Rationale for load specifications and load factors in the new CSA code for fixed offshore structures

1991 ◽  
Vol 18 (3) ◽  
pp. 454-464 ◽  
Author(s):  
Ian J. Jordaan ◽  
Marc A. Maes
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Offshore Structures ◽  
Limit States ◽  
Gas Industry ◽  
Offshore Installations ◽  
Load Factors ◽  
Annual Probability ◽  
Acceptable Risks ◽  
Economic Analyses

The Canadian Standards Association (CSA) initiated effort in 1984 aimed at the development of an offshore code for production structures in the oil and gas industry. The present paper summarizes the rationale behind the development of design load specifications in the preliminary standard S.471 "General requirements, design criteria, the environment, and loads." As part of this development, background calibration studies were conducted in tandem with the work of various committees. Selected results from these studies are also discussed in this paper. The basic objectives and tools for developing load criteria for the design of offshore installations are discussed. The use of economic analyses of cost versus safety of structures does not provide clear guidance, and the perspective taken is that of acceptable risks to an individual. This is used in the context of limit states design, which, in S.471, incorporates two safety classes. In order to provide consistent safety levels, the environmental loads are divided into categories based on frequent and rare occurrence, examples being waves and earthquakes, respectively. The role of the annual probability of failure in setting target levels of reliability as well as in the calibration process is emphasized. Various aspects of calibration are summarized, including the background to the rare-frequent separation of loads, the objective function used to optimize the results, as well as the method of handling model uncertainty. Key words: environment, limit states, loads, offshore, reliability, resistance, safety, structures.

scholarly journals ON STANDARDIZATION OF LABORATORY SOIL TESTING IN OFFSHORE GEOTECHNICAL SURVEY

Gruntovedenie ◽  
2021 ◽  
Vol 1 (16) ◽  
pp. 16-52
Author(s):  
E.A. Voznesensky ◽  
◽  
A.S. Loktev ◽  
M.S. Nikitin ◽  
◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Offshore Structures ◽  
Soil Testing ◽  
National Standard ◽  
Gas Industry ◽  
Code Of Practice ◽  
Complete Section ◽  
Testing Practice ◽  
Russian Soil

Issues of laboratory soil studies standardization in offshore geotechnical survey are discussed in connection with the end of expertise of two new regulative documents – new edition of the Code of practice and Russian national standard developed on the basis of international ISO standard. Since these documents of different level belong also to different categories (geotechnical survey and oil and gas industry), the authors analyze their interrelation and consistency, from one hand, and the preparedness of Russian soil testing practice to implementation of the new standard which results from harmonization with international ones, from the other. Complete section of the standard draft related to soil laboratory testing is presented, preceded by commentary on some important issues regarding the implementation of its specific methodic statements. It is concluded that the new national GOST draft «Petroleum and natural gas industries. Specific requirements for offshore structures. Marine soil investigations» developed on ISO basis will be a useful document supported in general by Russian normative base but expanding a possible range of voluntary methods into well time-tested foreign approaches. This documents can be considered to be a toolkit annex to the Code of practice describing testing approaches beyond the scope of typical tasks

Applying asset-and equity-based multipliers in the valuation of oil and gas corporations

2021 ◽  
Vol 27 (1) ◽  
pp. 129-167
Author(s):  
Oleg V. SHIMKO
Keyword(s):  
Oil And Gas ◽  
Stock Exchange ◽  
Balance Sheet ◽  
Oil And Gas Industry ◽  
Comparative Approach ◽  
Consolidated Financial Statements ◽  
Gas Industry ◽  
Market Capitalization ◽  
Economic Analyses ◽  
Oil And Gas Companies

Subject. This article explores the ratios of the company's market capitalization and value to the balance sheet value of assets and equity of the twenty five leading public oil and gas companies between 2008 and 2018. Objectives. The article aims to identify key trends in the changes in market capitalization and value ratios of the company to the balance sheet value of assets and equity of the largest public oil and gas companies, identify the factors that have caused these changes, and establish the applicability of these multipliers to estimate the value of the business within the oil and gas industry. Methods. For the study, I used comparative, and financial and economic analyses, and generalization of materials of the companies' consolidated financial statements. Results. The article establishes that the multipliers studied are acceptable for assessing the value of oil and gas companies, but it is preferable to use asset-based ratios. Conclusions and Relevance. The overall decline in profitability and the increase in debt load in the stock exchange sector of the global oil and gas industry should be taken into account when using multipliers based on assets and shareholder capital in the assessment of the value of oil and gas corporations through a comparative approach. The results of the study can be used to assess the possible value of oil and gas assets as part of a comparative approach and develop measures to increase the market capitalization of public oil and gas companies.

scholarly journals Offshore Helicopter Travel: Is the U.K. Oil and Gas Industry Failing Workers?

