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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

[en] PARAFFIN DEPOSITION IN OIL PRODUCTION LINE / [pt] DEPOSIÇÃO DE PARAFINA EM LINHA DE PRODUÇÃO DE PETRÓLEO

FLAVIO SANT ANNA RIBEIRO 12 March 2018 (has links)
[pt] O presente trabalho visa a obtenção de um melhor conhecimento dos mecanismos de deposição de parafina em linhas de produção de petróleo, a fim de auxiliar nas atividades de manutenção preditiva, e de fornecer subsídios para o estudo da viabilidade econômica da exploração de campos petrolíferos. Os dados experimentais obtidos foram utilizados para calibrar o simulador numérico desenvolvido pela PUC-Rio. Experiências de deposição para várias condições e óleos foram realizados. O regime de escoamento foi sempre monofásico (líquido). Foi realizada uma comparação entre os dados experimentais e resultados numéricos correspondentes, tendo-se observado uma boa concordância entre ambos. / [en] This work aims at a better understanding of the paraffin deposition mechanism in oil production lines. This knowledge can be very helpful in maintenance activities and to perform economical feasibility studies of exploration of oil fields. Experimental results were used to adjust e numerical simulator developed at PUC-Rio to a number of different oils. Deposition experiments for several conditions and oils were performed. The flow regime imposed was a liquid single-phase. Comparisons between experimental results and numerical predictions showed reasonable agreement.
12

Estabilidade linear para intermitência severa em sistemas água-ar. / Linear stability for severe slugging in air-water systems.

Azevedo, Gabriel Romualdo de 15 December 2017 (has links)
Apresenta-se um modelo matemático que avalia numericamente a estabilidade do estado estacionário para escoamentos água-ar em sistemas pipeline-riser de geometria variável. Uma análise a partir da teoria de estabilidade linear é aplicada a um modelo matemático adequado ao escoamento água-ar no sistema pipeline-riser. O modelo considera equações de continuidade para a fase líquida e para a fase gasosa, admite-se escoamento unidimensional e em condição isotérmica. O líquido é considerado incompressível enquanto que a fase gasosa é considerada um gás ideal. Admite-se uma equação de momento simplificada para mistura onde despreza-se a inércia (NPW - Modelo No Pressure Wave) e o padrão de escoamento local é definido com base nas condições do escoamento e na inclinação local. Assim, a intermitência severa é controlada principalmente pela gravidade no riser e pela compressibilidade do gás no pipeline. Tanto a correlação de fluxo de deriva quanto o cálculo da queda de pressão por atrito, adotados como lei de fechamento do modelo, são determinados em função do padrão de escoamento. Injeção de gás e válvula de choke são consideradas, respectivamente, na base e no topo do riser. O modelo é aplicado à sistemas pipeline-riser com escoamento água-ar citados na literatura. Os resultados da análise de estabilidade linear numérica são comparados aos resultados experimentais e numéricos apresentando uma excelente concordância. / A mathematical model that numerically evaluates the stability of the stationary state for hilly terrain air-water flows systems is presented. Numerical linear stability analysis is performed to a suitable mathematical model for the two-phase flows in a pipeline-riser system. The mathematical model considers the continuity equations for the liquid and gas phases, one-dimensional flow and isothermal conditions. The liquid is assumed incompressible while the gas phase is considered as an ideal gas. A simplified momentum equation for the mixture, neglecting inertia (NPW - No pressure wave model) is considered and the local flow pattern is defined based on the flow conditions and the local inclination. In this way, severe slugging is controlled mainly by gravity in the riser and compressibility in the pipeline. The void fraction and friction pressure drop, utilized as closure laws, are determined based on the local flow pattern. Gas injection at the bottom of the riser and a choke valve at the top are considered. The model is applied to air-water pipeline-riser systems reported in the literature. Numerical linear stability analysis results are compared with experimental and numerical results reported in the literature with excellent agreement.
13

Sistema baseado em medidor de pressão diferencial para determinação em linha de vazões de produção em poços de petróleo. / System based on differential pressure device for in ine determination of production flow rate in oil wells.

