载荷下的结构损伤变形、碰撞力和能量吸收等动态响应与实尺度模型结果一致性较好。本文研究成果可以为大型平台结构碰撞模型试验设计提供技术支撑。