Semi-Quantitative Risk Assessment Matrix for Rotating Equipment

2013 ◽  
Vol 845 ◽  
pp. 647-651
Author(s):  
Mohd Amin bin Abd Majid ◽  
Rano Khan Wassan ◽  
Ainul Akmar Mokhtar
Keyword(s):  
Risk Assessment ◽  
Failure Modes ◽  
Oil And Gas ◽  
Guide Vane ◽  
Quantitative Risk Assessment ◽  
Inlet Guide Vane ◽  
Risk Matrix ◽  
Assessment Approach ◽  
Rotating Equipment ◽  
Blade Failure

In petrochemical, power generation, oil and gas industries and in variety of other sectors rotating equipments are in use to fulfill production requirements. Failure of rotating equipment, especially in such industries can result to risk related issues. A well implemented rotating equipment risk assessment strategy is most needed to achieve desired plant availability and efficiency. In this research semi-quantitative risk assessment approach is proposed to evaluate the risk of rotating equipment and categorize their associated failure risks. Borda ranking is adopted to evaluate the risk in order to minimize risk ties which exist in risk matrix. Compressor is taken as case study to show the applicability of the proposed method for rotating equipment. It was observed that risks of selected failure modes of gas turbine compressor fall in the categories of serious and medium levels based on risk matrix. Rotor bend distortion, blade failure or inlet guide vane failures needed more attention for treatment based on Borda ranking.

Risk Screening as Input for Risk Assessment of Rotating Equipment

2015 ◽  
Vol 761 ◽  
pp. 333-338
Author(s):  
Rano Khan Wassan ◽  
Abd Majid Mohd Amin
Keyword(s):  
Power Generation ◽  
Risk Assessment ◽  
Combustion Chamber ◽  
Failure Modes ◽  
Assessment Model ◽  
Quantitative Risk Assessment ◽  
Risk Screening ◽  
Effect Analysis ◽  
Strategy Planning ◽  
Rotating Equipment

Risk assessment of complex rotating equipment is costly and time consuming process. Due to the reason, only critical equipment should be considered for detailed risk assessment. In this study, a semi-quantitative risk assessment model was developed to assess the risk of rotating equipment. The model consists of four main parts, initial risk screening, risk assessment, Failure Mode and Effect Analysis (FMEA) and maintenance strategy planning based on reliability concept. The model was used to assess risk of rotating equipment of power generation unit. Initial risk screening indicated compressor, combustion chamber, turbine and lube oil system of the power generation system as critical equipment under serious risks. Risk assessment using Borda ranking minimized the risk ties and showed compressor, combustion chamber and turbine were more critical as compared to lube oil system. Failure modes were identified using FMEA, 68% of the downtime was due to compressor, combustion chamber and turbine failure modes. Only 32% of the downtime was due to lube oil subsystems failure modes. Maintenance interval for compressor, combustion chamber and turbine was calculated 2 months and 5 months for lube oil system to reduce risk.

Applying the Quantitative Risk Assessment (QRA) to Improve Safety Management of Oil and Gas Pipeline Stations in China

2012 ◽  
Author(s):  
Wenxing Feng ◽  
Xiaoqiang Xiang ◽  
Guangming Jia ◽  
Lianshuang Dai ◽  
Yulei Gu ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Environmental Protection ◽  
Oil And Gas ◽  
Hazard Identification ◽  
Gas Pipeline ◽  
Industrial Safety ◽  
Quantitative Risk Assessment ◽  
Chinese Government ◽  
Land Resource ◽  
Oil Pipeline

The oil and gas pipeline companies in China are facing unprecedented opportunities and challenges because of China’s increasing demand for oil and gas energy that is attributed to rapid economic and social development. Limitation of land resource and the fast urbanization lead to a determinate result that many pipelines have to go through or be adjacent to highly populated areas such as cities or towns. The increasing Chinese government regulation, and public concerns about industrial safety and environmental protection push the pipeline companies to enhance the safety, health and environmental protection management. In recent years, PetroChina Pipeline Company (PPC) pays a lot of attention and effort to improve employees and public safety around the pipeline facilities. A comprehensive, integrated HSE management system is continuously improved and effectively implemented in PPC. PPC conducts hazard identification, risk assessment, risk control and mitigation, risk monitoring. For the oil and gas stations in highly populated area or with numerous employees, PPC carries out quantitative risk assessment (QRA) to evaluate and manage the population risk. To make the assessment, “Guidelines for quantitative risk assessments” (purple book) published by Committee for the Prevention of Disasters of Netherlands is used along with a software package. The basic principles, process, and methods of QRA technology are introduced in this article. The process is to identify the station hazards, determinate the failure scenarios of the facilities, estimate the possibilities of leakage failures, calculate the consequences of failures and damages to population, demonstrate the individual risk and social risk, and evaluate whether the risk is acceptable. The process may involve the mathematical modeling of fluid and gas spill, dispersion, fire and explosion. One QRA case in an oil pipeline station is described in this article to illustrate the application process and discuss several key issues in the assessment. Using QRA technique, about 20 stations have been evaluated in PPC. On the basis of the results, managers have taken prevention and mitigation plans to control the risk. QRAs in the pipeline station can provide a quantitative basis and valuable reference for the company’s decision-making and land use planning. Also, QRA can play a role to make a better relationship between the pipeline companies and the local regulator and public. Finally, this article delivers limitations of QRA in Chinese pipeline stations and discusses issues of the solutions.