Elson Francisco da Paz 17 December 2010 (has links)
A indústria de petróleo e gás tem trabalhado para o desenvolvimento de métodos que permitam o monitoramento e controle da produção de fluidos nos poços. Para isso são desenvolvidos equipamentos específicos para medição de vazões. Este trabalho apresenta um sistema baseado em medidores de vazão por obstrução ou pressão diferencial (placas de orifício, bocais e Venturis) para determinação em linha de vazões de produção (óleo, gás e água) em poços de petróleo. A partir das equações de conservação da massa e do momento para escoamento unidimensional e considerando escoamento isotérmico com fases incompressíveis, sem mudança de fase, com fases líquidas homogeneizadas e com escorregamento constante entre as fases líquida e gasosa, é deduzida uma relação geral entre vazão mássica total e queda de pressão. Utilizando a correlação de Chisholm para o escorregamento, é realizada uma comparação entre os resultados obtidos com o modelo homogêneo e o modelo de escorregamento constante. Por meio de uma caracterização dos fluidos em produção em estado permanente e utilizando o modelo de black oil para o sistema óleo-gás, são determinadas as vazões de produção na condição de referência. São realizadas validações dos resultados do modelo com dados experimentais obtidos numa bancada experimental em Aracaju (Sergipe) e em poços de Urucu (Amazonas). A comparação com os resultados experimentais mostra que as predições feitas com o modelo de escorregamento podem ser consideradas satisfatórias, levando-se em conta que o modelo foi desenvolvido de maneira independente, sem parâmetros de ajuste dos dados experimentais. / The oil and gas industry has been working to develop methods to monitor and control the fluid production in the wells. For this purpose, specific equipments are developed for measuring stream flows. This work presents a system based on differential pressure (or obstruction) flow meters (orifice plates, Venturis and nozzles) for online determination of production flows (oil, gas and water) in oil wells. Starting from the mass and momentum conservation equations for one-dimensional, isothermal flow and considering incompressible phases without phase change, homogenized liquid phases and constant slip between gas and liquid phases, a general relationship between total mass flow and pressure drop is derived. Using Chisholmts correlation for the slip, a comparison is made between the results obtained with the homogeneous model and the constant slip model. Through a characterization of the production fluids in steady state and using the black oil model for the oil-gas system, the production flows are determined at the reference condition. A validation is made between results obtained with the model and experimental data obtained in a rig at Aracaju (Sergipe) and in wells at Urucu (Amazonas). The comparison with experimental results shows that the predictions made with the slip model may be considered satisfactory, taking into account that the model was developed independently, without parameters adjusted from the experimental data.
14

Sistema baseado em medidor de pressão diferencial para determinação em linha de vazões de produção em poços de petróleo. / System based on differential pressure device for in ine determination of production flow rate in oil wells.

Paz, Elson Francisco da 17 December 2010 (has links)
A indústria de petróleo e gás tem trabalhado para o desenvolvimento de métodos que permitam o monitoramento e controle da produção de fluidos nos poços. Para isso são desenvolvidos equipamentos específicos para medição de vazões. Este trabalho apresenta um sistema baseado em medidores de vazão por obstrução ou pressão diferencial (placas de orifício, bocais e Venturis) para determinação em linha de vazões de produção (óleo, gás e água) em poços de petróleo. A partir das equações de conservação da massa e do momento para escoamento unidimensional e considerando escoamento isotérmico com fases incompressíveis, sem mudança de fase, com fases líquidas homogeneizadas e com escorregamento constante entre as fases líquida e gasosa, é deduzida uma relação geral entre vazão mássica total e queda de pressão. Utilizando a correlação de Chisholm para o escorregamento, é realizada uma comparação entre os resultados obtidos com o modelo homogêneo e o modelo de escorregamento constante. Por meio de uma caracterização dos fluidos em produção em estado permanente e utilizando o modelo de black oil para o sistema óleo-gás, são determinadas as vazões de produção na condição de referência. São realizadas validações dos resultados do modelo com dados experimentais obtidos numa bancada experimental em Aracaju (Sergipe) e em poços de Urucu (Amazonas). A comparação com os resultados experimentais mostra que as predições feitas com o modelo de escorregamento podem ser consideradas satisfatórias, levando-se em conta que o modelo foi desenvolvido de maneira independente, sem parâmetros de ajuste dos dados experimentais. / The oil and gas industry has been working to develop methods to monitor and control the fluid production in the wells. For this purpose, specific equipments are developed for measuring stream flows. This work presents a system based on differential pressure (or obstruction) flow meters (orifice plates, Venturis and nozzles) for online determination of production flows (oil, gas and water) in oil wells. Starting from the mass and momentum conservation equations for one-dimensional, isothermal flow and considering incompressible phases without phase change, homogenized liquid phases and constant slip between gas and liquid phases, a general relationship between total mass flow and pressure drop is derived. Using Chisholmts correlation for the slip, a comparison is made between the results obtained with the homogeneous model and the constant slip model. Through a characterization of the production fluids in steady state and using the black oil model for the oil-gas system, the production flows are determined at the reference condition. A validation is made between results obtained with the model and experimental data obtained in a rig at Aracaju (Sergipe) and in wells at Urucu (Amazonas). The comparison with experimental results shows that the predictions made with the slip model may be considered satisfactory, taking into account that the model was developed independently, without parameters adjusted from the experimental data.
15