2019 ◽  
Vol 29 (4) ◽  
pp. 504-518
Author(s):  
Margaret Downie ◽  
Denise Gosling
Keyword(s):  
Trade Unions ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Shelf Area ◽  
Gas Industry ◽  
The United Kingdom ◽  
Offshore Installations ◽  
Public Inquiry ◽  
Legal Position ◽  
Continental Shelf Area

In the United Kingdom, oil and gas workers have been transported by helicopter to their workplace at offshore installations for more than fifty years. During that time, there have been numerous fatal helicopter accidents. Despite calls from trade unions, families, and politicians, a public inquiry has never been held into offshore helicopter transport. The authors consider whether enough has been done to ensure the safety of these workers to meet legal and ethical standards. They analyze the legal position, the implementation of recommendations made in the wake of these accidents, and the way in which the power imbalance between oil and gas companies and helicopter operators influences safety in this area. They conclude that a public inquiry is required into helicopter safety in the U.K. Continental Shelf area.

Stress Concentration Factors Calculation: Analytical and Numerical Approaches for Welded Tubular Joints

2020 ◽  
Author(s):  
Nathalia Paruolo ◽  
Thalita Mello ◽  
Paula Teixeira ◽  
Marco Pérez
Keyword(s):  
Stress Concentration ◽  
Oil And Gas ◽  
Hot Spot ◽  
Experimental Tests ◽  
Oil And Gas Industry ◽  
Offshore Structures ◽  
Gas Industry ◽  
Tubular Joints ◽  
Concentration Factors ◽  
Stress Concentration Factors

Abstract In the oil and gas industry, fixed platforms are commonly applied in shallow water production. In-place environmental conditions generates cyclic loads on the structure that might lead to structural degradation due to fatigue damage. Fatigue is one of the most common failure modes of offshore structures and is typically estimated when dimensioning of the structure during design phase. However, in times when life extension of existing offshore structures is being a topic in high demand by industry, mature fields may represent an interesting investment, especially for small companies. Concerning fixed platforms, composed mainly by welded tubular joints, the assessment of hot spot stresses is considered to predict structure fatigue. The estimation of welded joint hot spot stresses is based on the stress concentration factors (SCFs), which are given by parametric formulae, finite element analysis (FEA) or experimental tests. Parametric formulae may be defined as a fast and low-cost method, meanwhile finite elements analysis may be time consuming and experimental tests associated with higher costs. Given these different characteristics, each method is applied according to the study case, which will rely on the joint geometry and associated loads. Considering simple joint geometries several sets of parametric equations found in the literature may be applied. On the other hand, the SCFs calculation of non-studied yet complex joints consider known formulae adapted according to the under load joint behavior and geometry. Previous analysis shows that this adaptation may furnish different results compared to those obtained by FEA. Furthermore, it is observed that even for simple joints the results derived from the different methods may differ. Given their importance for the oil and gas industry, since they are the basis for the assessment of the fatigue life of welded tubular joints which may impact on additional costs related to maintenance and inspection campaigns, the estimation of SCFs must be the most accurate as possible. Therefore, this paper intends to investigate the differences between results derived from parametric formulae and different FEA studies.

