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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.
51

Experimental investigations in improving the VAPEX performance for recovery of heavy oil and bitumen

Rezaei, Nima 23 September 2010 (has links)
The process of vapor extraction (VAPEX) is a recovery process which targets the heavy oil and bitumen resources. Owing to high viscosity values for these unconventional types of oil, the recovery processes in such reserves are still challenging. The unconventional oil recovery processes usually include a mechanism for reducing the oil viscosity by means of heat, solvent, or both. The process of VAPEX utilizes the injection of a light hydrocarbon solvent into a reservoir for recovering the viscous oil in place by diffusing into the oil and by providing sufficient mobility to the oil upon dilution. Although this process offers a variety of advantages over the alternative thermal recovery processes such as SAGD or CSS, it suffers from two major drawbacks. First, the oil production rates obtained in the VAPEX process are considerably lower than those obtained in the thermal processes. Second, the solvent cost is considerably high. We tried to tackle these two problems during this research and we searched for potentials for an improved VAPEX process. Three potentially improved occurrences of a VAPEX project were found when: 1) the injected solvent was superheated, 2) the wettability of media was altered to oil-wet, and 3) the vugs were distributed in the porous media. Warm VAPEX process is introduced in which the VAPEX process is thermally augmented through superheating the solvent vapor. An attractive feature of this process is the capability of the solvent in being able to condense at the bitumen-solvent interface, which provides the opportunity for the bitumen to be upgraded in-situ through asphaltene precipitation. The asphaltene precipitation was not observed during the conventional vapor extraction process and was only observed during the warm VAPEX process. Upon a moderate level of superheating, the production rate of bitumen was sufficiently improved while the solvent content of the produced oil was significantly decreased as a result of decreased solubility of solvent in the oil at elevated temperatures. Therefore, more oil was produced at lower costs. The warm VAPEX experiments were conducted at 4 temperature levels in high and low permeability media using Cold Lake bitumen and Lloydminster heavy oil blend, n-pentane was used as solvent. The warm VAPEX process was found to be more effective for Cold Lake bitumen and for less permeable media. The potential of in-situ upgrading decreased when the level of superheating increased. The second potential for an improved VAPEX process obtained when the wettability of porous medium was altered to oil-wet conditions. Although this wettability condition is harmful to steam-based recovery processes, such as SAGD, it becomes beneficial to VAPEX. For the application of VAPEX process in fractionally wet media the wettability of glass beads was altered to oil-wet conditions through silylation process, and the VAPEX experiments were conducted in a random packing of water-wet and oil-wet beads of similar size at 7 different compositions. A substantial increase in the oil production rate was observed in a completely oil-wet medium, compared to the water-wet medium. By increasing the fraction of oil-wet beads in the packing up to a critical composition, the production rate of live oil increased linearly with the increase in the fraction of oil-wet beads in the packing during the vapor extraction process. Beyond this critical composition, however, the production rate of live oil did not change significantly with further increase in the fraction of the oil-wet beads in the randomly packed medium. Vugs were also found to be beneficial to the production performance of the VAPEX process. The presence of vugs was investigated in synthesized vugular media at 4 different levels of vuggy-to-total pore volume ratios. The performance of vugular media was compared to that of the homogeneous sintered media. The vugs facilitated the production of oil during the VAPEX process by providing flow communication between the vugs and the surrounding matrix, and therefore, by providing a local high permeability pathways towards the production well. A peak in the oil production rate was observed whenever a series of vugs were simultaneously invaded by the solvent vapor. The overall production rate of oil was higher in vuggy media compared to a homogeneous media at the same overall porosity and permeability. Furthermore, the magnitude of residual oil saturation left behind was also slightly lower in vuggy medium because the vugs were perfectly drained. Finally, a constant rate air injection (CRAI) porosimetry method was developed for characterization of vugs in a vugular media. This method was successfully tested in different synthetic vugular media, and the results illustrated higher accuracy in CRAI porosimetry method compared to constant rate mercury porosimetry. CRAI porosimetry method was also employed for identification of higher permeability regions embedded in a matrix of lower permeability. The analysis of a typical porosimetry signal was also modified.
52

Coke yield and transport processes in agglomerates of bitumen and solids

Ali, Mohamed Ali Hassan Unknown Date
No description available.
53

Design and real-time process optimisation of steam assisted gravity drainage for improved heavy oil recovery