Giant Oil Fields - The Highway to Oil : Giant Oil Fields and their Importance for Future Oil Production

Robelius, Fredrik January 2007 (has links)
<p>Since the 1950s, oil has been the dominant source of energy in the world. The cheap supply of oil has been the engine for economic growth in the western world. Since future oil demand is expected to increase, the question to what extent future production will be available is important. </p><p>The belief in a soon peak production of oil is fueled by increasing oil prices. However, the reliability of the oil price as a single parameter can be questioned, as earlier times of high prices have occurred without having anything to do with a lack of oil. Instead, giant oil fields, the largest oil fields in the world, can be used as a parameter.</p><p>A giant oil field contains at least 500 million barrels of recoverable oil. Only 507, or 1 % of the total number of fields, are giants. Their contribution is striking: over 60 % of the 2005 production and about 65 % of the global ultimate recoverable reserve (URR). </p><p>However, giant fields are something of the past since a majority of the largest giant fields are over 50 years old and the discovery trend of less giant fields with smaller volumes is clear. A large number of the largest giant fields are found in the countries surrounding the Persian Gulf. </p><p>The domination of giant fields in global oil production confirms a concept where they govern future production. A model, based on past annual production and URR, has been developed to forecast future production from giant fields. The results, in combination with forecasts on new field developments, heavy oil and oil sand, are used to predict future oil production.</p><p>In all scenarios, peak oil occurs at about the same time as the giant fields peak. The worst-case scenario sees a peak in 2008 and the best-case scenario, following a 1.4 % demand growth, peaks in 2018.</p>
16

Giant Oil Fields - The Highway to Oil : Giant Oil Fields and their Importance for Future Oil Production

Robelius, Fredrik January 2007 (has links)
Since the 1950s, oil has been the dominant source of energy in the world. The cheap supply of oil has been the engine for economic growth in the western world. Since future oil demand is expected to increase, the question to what extent future production will be available is important. The belief in a soon peak production of oil is fueled by increasing oil prices. However, the reliability of the oil price as a single parameter can be questioned, as earlier times of high prices have occurred without having anything to do with a lack of oil. Instead, giant oil fields, the largest oil fields in the world, can be used as a parameter. A giant oil field contains at least 500 million barrels of recoverable oil. Only 507, or 1 % of the total number of fields, are giants. Their contribution is striking: over 60 % of the 2005 production and about 65 % of the global ultimate recoverable reserve (URR). However, giant fields are something of the past since a majority of the largest giant fields are over 50 years old and the discovery trend of less giant fields with smaller volumes is clear. A large number of the largest giant fields are found in the countries surrounding the Persian Gulf. The domination of giant fields in global oil production confirms a concept where they govern future production. A model, based on past annual production and URR, has been developed to forecast future production from giant fields. The results, in combination with forecasts on new field developments, heavy oil and oil sand, are used to predict future oil production. In all scenarios, peak oil occurs at about the same time as the giant fields peak. The worst-case scenario sees a peak in 2008 and the best-case scenario, following a 1.4 % demand growth, peaks in 2018.
17

Acoustical Communications for Wireless Downhole Telemetry Systems

Farraj, Abdallah 14 March 2013 (has links)
This dissertation investigates the use of advanced acoustical communication techniques for wireless downhole telemetry systems. Using acoustic waves for downhole telemetry systems is investigated in order to replace the wired communication systems currently being used in oil and gas wells. While the acoustic technology offers great benefits, a clear understanding of its propagation aspects inside the wells is lacking. This dissertation describes a testbed that was designed to study the propagation of acoustic waves over production pipes. The wireless communication system was built using an acoustic transmitter, five connected segments of seven inch production pipes, and an acoustic receiver. The propagation experiments that were conducted on this testbed in order to characterize the channel behavior are explained as well. Moreover, the large scale statistics of the acoustic waves along the pipe string are described. Results of this work indicate that acoustic waves experience a frequency- dependent attenuation and dispersion over the pipe string. In addition, the testbed was modified by encasing one pipe segment in concrete in order to study the effect of concrete on wave propagation. The concrete was found to filter out many of the signal harmonics; accordingly, the acoustic waves experienced extra attenuation and dispersion. Signal processing techniques are also investigated to address the effects of multipaths and attenuation in the acoustic channel; results show great enhancements in signal qualities and the usefulness of these algorithms for downhole communication systems. Furthermore, to explore an alternative to vibrating the body of a cemented pipe string, a testbed was designed to investigate the propagation aspects of sound waves inside the interior of the production pipes. Results indicate that some low-frequency sound waves can travel for thousands of feet inside a cemented pipe string and can still be detected reliably.
18

