O presente trabalho versa sobre o termo de atrito em escoamento transitório em condutos forçados, partindo de uma modelação matemática da tensão de cisalhamento transiente, usando conceitos do princípio da entropia máxima. Usa-se a modelação deste termo de atrito na análise do transitório hidráulico, comparando-se com dados experimentais já publicados de um sistema Reservatório-Tubo-Válvula. / This report contains a friction term for hydraulic transient in closed conduits. We use a mathematical model for the shear stress, derived by principle of maximum entropy. Then, we use this friction term for an analysis in a system reservoir-tube-valve, comparing our results with anothers already published in the literature.

Subsea pipelines form an integral part of the infrastructure associated with offshore oil and gas developments. These pipelines fulfill a range of functions from linking extraction wells to other subsea infrastructure to transporting products onshore, or to a central processing facility. Ancillary pipelines may also be present for gas or water injection to the reservoir or transporting additives. Pipelines are typically installed directly onto the seabed and, in the absence of significant drivers to undertake burial operations, they may remain on the seabed for the remainder of their design life. This is typically the case for deepwater developments. Subsea pipelines are subjected to a wide range of load cases including, self weight, installation loads, thermal and pressure driven expansion and hydrodynamic loading. Design of pipeline systems to accommodate these load cases requires an understanding of pipe-soil interaction. This thesis reports the results of a research study investigating pipe-soil interaction on a clay seabed, as relevant to the design of subsea pipeline systems. This study has utilised numerical analysis techniques based on the finite difference code FLAC to investigate a range of problem definitions. These problem definitions include pipelines subject to both vertical loading (V) and combined vertical and horizontal (V-H) loading. Factors such as variation in interface conditions, large strain and large displacement effects, soil unit weight effects and variation in shear strength conditions were considered in these problem definitions. Reliability based analysis techniques have also been used to investigate both V and V-H loading problem definitions. The analyses and investigations undertaken as part of this study generally achieved the following; reproduction and validation of earlier research with additional interpretation, extension of problem definitions to deeper pipeline embedment depths and investigation of pipe-soil interaction problem definitions that have not previously been considered. Reliability based analysis techniques have also provided some interesting insights into the impact of soil shear strength variation as well as providing a fundamental link between safety factors and probability of failure. Application to design practice of this, and similar studies, has been considered as part of this thesis and potential areas for future research have also been suggested.

O objetivo deste trabalho foi delimitar índices de rentabilidade, tais como Taxa Interna de Retorno - TIR, Valor Presente Líquido - VPL e payback, para duas alternativas de traçado de alcoodutos selecionadas pela equipe do trabalho de UNICA et al. (2006), além de analisar se tais projetos são economicamente viáveis diante das demais alternativas de investimentos disponíveis aos agentes envolvidos. Um importante exercício foi a análise de sensibilidade do projeto à alteração de variáveis tais como valor dos investimentos, tarifa e volume captado pelo duto. Foi realizada, ainda, uma comparação entre os índices de rentabilidade obtidos no trabalho de UNICA et al. (2006) e aqueles calculados nesta dissertação. Os principais dados necessários à análise de viabilidade das alternativas selecionadas (Dutovias Conchas/ Paulínia/Campo Limpo/Santos e Conchas/Paulínia/São Sebastião) tais como extensões dos dutos, investimentos necessários, período do projeto, início das operações, tarifa cobrada pelo transporte do etanol, capacidade dos dutos, gastos com operação e manutenção e custo de capital também foram obtidos do trabalho de UNICA et al. (2006). Diante dos dados obtidos, o método escolhido para a avaliação do investimento foi o do Fluxo de Caixa Descontado FCD. Os resultados obtidos sinalizaram que diante da estrutura de investimentos, tarifa dutoviária e capacidade modular dos dutos estabelecidos inicialmente para os projetos pela equipe da UNICA, nenhum dos traçados selecionados apresenta índices de rentabilidade satisfatórios em relação à realidade de mercado. Portanto, pode-se concluir que para projetos dessa natureza, que são essenciais para o desenvolvimento da infraestrutura econômica do Brasil, são realmente necessários subsídios por parte do governo, além da participação massiva da iniciativa privada, caracterizando a necessidade de Parcerias Público-Privadas PPP. / The goal of this work was to delimit profitability indexes, as such Internal Rate of Return IRR, Net Present Value NPV and payback, for two alternatives of ethanol pipelines grids selected by UNICAs et al. (2006) working group, and to analyze if these projects are economically feasible in comparison with other investment alternatives that are available for the involved agents. The sensitivity analysis of the project in relation to some variables changes, as the investment values, tariff and volume transported through the pipeline, was an important exercise. It was also done a comparison among the resulting profitability indexes of UNICAs et al. (2006) work and those calculated in this dissertation. The main data necessary to the feasibility analysis of the selected alternatives (Conchas/Paulínia/Campo Limpo/Santos and Conchas/Paulínia/São Sebastião pipelines) as pipelines extension, necessary investments, project period, start of operations, charged tariff for ethanol transportation, pipelines capacity, operations and maintenance spending and cost of capital was also obtained in UNICA et al. (2006) work. Considering the available data, the Discounted Cash Flow DCF method was selected to make the investments evaluation. The results indicate that, considering the investment structure, pipeline tariff and modular capacity of the pipelines initially determined to the projects by UNICAs team, none of the selected grids have satisfactory profitability indexes in relation to market reality. So, it is possible to conclude that, in case of projects of this nature, which are essential to the economic and infrastructure development in Brazil, governmental subsidies are necessary, in addition to private initiative massive participation, characterizing the need of Public- Private Partnerships - PPP.