Bali, Amol Bhagwan January 2013 (has links)
“Introduction to the Canadian Oil Sands”, “Canada’s Oil Sand Industry: An Overview”, “Heavy Oil Technologies”, and so many other topics about heavy oil have become the hotcakes in the oil industry. A number of new projects are in Execute phase for the development of heavy oil assets. This clearly shows the increasing demand for heavy oil. An oil industry is working hard to meet the world oil demand by developing deep water, HPHT, heavy oil, shale sands and all other non-conventional reservoirs but the main challenge is to develop and operate them in a risk free environment. Understanding the reservoir and fluid properties and developing new technologies help the industry to reduce the risk in developing non-conventional fields. A major problem in heavy oil field is to understand the behaviour of heavy oil. The viscous oil flows sluggishly in the formations and hence it is difficult to transport through unconsolidated formations and is very difficult to produce by conventional methods. Viscous oil recovery entails neatly designed enhanced oil recovery processes like Steam Assisted Gravity Drainage and the success of such technologies are critically dependent on accurate knowledge of reservoir, well and fluid properties of oil under variety of pressure and temperature conditions. This research project has provided some solutions to the challenges in heavy oil field development and can help the oil industry to optimise heavy oil production. Detailed experimental understanding of PVT properties has allowed this project to contribute to the knowledge. Reservoir, well and fluid properties were studied thoroughly and demonstrated the criticality of each parameter on the efficiency of Steam Assisted Gravity Drainage. An user friendly SAGD simulator is a big output of this research which allows the user to optimise the heavy oil recovery and enables to do risk assessments quickly during design phase of SAGD. A SAGD simulator is developed.
54

Estudo de óleo pesado envolto em água utilizando ferramenta CFD. / Study of heavy oil wrapped in water utilizing CFD tool.

Fabio Coffani dos Santos de Siqueira 12 February 2015 (has links)
A descoberta de petróleo na camada do Pré-Sal fez com que a Petrobras envestisse cerca de 240 bilhões de dólares. Uma etapa crítica desta indústria é o transporte de petróleo, que envolve o sistema água-óleo. O objetivo do presente trabalho é estudar uma corrente água-óleo em um tubo reto e em uma curva, com o intuito de gerar perfis de velocidades, pressões e densidades em CFD. Para as simulações desenvolvidas foram considerados: fluxo 3D, escoamento turbulento na fase óleo e escoamento laminar na fase água, isotérmico e incompressível. Foram realizados estudos nos estados estacionário e transiente. Foi desenvolvido o estudo de convergência da malha. As ferramentas do Phoenics utilizadas para representar a interação entre as fases foram o IPSA e o Algebraic Slip. O IPSA resolve as equações de Navier-Stokes para cada fase. No Algebraic Slip, postula-se que existe um meio contínuo em que existem vários componentes da fase dispersos, podendo estes ser gotas, bolhas ou partículas sólidas. A turbulência foi avaliada utilizando os modelos K- padrão e o K-, porém só houve redução considerável dos resíduos para o K- Padrão. As densidades geradas nas simulações em CFD foram comparadas visualmente com os resultados experimentais obtidos em trabalho anterior para fluxo multifásico. As quedas de pressão obtidas em simulação foram comparadas com os dados da literatura, onde foi possível observar a grande redução da perda de carga ao utilizar a técnica de envolver o óleo com um anel de água na tubulação. As simulações realizadas com o modelo Algebraic Slip, e o modelo de turbulência foram consideradas como validadas. / With the discovery of oil in the pre-salt layer, Petrobras was encouraged to invest about 240 billion dollars. A critical point of this industry is the oil transport, which encompasses oil-water system. The objective of the present work is to study the flow of water and oil into a tube and an elbow, in order to generate distributions of velocity, pressure and density by using a CFD tool. To develop simulations the following is assumed: 3D flow, turbulent flow in oil phase and laminar flow in water phase, isotherm and incompressible flow. Steady-state and transient studies have been done. The mesh convergence has been carried out. The IPSA and Algebraic slip were the Phoenics tools that were used to represent the phases interaction. The IPSA solves the Navier-Stokes equations for each phase. In the Algebraic Slip model, one assumes that a continuum mean exists where the other components are dispersed, which can be bubbles or solid particles. The turbulence was evaluated by using K- standard and K- models; however, the considerable reduction of residue to the K- Standard was observed. The densities modeled by CFD were visually compared to the experimental results that were obtained in a previous work for a multiphase flow. The simulations of head loss were compared to literature data, and it can be seen a big difference between the head loss that was obtained by using water and that no using water. The simulations of Algebraic Slip model and the use of turbulence model were considered as validated.
55

Modelagem do escoamento monofásico em bomba centrífuga submersa operando com fluidos viscosos / On the influence of viscosity upon electrical submersible pumping performance

