IEC 61511—functional safety in the process industry: the prominence of validation and verification in the lifecycle of a safety instrumented system

2015 ◽  
Vol 55 (1) ◽  
pp. 379
Author(s):  
Andrew Derbyshire
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Process Industry ◽  
Functional Safety ◽  
Validation And Verification ◽  
Gas Industry ◽  
Cherry Picking ◽  
The Difference ◽  
Correct Understanding ◽  
Verification Strategy

As the concept of risk management has gathered momentum in the oil and gas industry during the past decade, so to has the adoption of IEC 61511, the internationally recognised standard for functional safety in the process industry. IEC 61511 is a risk-based standard that uses the concept of an electrical/electronic/programmable electronic based control system to implement autonomous means of risk reduction against a pre-defined unwanted hazardous deviation in a process. While IEC 61511 has been in existence for more than a decade, the correct understanding and implementation of the standard to derive an effective demonstrate of compliance is still debatable. The standard follows a cradle-to-grave approach to the lifecycle of any safety instrumented system and, unlike other standards where cherry-picking of the requirements may be carried out, IEC 61511 necessitates a demonstration of compliance to all lifecycle phases and their associated requirements. The author of this peer-reviewed paper is fully aware of how difficult-to-digest the subject is; therefore, this paper on the prominence of validation and verification is presented in a pictorial, unambiguous and easy-to-digest manner while paying particular attention to the requirements defined for validation and verification in the standard. The topic of validation and verification in the overall lifecycle of IEC 61511 will be covered by the following questions: What is the difference between validation and verification in the context of IEC 61511? What is the difference between verification against IEC 61511 and IEC 61508? When should planning for validation and verification happen? When should validation and verification be carried out? What are the implications of not carrying out validation and verification? How does validation and verification fit into the wider context of the IEC 61511 lifecycle? What level of independence is required for validation and verification? The paper will also attempt to provide a practical example of how to implement an effective validation and verification strategy into an overall Functional Safety Plan to give the reader a clearer understanding of the obligations toward demonstrating compliance.

Assessing Low-Constraint Fracture Toughness Test Methods Using Clamped SENT Specimens

2019 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Tom McGaughy
Keyword(s):  
Fracture Toughness ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Test Methods ◽  
Fracture Toughness Test ◽  
Single Edge ◽  
Gas Industry ◽  
End Conditions ◽  
The Difference ◽  
Low Constraint

Abstract The low-constraint fracture toughness can be measured using a single edge-notched tension (SENT) specimen in the clamped-end conditions. The SENT specimen has been used in the oil and gas industry in the strain-based design and the crack assessment for transmission pipelines. Since 2006 when DNV published the first SENT test practice, many investigations have been done, and various SENT test methods were developed, including CANMET and ExxonMobil methods in terms of the J-integral and CTOD. The effort led to the first SENT test standard BS 8571 being published in 2014. However, the experimental evaluation methods remain in developing, and different methods may determine inconsistent results. For this reason, the present paper gives a brief review on SENT fracture testing and assesses the available test methods, including progresses on study of stress intensity factor, geometric eta factors, elastic compliance equation, and constraint m factor as well. The difference between J-converted CTOD and double clip gage measured CTOD is also discussed. On those bases, agreements and challenges in SENT testing are identified. The results provide a direction for further investigation to improve the current SENT test methods.

Explosion risk on offshore and onshore facilities—is there an explosion risk problem or an explosion modelling problem?

2015 ◽  
Vol 55 (1) ◽  
pp. 337
Author(s):  
Ingar Fossan ◽  
Sverre Nodland
Keyword(s):  
Gas Turbines ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Control Measures ◽  
Risk Level ◽  
Gas Industry ◽  
Industry Practice ◽  
Ultimate Outcome ◽  
The Difference ◽  
Explosion Risk

Management of the risk related to the loss of containment of flammable fluid is paramount to ensure safe operations at facilities processing or storing flammable fluids. According to best industry practice, an extensive set of safety functions—including measures that reduce the frequency of initiating events (e.g. leaks) and measures that mitigate consequences in case of ignition—are implemented in design to control the risk. Adopting the risk-based design principles that are commonly enforced in the oil and gas industry, the performance of implemented safety barriers are assessed both qualitatively and quantitatively using different methodologies such as hazard and operability analysis (HAZOP), failure mode and effects analysis (FMEA), and quantitative risk analysis (QRA). The ultimate outcome from the QRA methodology is used to assess the overall risk level as well as to assess dimensioning accidental loads (DALs) for equipment and structures that will ensure a design that is within the tolerable risk level set for the facility. An accurate assessment of DALs resulting from fires and explosion is crucial to manage both the risk and corresponding cost driving factors. The most critical safety barrier in this regard is to minimise leaks and thereafter to prevent ignition of the dispersed flammable fluid. A fundamental safety design principle is to find ways to avoid the occurrence of incidents rather than implement measures that mitigate consequences. This peer-reviewed paper demonstrates the significance of modelling the safety functions that are in place to ensure that the initial leak does not ignite by presenting a case example for different layouts of a conventional jacket installation with gas turbines. It is concluded that the difference between various available ignition models can be more prominent than the uncertainty related to any other model element in the QRA. To uncover potential hazards not reflected by the model and identify optimal control measures, the effect of the ignition model applied should be investigated in detail for installations where the QRA displays a prominent fire and explosion frequency.