Uncertainty Analysis in Quantitative Risk Assessment

1996 ◽  
Vol 118 (1) ◽  
pp. 121-124 ◽  
Author(s):  
S. Quin ◽  
G. E. O. Widera
Keyword(s):  
Risk Assessment ◽  
Uncertainty Analysis ◽  
Set Theory ◽  
Fuzzy Set ◽  
Fuzzy Set Theory ◽  
Failure Modes ◽  
The Other ◽  
Quantitative Risk Assessment ◽  
Engineering Practice ◽  
Criticality Analysis

Of the quantitative approaches applied to inservice inspection, failure modes, effects,criticality analysis (FMECA) methodology is recommended. FMECA can provide a straightforward illustration of how risk can be used to prioritize components for inspection (ASME, 1991). But, at present, it has two limitations. One is that it cannot be used in the situation where components have multiple failure modes. The other is that it cannot be used in the situation where the uncertainties in the data of components have nonuniform distributions. In engineering practice, these two situations exist in many cases. In this paper, two methods based on fuzzy set theory are presented to treat these problems. The methods proposed here can be considered as a supplement to FMECA, thus extending its range of applicability.

scholarly journals Domain-specific risk assessment using integrated simulation: A case study of an onshore wind project

2021 ◽  
Author(s):  
Emad Mohamed ◽  
Nima Gerami Seresht ◽  
Stephen Hague ◽  
Adam Chehouri ◽  
Simaan M. AbouRizk
Keyword(s):  
Risk Assessment ◽  
Wind Farm ◽  
Critical Path ◽  
Quantitative Risk Assessment ◽  
Integrated Simulation ◽  
Domain Specific ◽  
Risk Assessment Models ◽  
First Case ◽  
Assessment Approach

Although many quantitative risk assessment models have been proposed in literature, their use in construction practice remain limited due to a lack of domain-specific models, tools, and application examples. This is especially true in wind farm construction, where the state-of-the-art integrated Monte Carlo simulation and critical path method (MCS-CPM) risk assessment approach has yet to be demonstrated. The present case study is the first reported application of the MCS-CPM method for risk assessment in wind farm construction and is the first case study to consider correlations between cost and schedule impacts of risk factors using copulas. MCS-CPM provided reasonable risk assessment results for a wind farm project, and its use in practice is recommended. Aimed at facilitating the practical application of quantitative risk assessment methods, this case study provides a much-needed analytical generalization of MCS-CPM, offering application examples, discussion of expected results, and recommendations to wind farm construction practitioners.

The Assignment of SIL Targets to Overpressure Protection in Reactive Systems

2004 ◽  
Author(s):  
Kimberly A. Dejmek ◽  
Ken A. Wehrman
Keyword(s):  
Risk Assessment ◽  
Risk Reduction ◽  
Quantitative Assessment ◽  
Historical Data ◽  
Reactive Systems ◽  
Warning Signs ◽  
The Other ◽  
Quantitative Risk Assessment ◽  
Risk Matrix ◽  
Performance Targets

The assignment of performance targets, or target Safety Integrity Levels (SILs), is a critical step in the application of the Safety Instrumented System (SIS) standards, i.e., ANSI/ISA S84.0.01-1996, IEC 61508 and IEC61511. Although the SIL is a key concept in the implementation of the standards, the development and application of a method for determining the target SIL has been left to the owner/operator. The standards do, however, provide guidance on this topic and present a number of techniques that can be considered, including risk matrix, risk graph, and Layers of Protection Analysis (LOPA). Generally, the methods for SIL assignment are qualitative or semi-quantitative risk assessment methods that are based upon the judgments of an assignment team. In most cases the methods based on expert opinion and limited historical data are adequate. However, in the case of overpressure protection for reactive systems, the number and complexity of the scenarios often overwhelms these simplified approaches. There are warning signs that can aid in the identification of cases where the simplified methods may break down and provide non-conservative results. In cases such as this, a quantitative assessment should be conducted to evaluate the likelihood of SIF demands, the risk reduction supplied by the other protection layers, with the aim of determining the risk reduction required from the instrumented overpressure protection system.

An Experimental Study of the Slip Factor in a Wet Gas Centrifugal Compressor With IGV

2017 ◽  
Author(s):  
Levi André B. Vigdal ◽  
Lars E. Bakken
Keyword(s):  
Experimental Study ◽  
Gas Flow ◽  
Oil And Gas ◽  
Guide Vane ◽  
Flow Characteristics ◽  
Inlet Guide Vane ◽  
Liquid Content ◽  
Slip Factor ◽  
Wet Gas ◽  
Inlet Swirl

The introduction of wet gas compression provides the opportunity for future cost-effective production of oil and gas. A wet gas compressor consists of a robust unit able to increase the pressure of untreated natural gas. This permits longer transport of hydrocarbons without topside facilities if installed at the well head. Obvious benefits include prolonging the life of existing wells and the possibility of exploiting smaller hydrocarbon sources otherwise considered non-commercial. Successful development of robust wet gas compressors requires further understanding of the phenomena which occur when liquid is present in the gas stream. Understanding the way the presence of liquid affects the velocity triangle and slip factor is essential for the design of wet gas compressors and for comprehending their response to varying levels of liquid content in the inlet stream. An experimental study has been performed with various levels of liquid fractions and inlet swirl angles. Impeller-exit velocity components and shift in slip factors are presented within the experimental test boundary. A shift in velocity components and slip factor is experienced with increasing liquid content and inlet guide vane (IGV) setting angle. Consequently, existing slip factor correlations not utilizing inlet flow characteristics are not valid for wet gas flow or with impeller inlet swirl.

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