No description available.

Slurry transport is a key material handling technology in a number of industries. In oilsands ore transport, slurry pipelining also promotes conditioning to release and aerate bitumen prior to separation. Reliability of slurry transport pipelines is a major ongoing problem for operating companies due to unexpected piping failures, even when conservative maintenance strategies are employed. To date, no accurate model has been developed to predict wear rates in slurry transport pipelines, although previous studies have shown that important variables include flow rate, slurry density, and particle size distribution. This work investigates erosion wear mechanisms causing inner pipe wall wear due to sand slurry flow in a horizontal section of pipe under steady state conditions. A corresponding lumped-parameter erosion wear model is presented based on simplification of the physics of oilsands slurry flow. An apparatus was designed and developed to measure the forces acting on the pipe inner wall to monitor forces related to erosion in a laboratory-scale sand slurry loop, and preliminary results are presented with recommendations for future work. / Engineering Management

There exist various applications of transportation of slurries through pipelines all over the world. In the present study, the problem is formulated as a &quot / transportation problem&quot / to determine the pipe diameters and amounts of slurry to be transported from the demand (production) points to the processing (factory) points. The minimization of the cost consisting of the pipe and energy cost terms is considered as the objective function to determine the stated decision variables. Pipe cost is given as the function of pipe diameters and the energy cost is defined as function of pipe diameters and slurry amounts. Energy cost is obtained by using the relation that is previously determined after the experimental studies made for the magnetite ore. The optimization method used in the study is genetic algorithm method. A commercially available software written in C language is used and modified for the present study The proposed methodology to solve this nonlinear programming problem is applied to a transportation system and it is seen that the methodology made the complex, labor intensive equation solution process very convenient for the users.

Thesis (Ph.D.)--Ohio University, June, 2009. / Release of full electronic text on OhioLINK has been delayed until June 1, 2010. Includes bibliographical references (leaves 184-194)

Thesis (Ph.D.)--Ohio University, June, 2009. / Title from PDF t.p. Release of full electronic text on OhioLINK has been delayed until June 1, 2010. Includes bibliographical references (leaves 184-194)

M.Tech. Business Administration. Business School. / This research study examines processes of change management due to regulatory impact on organisations within the South African gas pipeline industry (energy industry). It concludes that a 'changing organisation' is not simply the product of good design; its existence is subject to history and to shifting power relations (i.e. Government) both within and outside of organisations.

No description available.