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2. METODOLOGÍA PARA EL DISEÑO DE BACHES EN UN PROCESO DE INYECCIÓN DE POLÍMEROS PARA RECOBRO MEJORADO, CONSIDERANDO FENÓMENOS DE INTERACCIÓN ROCA/FLUIDOS
- Author
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Ana María Jiménez Molano, Samuel Fernando Muñoz Navarro, and Robinson Jiménez Díaz
- Subjects
Polymer injection ,polymer slug ,analytical models ,numeric simulation ,methodology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Renewable energy sources ,TJ807-830 - Abstract
Polymer Injection is an enhanced recovery process meant to improve conventional water flooding. This technique takes advantage of polymer¿s solution viscosity to control fluids formation mobility and generate an uniform reservoir coverage, resulting in a better oil displacement. Due to actual needs of increasing hydrocarbon reserves through production optimization strategies, implementing this process is attractive in water flooding fields where recovery of hydrocarbon has not met expectations. To increase the probability of success, it is critical for the process, designing the right slug to be injected, since the nature of flow through porous media is governed by fluid- rock interaction that may affect flooding efficiency. The pill has to be big enough to withstand loss or change of polymer concentration preserving physical and chemical slug properties during the process. Understanding this phenomenon during design stages is very important to ensure acceptable flow during minimum required time. This paper develops a methodology to design polymer slugs during a chemical injection process based on rockfluid interactions phenomena in porous media, starting from a computerized tool during pre-design stage, involving analytical models available through a sensitivity analysis of the design parameters and observe behaviours of the polymer concentration on the injected fluid as a function of time and length; and how interaction phenomena within reservoir affects its performance. Additionally, since analytical models do not take into account all diffusion, dispersion and adsorption phenomena on the rock, a simulation model (sector model) was developed on the STARS platform from CMG Ltd. to model chemical injection projects, where obtained results from computerized tools are processed through a sensibility analysis of operational parameters that affect the process. Considering Recovery factor analysis, production rates, water front velocity, flooding efficiency and water cut, the optimized operational conditions can be obtained. Once the best operational conditions for design concentration, injection rate and time are encountered, the next step is to include them in the simulation model for final analysis. Finally, obtained results allowed stablishing a methodology to design slugs during polymer injection using a computerized tool to pre- design the slug, that involves analytical models such as Fick law, Perkins model, Warren model, Bentsen method and El- Khatib model which are based on the rock- fluid interaction within the porous media and finalising with a reservoir numeric simulation to validate the results.
- Published
- 2014
3. Avaliação da disponibilidade de video surveillance as service (VSAAS)
- Author
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MÁGNO, Carlos and MACIEL, Paulo Romero Martins
- Subjects
Disponibilidade ,CTMC ,Analytical Models ,Computação em Nuvem ,Cloud Computing ,VSaaS ,SPN ,Availability Disponibilidade ,Modelos Analíticos ,RBD - Abstract
CNPq Nos últimos anos, sistemas de Video Surveillance as a Service (VSaaS) apresentam um aumento significativo na demanda por técnicas de segurança que elevem os níveis de confiabilidade do serviço. Em paralelo, o paradigma de Computação em Nuvem tornou-se uma importante ferramenta para serviços remotos da computação. O VSaaS entrega armazenamento de grande quantidade de dados. Em 2012, 50% do armazenamento em big data que necessitou serem analisados foram de vídeo de vigilância. Em geral, os vídeos têm um alto significado para seus proprietários, não permitindo longos períodos de interrupção. Com o objetivo de evitar baixos desempenhos e ampliar a qualidade dos serviços de vídeo são necessários mecanismos para garantir alta disponibilidade em VSaaS. Entretanto, esta tarefa é difícil sem gerar impacto no custo. O presente trabalho propõe dois sistemas de VSaaS que foram submetidos a análise de disponibilidade, por meio de modelos analíticos (RBD, CTMC e SPN). O primeiro sistema, denominado doméstico, foi caracterizado pelos elementos essenciais para uma estrutura básica do VSaaS para ser utilizado em casas e pequenos comércios. Estes sistemas geraram três arquiteturas que foram modeladas para a obtenção de fórmulas fechadas, elas são importantes para realização de análises. O modelo da arquitetura 1 foi validado e as outras arquiteturas variaram dessas. A arquitetura 3 teve a maior disponibilidade entre as outras arquiteturas, por possuir a quantidade maior de componentes replicados. O downtime (em horas) desta arquitetura comparada com a sem replicações foi em 36,89%. Por ela ter a maior disponibilidade, foi realizada uma análise de sensibilidade que mostrou o componente “Node” como o de maior impacto. No segundo sistema, foi apresentado um VSaaS de uma empresa, chamado empresarial, gerando 18 (dezoito) arquiteturas, uma delas comparada a arquitetura A1 (sem redundância), obteve uma redução significativa do downtime de 30% com um pequeno aumento no custo na ordem de 7%. Caso um determinado serviço exija um downtime menor, outra análise apontou uma arquitetura com redução de 80% ao aumentar 30% do custo. Diante desse panorama foram propostas e analisadas arquiteturas que podem auxiliar administradores a tomar importantes decisões na implementação de VSaaS. In the last few years, Video Surveillance as a Service VSaaS has shown the significant increase in demand for security mechanisms to ensure reliability higher levels. In parallel, the Cloud Computing paradigm has become an important tool for remote computing services. VSaaS, for example, allows for storage large amounts of data. In 2012, 50% of big data storage were surveillance video and in general, videos have a high significance for their owners, not allowing long periods interruption. To avoid video services with low performance and increase the quality, mechanisms to ensure high availability in VSaaS are required. However, this task is difficult without generating a major impact on cost, so this paper proposes two VSaaS systems who underwent an availability analysis, using analytical models (RBD, CTMC, and SPN). The first system, entitled domestic, was characterized by essential elements of a basic structure VSaaS, for use in homes and small businesses. This system generated three architectures that were modeled to obtain closed formulas; they are important to performing analyzes. The model architecture one was validated, and other architectures vary these. The architecture three had the highest availability of the other architectures, by owning the largest number of replicated components. The downtime (in hours) this architecture compared to a without replication was 36.89%. For having the highest availability, a sensitivity analysis showed the "Node"component as the most relevant. In the second system, was showed a VSaaS in a company and has generated eighteen architectures. One of them compared to a baseline, we obtained a significant reduction in downtime (30%) and a small increase in cost (on the order of 7%). In case, of the service requires less downtime, another analysis pointed an architecture with a reduction 80% of downtime and increased 30% in the cost. We propose and analyze architectures that can help administrators make important decisions in the VSaaS implementation.
- Published
- 2015
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