Types of Uncertainty and Their Impact on Target Risk or Reliability

Author(s):  
Luc Huyse ◽  
Shahani Kariyawasam

The main objective in using reliability based methodologies is to provide consistent safety by explicitly accounting for uncertainties in a probabilistically quantified manner. Reliability methods also allow the articulation of the level of safety. This level of consistency in safety cannot be achieved in a deterministic analysis using safety factors. However, reliability based methods can be used to calibrate and improve deterministic methods to improve the consistency of the safety level. Providing consistent safety enables optimization of maintenance activities which enables the safest system to be provided using the available resources. Currently used deterministic and reliability based methods are both examined and discussed. Gaps and areas of improvement are identified with the objective of improving safety and explicitly articulating and communicating the level of safety. Effective use of quantitative risk and reliability methodologies requires quantitative data that describes the current state of the pipeline, the anticipated future state as well as the failure limit state. In maintaining oil and gas pipelines this level of quantitative data of the pipeline is available when pipelines are in-line inspected. Although reliability-based assessments are by no means restricted to corrosion management, the reliability based maintenance program at Pipeline Research Council International (PRCI) has been foremost applied to corrosion management because in-line inspection (ILI) data is adequately accurate to perform reliability based assessments. Guidelines for a reliability based maintenance program have been developed and projects executed to validate and demonstrate the implementation of these methodologies. The main learning from these guidelines and subsequent validation projects has been useful in identifying the process for improving integrity related decision making, the sensitivities of these methodologies, the impact of physical uncertainty and knowledge uncertainty, and the challenges in defining and applying target criteria. These identified areas are explored and discussed.

Author(s):  
Shahani Kariyawasam ◽  
Warren Peterson

Reliability methods have being adopted by oil and gas operators for integrity management decisions. These methods explicitly account for all relevant uncertainties and are designed to provide consistent safety. Consequently, a risk or reliability based approach is a very appropriate basis for decision making in the face of uncertainties. However, as in the effective use of any powerful methodology the sensitivities of the method to assumptions and limitations of applicability need to be well understood. This paper presents how improvements were made to reliability based integrity program by understanding its limitations and sensitivities. First the inputs that have the highest impact on the results were identified. These inputs are the most appropriate areas for improvement and data gathering. It is also very important to understand how the results are to be used and for what purpose. The results of this particular inline inspection based reliability assessment are used to make better excavation and repair decisions. A defect-based and joint-based decision making process is essential for determining with sufficient confidence if each defect and joint is in a safe condition. Consequently, the improvements are focused on discriminating between the myriad of defects found during an inline inspection run. Distinct field characteristics of corrosion growth are also taken into account in these improvements. The paper presents the implementation of effective area methods for future integrity probabilistic evaluations. It also describes the benefit of applying defect-specific growth rates. Finally, case studies are presented to demonstrate the effectiveness of the changes.


Author(s):  
Federico Barranco Cicilia ◽  
Alberto Omar Va´zquez Herna´ndez

Tether system is a critical component for the TLPs, since its failure may lead to the collapse of the whole structure involving human lives, economic losses and damages to the environment. Due to this fact, reliability methods have been proposed to design TLP tethers and new codes are being developed to increase their safety level. The objective of this paper is to compare the probability of failure for TLP tethers considering the maximum tension limit state obtained with three methods, which are: a methodology based on Evolutionary Strategies and the Monte Carlo Importance Sampling, the First Order Reliability Method, and the Second Order Reliability Method. Von-Mises failure criterion is used as limit state function for the most loaded tether of a TLP submitted to different sea states. Efficiency of the ES algorithm to find design points and probabilities of failure obtained with the reliability methods are discussed.


2010 ◽  
Author(s):  
Elshan Hajizadeh ◽  

Purpose - an analysis and assessment of the current state of the manufacturing infrastructure building oil and gas sector of Azerbaijan, its role and importance in the economy, as well as assessment of the impact of this sector to the socio-economic development. Findings are evaluation of role and importance of oil and gas sector in GDP in 1988-2011, forecasting of this sector impact on economic growth in the short and medium term. Originality - evaluate the role and importance of oil and gas sector in the years 1988-2011 in the structure of the runway, the forecast of its impact on socio-economic development in the short and medium term.


2012 ◽  
Vol 220 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Sandra Sülzenbrück

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.


