Author: DescomSub

DescomSub > Articles by: DescomSub
Publicações

A review of the multicriteria decision analysis applied to oil and gas de commissioning problems

29/08/2024 No Comments

Regardless of the economic activity, decommissioning decisions are often highly complex. This is due to the diversity of operational and local parameters, as well as the multitude of stakeholders involved, who generally have conflicting interests. This sets up a challenging multi-criteria decision problem on the activities to be carried out during the decommissioning process. This paper aims to present an overview of decision-support tools applied to decommissioning and covers many economic sectors, with a focus on the oil and gas sector and on multi-criteria decision analysis (MCDA) methods. The paper delves deep into the aspects to be considered before reaching a decision, examining the experiences and methods found both in industrial reports and in academic papers.

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Dimensionality reduction for multi-criteria problems: An application to the decommissioning of oil and gas installations

29/08/2024 No Comments

This paper is motivated by decommissioning studies in the field of oil and gas, which comprise a very large number of installations and are of interest to a large number of stakeholders. Generally, the problem gives rise to complicated multi-criteria decision aid tools that rely upon the costly evaluation of multiple criteria for every piece of equipment. We propose the use of machine learning techniques to reduce the number of criteria by feature selection, thereby reducing the number of required evaluations and producing a simplified decision aid tool with no sacrifice in performance. In addition, we also propose the use of machine learning to explore the patterns of the multi-criteria decision aid tool in a training set. Hence, we predict the outcome of the analysis for the remaining pieces of equipment, effectively replacing the multi-criteria analysis by the computational intelligence acquired from running it in the training set. Computational experiments illustrate the effectiveness of the proposed approach.

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Decommissioning in Brazil: Legal aspects of a technical analysis

29/08/2024 No Comments

This paper presents legal contributions to the technical analysis of the decommissioning stages
of the oil industry. We seek to contribute to decision making based on multicriteria analysis about
the options for uninstalling specific equipment in the production chain: subsea equipment. The
objective is to demonstrate that there is legal predictability supported by the technical aspect for the
options that are possible in each case. The methodology used was the literary revision combined
with a national and international legislative analysis that allowed the presentation of the final conclusion.
The comparison between the international norms, as well as the Brazilian legislation, in particular,
the national solid waste policy demonstrated the legality of the application of a multicriteria
analysis to base the decisions by the companies, as well as the inspection agencies.

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A Markov Chain Approach to Multicriteria Decision Analysis with an Application to Offshore Decommissioning

29/08/2024 No Comments

This paper proposes a novel approach that makes use of continuous-time Markov chains
and regret functions to find an appropriate compromise in the context of multicriteria decision
analysis (MCDA). This method was an innovation in the relationship between uncertainty and
decision parameters, and it allows for a much more robust sensitivity analysis. The proposed
approach avoids the drawbacks of arbitrary user-defined and method-specific parameters by defining transition rates that depend only upon the performances of the alternatives. This results in a flexible and easy-to-use tool that is completely transparent, reproducible, and easy to interpret. Furthermore, because it is based on Markov chains, the model allows for a seamless and innovative treatment of uncertainty. We apply the approach to an oil and gas decommissioning problem, which seeks a responsible manner in which to dismantle and deactivate production facilities. The experiments, which makeuseofpublished data on the decommissioning of the field of Brent, account for 12 criteria and illustrate the application of the proposed approach.

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DIVING INTO SUBSEA DECOMMISSIONING: THE CHALLENGE OF AN ECONOMIC APPROACH BEYOND COSTS MODEL

29/08/2024 No Comments

This article aims to identify national and international studies and practical experiences in the economic analysis related to subsea decommissioning, in order to identify the best alternatives applied to the Brazilian case. Since the country has a schedule of offshore structures to be decommissioned in the coming decades, studies are needed to support public policymakers by proposing sustainable strategies in line with international standards and practices. To this end, the methodology initially used a literature review based on bibliometric analysis, using scientific publications available on the Scopus and Web of Science databases. Lastly, the article highlights the importance of the multi-criteria analysis to define decommissioning alternatives considering not only economic results, but other perspectives, such as social, environmental, and waste. As the main results, the research identifies the lack of literature and the sectoral limitations of current best practices worldwide. The main reasons for those limitations are the disparity of projects and technological and regional characteristics, and consequently difficulties for costs measurements and benchmarking; lack of professional capabilities on sustainable subsea decommissioning, limited availability of studies, and fragmented regulatory approach on this matter.

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DECOMMISSIONING OF UMBILICALS AND FLEXIBLE PIPES – A SENSITIVITY ANALYSIS IN DECISION-MAKING PROCESS

29/08/2024 No Comments

The decommissioning of subsea equipment is a reality in Brazil and worldwide, highlighting the need for the development of decision-making methodologies for application in decommissioning projects. In Brazil, the volume of umbilicals and flexible pipes to be decommissioned in the future is huge, and an analysis of the best decommissioning alternative would be desirable. Based on a decision-making methodology developed by a COPPE/UFRJ research group, this work aims to present the technical criterion for the decommissioning decision-making process and a sensitivity analysis regarding the approach developed for this criterion. Among five different criteria, the proposed technical approach is composed of two sub-criteria – Complexity of Operations and Technological Risk – allowing us to assess the complexity of execution and operational activities of decommissioning alternatives and the technological risk associated with them. The decommissioning alternatives were divided into two groups – leave in situ and removal – and a total of six alternatives were considered in this study. The analyses developed show the influence of different parameters in the methodology results, emphasizing the robustness of the proposed methodology. Also, this work presents a preliminary indication for various decommissioning scenarios, varying combinations of water depth, structural integrity, cleaning status, and other factors. The results obtained in this work contribute to the consolidation of a robust methodology for the application and foundation of decision-making in decommissioning projects for flexible and umbilical lines.