Future North Sea oil production and its implications for Swedish oil supply regarding the transport sector : -A study on energy security and sustainability of future strategic resources

Sällh, David January 2012 (has links)
Historically, it has been negative to be dependent on only one resource, in the current situation this resource represents oil. The oil dependence is primarily in the transport sector. From a Swedish perspective oil is an energy resource mainly used in the transport sector. Much of the oil that Sweden imports has its origin in the North Sea. The oil production in the North Sea has however begun to decline, which highlights that oil is a finite resource. This also means that Sweden has to start importing oil from other countries, which may affect the Swedish energy security as these countries may be geographical further away and also be more political instable. It also implies that a transition from oil to renewable fuel within the transport sector is essential. The aim of this thesis is to study how Swedish energy security is affected by the oil production volumes in The North Sea. The thesis is divided into three parts. The first part consists of updating historical data from recent analyses on North Sea oil production (i.e. Höök and Aleklett, 2008 and Höök et al., 2009a), and also create updated forecasts of future oil production for both Denmark and Norway. The second part investigates how production declines in the North Sea affect the Swedish oil imports. The final section examines how a shift to renewable fuels within the transport sector is possible, with a focus on natural resources. Finally some recommendations are presented on how Sweden could increase their energy security regarding the transport sector by introducing renewable fuels.
19

The 19th Century Olive Oil Industry In Ayvalik And Its Impact On The Settlement Pattern

Terzi, Esra 01 December 2007 (has links) (PDF)
Ayvalik which is located on the Aegean coast of the West Anatolia made its main breakthrough in the 19th century and owe this development to olive oil production which was the main economic input of the settlement since the establishment of Ayvalik. Ayvalik was within the hinterland of izmir which was gained importance as a regional trade centre in the 19th century. Thus, Ayvalik found the way to improve its trade relations in an international level and eventually increase its olive oil production volume due to the growing demands. The new form of olive oil production / factories, developed together with the traditional house and workshop productions in the last quarter of the 19th century in Ayvalik. These three forms of production made up the second significant usage within the Ayvalik after the residential areas. The two or more floored, large volumed buildings were especially located on the shore, near to the port and trade facilities, on a flat terrain and became the most dominant and attractive buildings of the settlement. Besides the impressive industrial buildings, olive oil production itself effected the settlement pattern of Ayvalik. The main transportation axes were formed accordingly to the relationship between raw material areas and production places. The olive oil production also has an effect on the physical development direction of the settlement. The areas influenced from the negative effects of the production i.e., smell and dust were not chosen for development. The development of industrial buildings also blocked the physical relationship between the residential areas and sea. The industrial buildings such as factories, workshops and warehouses along the coast line reflect the industrial character of Ayvalik in the settlement&rsquo / s silhouette.
20

Environmental Effectiveness Analysis Of Caspian Hydrocarbon Development

Atay, Deniz 01 September 2009 (has links) (PDF)
Caspian region&#039 / s hydrocarbon deposits constitute one of the significant reserves in the world. This has caused a competition among state and non-state actors in exploiting these resources since 19th century. After the Soviet demise, the newly independent states embraced the economic gains made possible with the existence of these reserves. However oil production may have negative implications on environment, ecological balance and biodiversity if carried out in an uncontrolled manner. This study aims to identify these negative impacts and measures taken to control this process. Measures taken on national, regional and international levels are analyzed to find out the extent of their effectiveness in protecting the environment during oil operations. National legal frameworks of each littoral state, impacts of civil society organizations, regional and international legal frameworks and efforts of international organizations are evaluated. Since most of these improvements are relatively new with no viable outcome at hand, the process rather than the results is focused on. The application of time, holism and action-orientation parameters to these improvements to find out the environmental effectiveness of each shows that there is a preliminary burgeoning awareness in matters of environmental protection yielding to more effective efforts than before. Yet the economic gains remain too significant a temptation for the states in the region to be sacrificed. In the cases where measures taken to protect the environment undermine these economic gains, environmental effectiveness is forsaken.

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