2019 ◽  
Vol 16 (6) ◽  
pp. 50-59
Author(s):  
O. P. Trubitsina ◽  
V. N. Bashkin

The article is devoted to the consideration of geopolitical challenges for the analysis of geoenvironmental risks (GERs) in the hydrocarbon development of the Arctic territory. Geopolitical risks (GPRs), like GERs, can be transformed into opposite external environment factors of oil and gas industry facilities in the form of additional opportunities or threats, which the authors identify in detail for each type of risk. This is necessary for further development of methodological base of expert methods for GER management in the context of the implementational proposed two-stage model of the GER analysis taking to account GPR for the improvement of effectiveness making decisions to ensure optimal operation of the facility oil and gas industry and minimize the impact on the environment in the geopolitical conditions of the Arctic.The authors declare no conflict of interest


2017 ◽  
Vol 13 ◽  
pp. 244-261
Author(s):  
Mariola Tracz ◽  
Małgorzata Bajgier-Kowalska ◽  
Radosław Uliszak

Podkarpackie Voivodeship is one of the regions of Poland in which the number of agritourism entities is very high. Therefore tourism plays a significant role in its development strategy. The aim of the paper is to identify the current state of agritourism and the changes that have occurred in the region in the years 2000–2016. Specific objectives are to determine the distribution of agritourism farms and their offer, together with a comprehensive analysis of the environmental and socio-economic factors, as well as the impact of the Slovak-Ukrainian border. The report was developed on the statistical materials from the Polish Central Statistical Office, Podkarpackie Agricultural Advisory Centre in Boguchwała and data collected from municipalities and district offices that is published on their websites, as well as through interviews with 100 owners of agritourism farms in the Podkarpackie Voivodeship. The research has shown, on the one hand, the decline in the number of farms in the region and, on the other hand, the increase in the diversity of the tourist offer of these entities. Distribution of agritourism farms is closely linked to the attractiveness of natural environment and quality of secondary tourism resources. Traditional agritourism has not yet fully used its countryside, as well as cross-border advantages of its location.


2019 ◽  
Author(s):  
Chem Int

This study investigated the impact of Quality Management System (QMS) on effective service delivery in Oil and Gas Servicing Companies in selected firms in Port Harcourt, Nigeria. The opinion of 50 respondents were sampled using questionnaires, interviews as well as observation from journals and texts used in this work to examine the Quality Management System (QMS) of the selected firms. Using simple percentages and the Chi-square (X2) test of hypotheses, it was hypothetically established that the implementation of QMS practices, has impacted the work process, procedure and improvement on quality over the years in the Oil and Gas Servicing companies in Port Harcourt Nigeria. The research identified an adopted use of Failure Mode and Effect Analysis (FMEA) tool as a continual quality improvement initiative developed in the local content oil and gas servicing operation for equipment handling, management and to drive sustained improved performance quality processes as a key driver of a progressive that will place local content companies as an options for producing companies and at par with multinational oil and gas companies.


2018 ◽  
Vol 5 (1) ◽  
pp. 1-12
Author(s):  
Elias Randjbaran ◽  
Reza Tahmoorespour ◽  
Marjan Rezvani ◽  
Meysam Safari

This study investigates the impact of oil price variation on 14 industries in six markets, including Canada, China, France, India, the United Kingdom, and the United States. Panel weekly data were collected from June 1998 to December 2011. The results indicate that price fluctuations primarily affect the Oil and Gas as well as the Mining industries and have the least influence on the Food and Beverage industry. Furthermore, in three out of six of these countries (Canada, France, and the U.K.), oil price changes negatively affect the Pharmaceutical and Biotechnology industry. One possible reason for the negative relationship between oil price changes and the Pharmaceutical and Biotechnology industries in the above-mentioned countries is that the governments of these countries fund their healthcare systems. Portfolio managers and investors will find the results of this study useful because it enables adjusting portfolios based on knowledge of the industries that are impacted the most or the least by oil price fluctuations.


2020 ◽  
Vol 27 (6) ◽  
pp. 26-36
Author(s):  
A. V. Topilin ◽  
A. S. Maksimova

The article reflects the results of a study of the impact of migration on regional labour markets amidst a decline in the working-age population in Russia. After substantiating the relevance of the issues under consideration, the authors propose a methodological analysis toolkit, the author’s own methodology for calculating the coefficients of permanent long-term external and internal labour migration in regional labour markets, and the coefficient of total migration burden. In addition, the authors provide an overview of the information and statistical base of the study. According to current migration records, data of Rosstat sample surveys on Russian labour migrants leaving for employment in other regions, regional labour resources balance sheets based on the calculated coefficients of labour market pressures, the authors analyzed the impact of migration on the Russian regional labour markets over the past decade. It revealed an increasing role of internal labour migration in many regions, primarily in the largest economic agglomerations and oil and gas territories. At the same time, the role of external labour migration remains stable and minimum indicators of the contribution of permanent migration to the formation of regional labour markets continue to decrease. It has been established that irrational counter flows of external and internal labour migration have developed, which indicates not only an imbalance in labour demand and supply but also a discrepancy between the qualitative composition of migrants and the needs of the economy. It is concluded that the state does not effectively regulate certain types of migration, considering its impact on the labour market. The authors justified the need for conducting regular household sample surveys according to specific programs to collect information about labour migrants and the conditions for using their labour. In addition to the current migration records, using interregional analysis, this information allows making more informed decisions at the federal and regional levels to correct the negative situation that has developed in the regional labour markets even before the coronavirus pandemic had struck.


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