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A NEW MULTI-CRITERIA DECISION-MAKING TOOL FOR SUBSEA OIL AND GAS ASSET DECOMMISSIONING

29/08/2024 No Comments

The designed life of many offshore O&G facilities is reaching its end. Decommissioning these facilities has become a critical task due to unpredictable costs, high operational risks, potential social impacts, and finally, environmental protection issues. Decision-making plays a decisive role in finding a trade-off between the concerns and interests of stakeholders such as O&G companies, government bodies, environmental protection organizations, sea and coastal environment users, and local communities. The decision problem is often complex as it usually involves several criteria. Most of the time, there is no one perfect option available to suit all the criteria: an ‘ideal’ option does not usually exist. Therefore, a compromise must be found. To address this problem, the decision-maker may use advanced approaches such as Multi-Criteria Decision Analysis (MCDA). These models have recently attracted the attention of the industry. Here, we describe a new tool that improves the decision-making process by ranking the different decommissioning options of O&G subsea assets. This model considers 37 attributes gathered into 6 criteria: Safety, Environment, Waste management, Technical, Social, and Economic. Several decommissioning alternatives are compared. The new tool has been tested on the Brazilian decommissioning of Espadarte Field, showing remarkable performance in aiding the decision-making process.

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Decisions in decommissioning projects: Bringing health and safety closer to future work.

29/08/2024 No Comments

Decommissioning in Brazil faces challenges regarding the safe and efficient deactivation of industrial facilities, considering risks such as safety and health. Associating decommissioning with operational risk management methodologies can bring benefits in resource savings, worker safety, assessment of future scenarios, and transparency and accountability among stakeholders and society at large. This study aims to perform a comparative analysis of Worker Health and Safety data criteria using a multicriteria decision analysis methodology developed by COPPE/UFRJ, to define the best decommissioning alternatives for subsea installations, using data presented by the SAFETEC (Safety and Environmental Technology) Report and the CNAE (National Classification of Economic Activities) in the context of operational risk analysis. In the Brazilian scenario, worker safety involves challenging and industry-specific issues, and understanding the activities that are effectively carried out in decommissioning could prompt reflection on future work and contribute to mitigating the operational risks to which workers in this sector are exposed.

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Energia e direito regulatório sustentável: Um estudo de caso sobre o descomissionamento na indústria do petróleo no Brasil

29/08/2024 No Comments

O desenvolvimento sustentável como pauta da agenda mundial é uma realidade que deve ser buscada por cada setor, por cada empresa, por cada agente econômico. Na indústria do petróleo, o novo segmento que tem se desenvolvido de modo mais consistente nos últimos anos, chamado de descomissionamento já nasce apoiado em critérios de sustentabilidade bastante objetivos conforme se apresenta no presente trabalho. Este novo segmento do setor petrolífero nacional representa um significativo estudo de caso para se observar como é possível por meio de um alinhamento regulatório com a agenda sustentável do país buscar caminhos menos poluentes, menos agressivos ao meio ambiente. Por meio de revisão literária combinada com uma análise legislativa nacional e internacional busca-se apresentar cenários possíveis para o descomissionamento que contribuam com o desenvolvimento sustentável, em especial com o cumprimento dos objetivos de desenvolvimento sustentável promovidos pela ONU. Em relação aos resultados, as pesquisas seguem em andamento para que haja conclusões eficazes.

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Invasive marine species and the decommissioning of offshore oil and gas installations: Challenges and sustainable management

29/08/2024 No Comments

Oil and natural gas (O&G) industries are significant players in the global economy. The lifecycle of O&G installations has reached an age at which many must be decommissioned. Biological invasion is the process by which a species is introduced into a new geographic region caused by the interference of human activities. Scientists and policymakers have identified invasive species as a significant threat to marine ecosystems affecting biodiversity. Today, O&G habitats and invasive species represent only 9% of biodiversity studies relative this field. We provide an overview of invasive species linked to decommissioning operations worldwide and emphasize the Brazilian context to support the sustainable management of decommissioning operations. O&G facilities have contributed to the spread of invasive species, such as the bryozoan Watersipora subatra in Santa Barbara Channel (California) and the sun coral species Tubastraea coccínea and T. tagusensis in the Gulf of Mexico and the Brazilian coast. The Brazilian case highlighted in this study shows several platforms to be decommissioning, and the presence of sun coral along the coast which poses biodiversity in risk. Measures must be taken to control the sun coral dissemination and some recommendations were made in this study to support futures studies.

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