Potential Galloping Motions of Piggyback Pipeline Geometries in Strong Currents

2012 ◽  
Author(s):  
Adeshina Elegbede ◽  
Ove T. Gudmestad
Keyword(s):  
Oil And Gas ◽  
Angle Of Attack ◽  
Oil And Gas Industry ◽  
Electrical Heating ◽  
Equivalent Diameter ◽  
Flow Induced Vibration ◽  
Gas Industry ◽  
Offshore Installations ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Piggyback configurations of pipelines, such as a Direct Electrical Heating (DEH) cable mounted on production flowlines, are becoming a common occurrence in the offshore oil and gas industry and they have been observed to excite into a type of flow-induced vibration called galloping in the presence of strong currents at free span locations. This work was aimed at studying potential flow induced galloping vibrations of piggyback type of pipelines commonly used on offshore installations in the oil and gas industry. Tests were carried out in a 12m long, 0.7m wide and 1.2m deep current flume tank located at the NTNU/SINTEF Hydrodynamic Laboratory in Trondheim, Norway. The tank has a test rig with cylinders suspended horizontally on a set of springs mounted on it. Reduced velocities were ranging from 4 to 15, depending on the equivalent diameter of the piggyback pair. In this experimental work, the effects of different diameter ratios and the angle of attack of the flow on the cylinders arranged normal to the flow were investigated. Three different diameter ratio cases were investigated: D+0.5D, D+0.32D and D+0.25D. Attack angles 0°, 30°, 60°, 90°, 120°, 150° and 180° were tested for these 3 diameter ratios giving a total of 21 test cases. The results obtained show that, for all cases of diameters ratios, high response amplitude ratios, as high as 1.7, can occur at reduced velocities less than 10 when the angle of attack is at 90°. It was also observed that vibrations that are characteristic of galloping instabilities occurred at an attack angle of 180° for the D+0.5D and the D+0.32D configurations. For the D+0.25D case, the response amplitudes were similar to a VIV situation. Comparing the response of the different diameter ratios show that the largest pipeline to piggyback ratio gives the largest responses for all attack angles.

scholarly journals Market valuation of the world's leading public oil and gas corporations as an indicator of investment attractiveness of domestic vertically integrated companies

2021 ◽  
Vol 26 (4) ◽  
pp. 414-433
Author(s):  
Oleg V. SHIMKO
Keyword(s):  
Oil And Gas ◽  
Balance Sheet ◽  
Oil And Gas Industry ◽  
Market Valuation ◽  
Net Income ◽  
Consolidated Financial Statements ◽  
Gas Industry ◽  
Market Capitalization ◽  
Economic Analyses ◽  
Oil And Gas Companies

Subject. This article explores the market valuation ratios of the twenty five leading listed oil and gas companies between 2006 and 2018. Objectives. The article aims to identify key trends in the changes in market valuations of the largest listed oil and gas companies, and identify the factors that have caused these changes. Methods. For the study, I used comparative, and financial and economic analyses, and generalization of materials of the companies' consolidated financial statements. Results. The article shows certain changes in the main indicators of market valuation of the leading listed oil and gas companies and identifies the main factors that contributed to these changes. It establishes that the most significant for comparison and valuation are ratios based on balance sheet values of assets and equity, and net sales, EBITDA, DACF and net income ratios are appropriate as auxiliary ratios. The article says that the exchange segment of the industry has increased the debt load, so instead of market capitalization as a component of the coefficients of this group, it is advisable to apply the enterprise value indicator. Conclusions and Relevance. The article concludes that the market sentiments towards the stock market segment of the global oil and gas industry are getting impaired. This is quite natural against the background of falling profitability of most leading companies. The results of the study can be useful in evaluating, forecasting and developing measures to increase the market capitalization and value of listed oil and gas companies.

ISO Offshore Structures Standards

2011 ◽  
Author(s):  
Philip Smedley ◽  
Pat O’Connor ◽  
Richard Snell
Keyword(s):  
Oil And Gas ◽  
Steel Structures ◽  
Oil And Gas Industry ◽  
Offshore Structures ◽  
National Standards ◽  
Gas Industry ◽  
Technical Content ◽  
Technical Advances ◽  
Integrity Management ◽  
Specific Assessment