scholarly journals Accelerated 2D FWI using the symmetry on inner product spaces

2018 ◽  
Vol 8 (2) ◽  
Author(s):  
Reynaldo Fabian Noriega ◽  
Sergio Alberto Abreo- Carillo ◽  
Ana Beatríz Ramírez- Silva
Keyword(s):  
Execution Time ◽  
High Performance ◽  
Oil And Gas ◽  
Waveform Inversion ◽  
Computational Cost ◽  
Oil And Gas Industry ◽  
Inner Product ◽  
Gas Industry ◽  
Common Technique ◽  
The Difference

Full Waveform Inversion (FWI) is a common technique used in the oil and gas industry due to its capabilities to estimate subsurface characteristics such as material’s density and sound velocity with high resolution. The 2D time domain FWI method involves the modeling of the forward wavefield of the source and the backpropagated field of the difference between the modeled and observed data. Therefore, due to its high computational cost in terms of RAM consumption and execution time, the High Performance Computing (HPC) field is very useful to deal with these problems. There are computational state-of-the-art solutions that allow to increase the execution time such as the parallel programming paradigm that involves the use of multicore processor systems. Furthermore, there are mathematical solutions leveraging on the properties of the algorithm used that make it possible to enhance performance of the method. We propose in this paper a new way to compute the FWI gradient, by taking advantage of an inner product property. Additionally, a computational strategy is combined with this proposal in the inversion scheme, thus improving FWI performance.

On the Difference Between Risk as Seen From the Perspectives of the Analysts and Management

2016 ◽  
Vol 2 (3) ◽  
Author(s):  
Terje Aven
Keyword(s):  
Risk Assessment ◽  
Decision Maker ◽  
Potential Risk ◽  
Oil And Gas ◽  
Background Knowledge ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Risk Sources ◽  
The Difference ◽  
Risk Assessment And Management

In its general form, risk is quantitatively described by analysts by identifying a set of consequences C of an activity and using a measure Q to express the uncertainties related to these consequences. This risk description (C,Q) is based on a background knowledge K, including assumptions on which the (C,Q) assessment was found. The purpose of the present paper is to draw attention to the fact that risk from the perspective of the decision-maker necessarily needs to see beyond (C,Q); judgments of the background knowledge K of the analysts are an integral part of the management’s and the decision-maker’s risk description and evaluation. Thus, this risk description of the analyst is (C,Q|K), whereas the management and the decision-maker need to reflect on the unconditional description (C,Q,K), seeing K as containing potential risk sources. Ways of characterizing this risk are presented and discussed. An example from the oil and gas industry is used to illustrate the discussions and show the importance for the practice of risk assessment and management.

Deployment of Digital NDT Solutions in the Oil and Gas Industry

2020 ◽  
Vol 78 (7) ◽  
pp. 861-868
Author(s):  
Casper Wassink ◽  
Marc Grenier ◽  
Oliver Roy ◽  
Neil Pearson
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Industry

What Does Rent Give to Federal Budget (on the Russia's Budget Dependence upon "Oil Dollars")

2004 ◽  
pp. 51-69 ◽  
Author(s):  
E. Sharipova ◽  
I. Tcherkashin
Keyword(s):  
Oil And Gas ◽  
Strong Dependence ◽  
Oil Prices ◽  
Federal Budget ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Resource Rent ◽  
Tax Legislation ◽  
Russian Economy ◽  
The Government

Federal tax revenues from the main sectors of the Russian economy after the 1998 crisis are examined in the article. Authors present the structure of revenues from these sectors by main taxes for 1999-2003 and prospects for 2004. Emphasis is given to an increasing dependence of budget on revenues from oil and gas industries. The share of proceeds from these sectors has reached 1/3 of total federal revenues. To explain this fact world oil prices dynamics and changes in tax legislation in Russia are considered. Empirical results show strong dependence of budget revenues on oil prices. The analysis of changes in tax legislation in oil and gas industry shows that the government has managed to redistribute resource rent in favor of the state.

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