The ISO 19900 series of Standards address the design, construction, transportation, installation, integrity management and assessment of offshore structures. Offshore structural types covered by ISO include: bottom-founded ‘fixed’ steel structures; fixed concrete structures; floating structures such as monohull FPSOs, semi-submersibles and spar platforms; arctic structures; and site-specific assessment of jack-up platforms. All the fundamental ISO Offshore Structural Standards have now been published representing a major achievement for the Oil and Gas Industry and representative National Standards Organizations. A summary of the background to achieving this milestone is presented in this paper. In parallel, other Codes and Standards bodies such as API, CEN, CSA, Norsok and the Classification Societies are looking to harmonize some, or all, of their Offshore Structures Standards in-line with ISO, wherever this is desirable and practical. API, in particular, have been pro-active in reviewing and revising their Offshore Recommended Practices (RPs) to maximize consistency with ISO, including revising the scope and content of a number of existing API RPs, adopting ISO language, and embracing technical content. Given API’s long heritage of Offshore Standards it is not surprising that this remains very much a mutual effort between ISO and API with much in ISO Standards building on existing API design practice. Now published, those involved in developing and maintaining the ISO 19900 series of Standards have to deal with both new and existing challenges, including encouraging wider awareness and adoption of these Standards, enhancing the harmonization effort, ensuring technical advances are captured in timely revisions to these Standards, and most pressing to ensure that the next generation of offshore engineers are encouraged to participate in the long-term development of the Standards that they will be using and questioning. This paper is one of a series of papers at this OMAE Conference that outline the technical content and future strategy of the ISO Offshore Structures Standards.

An Advanced Procedure for the Quantitative Risk Assessment of Offshore Installations

2017 ◽  
Vol Vol 159 (A2) ◽  
Author(s):  
S J Kim ◽  
J M Sohn ◽  
J K Paik
Keyword(s):  
Oil And Gas ◽  
Probabilistic Approach ◽  
Oil And Gas Industry ◽  
Quantitative Risk Assessment ◽  
Functional Requirements ◽  
Gas Industry ◽  
Qualitative Approaches ◽  
Offshore Installations ◽  
Successful Design ◽  
Accident Scenarios

Hydrocarbon explosion and fire are typical accidents in the offshore oil and gas industry, sometimes with catastrophic consequences such as casualties, property damage and pollution. Successful engineering and design should meet both functional requirements associated with operability in normal conditions and health, safety, environmental and ergonomics (HSE&E) requirements associated with accidental and extreme conditions. A risk-based approach is best for successful design and engineering to meet HSE&E requirements. This study aimed to develop an advanced procedure for assessing the quantitative risk of offshore installations in explosions. Unlike existing industry practices based on prescriptive rules or qualitative approaches, the proposed procedure uses an entirely probabilistic approach. The procedure starts with probabilistic selection of accident scenarios. As the defining components of risk, both the frequency and consequences associated with selected accident scenarios are computed using the most refined technologies. Probabilistic technology is then applied to establish the relationship between the probability of exceedance and the physical values of the accident. Acceptance risk criteria can be applied to define the nominal values of design and/or level of risk. To validate and demonstrate the applicability of the proposed procedure, an example of its application to topside structures of an FPSO unit subjected to hydrocarbon explosions is detailed. The conclusions and insights obtained are documented.

Introducing IO in a Drilling Company

2013 ◽  
pp. 370-388 ◽  
Author(s):  
Grethe Osborg Ose ◽  
Trygve J. Steiro
Keyword(s):  
Oil And Gas ◽  
New Technology ◽  
Oil And Gas Industry ◽  
Safety Level ◽  
Gas Industry ◽  
Offshore Installations ◽  
The Status ◽  
Offshore Oil And Gas ◽  
Integrated Operations ◽  
Offshore Oil

The introduction of Integrated Operations (IO) in the offshore oil and gas industry makes distanced and distributed decision-making a growing part of normal work. Some functions have been transferred from offshore installations to onshore offices as a consequence of the technologies that have recently become available. The authors analyze whether the onshore organization is ready for increased responsibilities by increasing the resilience in its work patterns, since resilience is important for maintaining or increasing safety level compared to current operation, where personnel on board installations can observe the plant at first hand. This study has been performed as a case study of an onshore Support Center in a drilling company at the start of the process of using the Support Center. The establishment of the Support Center involved re-arranging the office arrangements to an open landscape for all offshore installation support personnel and grouping them according to disciplines. They also acquired new technology, including video conference equipment. Important findings are that developing resilience has to be followed through at all levels of the organization. Time and resources have to be made available when work practices change, providing the physical framework alone does not improve resilience. The study also offers a more detailed description of capability resilience and which aspects should be considered when developing resilience. The authors look at the status so far in the change process and also find areas that should be developed in order to increase resilience further.

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