Amaral, Gilmar Dutra Leite do 16 August 2018 (has links)
Orientador: Fernando de Almeida França / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-16T21:15:02Z (GMT). No. of bitstreams: 1 Amaral_GilmarDutraLeitedo_M.pdf: 4129101 bytes, checksum: 158cb95f0e4fa9111e692d4f3c9571dc (MD5) Previous issue date: 2007 / Resumo: Na indústria do petróleo, quando o bombeamento centrífugo submerso (BCS) é considerado como método de elevação artificial, existe a necessidade de determinar seu desempenho operando com óleos de média e alta viscosidades. O presente trabalho mostra uma proposta de criação de modelo de previsão de desempenho e comparação com dados experimentais, relativos ao desempenho de bombas centrífugas convencional e do tipo submersa, operando com fluidos viscosos. Para a construção do modelo, partiu-se das equações diferenciais da conservação da massa e quantidade de movimento para o escoamento no interior dos canais do rotor, usando abordagem unidimensional. Com o auxílio de dados experimentais, a transferência e transformação de energia no rotor, no difusor e outros elementos constituintes das bombas foram quantificadas e modeladas, compondo todo processo que ocorre em um estágio do equipamento. Para ajustar e validar o modelo teórico, foi construído um aparato laboratorial para realização de testes específicos em uma bomba centrífuga radial convencional e em dois diferentes modelos de BCSs, modelos GN 7000 e J350N, operando com água e glicerina como fluidos de trabalho. Foram adquiridos cerca de seiscentos pontos operacionais (vazão, pressão, rotação, torque e temperatura). Os testes abrangeram o seguinte universo de aplicação para as BCSs: rotação entre 1800 a 3500 rpm, vazões entre zero e 14.000 bbl/d, viscosidades de 1 cP, 60 cP, 270 cP, 720 cP e 1020 cP. Os resultados do modelo foram comparados com os valores medidos em laboratório nas três bombas testadas. Finalmente, foram comparadas também as curvas de desempenho das BCSs, obtidas no laboratório, com as curvas geradas a partir dos fatores de correção obtidos no ábaco do Hydraulics Institute-USA / Abstract: In the oil industry, when artificial lift using Electrical Submersible Pumps (ESP) is considered, there is a need to determine their performance for displacing oils of medium to high viscosity. This work proposes a model that is able to predict the performance of conventional centrifugal pumps and ESPs when pumping heavier oils (meaning oils of high viscosities). Data from experiments carried with conventional centrifugal pumps and ESPs displacing fluids of viscosity ranging from 1 cP to 1020 cP, model results and results provided by other researchers and commonly used in design procedures, were taken into account for comparisons and to provide insights for the model development. In some cases, specific and detailed measurements of pressure at different positions along the pump, from the inlet eye to the discharge section, were taken. They contributed to the model development and to understand the mechanics of the energy transfer and the conversion processes that the flow undergoes along a pump single stage or throughout the entire equipment. To obtain the experimental data a set-up was built, where one conventional centrifugal pump and two ESPs were tested. The test fluids were water (1 cP) and glycerin in different temperatures to vary the viscosity from 60 cP to 1020 cP. A heat pump and a heat exchanger were connected to the pumping system for that. The experimental results, data found in the literature and the benchmark results published by the manufacturers for pumps operating with water were compared with results calculated by the proposed model to validate it. Finally, a comparison between the experimental results and the data calculated using the procedures of the Hydraulic Institute - USA, to calculate centrifugal pump performance for viscous fluids, is presented / Mestrado / Explotação / Mestre em Ciências e Engenharia de Petróleo
56

Avaliação e aplicação dos resultados da curva PEV estendida em sistemas de processamento e refino de frações pesadas de petroleo / Evaluation and application of the extended TBP curves in processing and refining of heavy oil fractions

Cuadros Bohórquez, José Fernando 12 August 2018 (has links)
Orientador: Rubens Maciel Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-12T16:03:46Z (GMT). No. of bitstreams: 1 CuadrosBohorquez_JoseFernando_M.pdf: 955377 bytes, checksum: 373ed9ca95fec71c8fc315f656b0a361 (MD5) Previous issue date: 2008 / Resumo: A extração de petróleo no Brasil produz, em grande parte, petróleos pesados. Este tipo de óleo é de difícil processamento e gera grande quantidade de resíduos provenientes das torres de destilação atmosférica e de vácuo. É necessário fracionar esse tipo de petróleo pesado, com a finalidade de incrementar a produção de frações leves, principalmente o Diesel. A caracterização do petróleo é feita mediante as curvas PEV (Ponto de Ebulição Verdadeiro), através das normas padronizadas ASTM (American Society fot Testing and Materials); porém, a curva de destilação só pode ser obtida mediante as normas ASTM até 565ºC. Uma extensão acima dessa temperatura limite, 565ºC, foi desenvolvida pelo grupo de pesquisa do Laboratório de Desenvolvimento de Processos de Separação (LDPS) e do Laboratório de Otimização, Projeto e Controle Avançado (LOPCA), da Faculdade de Engenharia Química da Universidade Estadual de Campinas (FEQ/ UNICAMP), como apresentado em diversos trabalhos prévios (SBAITE, 2005). A metodologia desta extensão envolve o processo de Destilação Molecular, tornando possível a caracterização de frações pesadas de petróleo acima de 565ºC. A caracterização feita com a extensão da curva PEV (nova curva PEV ou DESTMOL) foi usada nesta dissertação que fez uso do simulador de processos Hysys.Plant®, mediante a geração de pseudocomponentes, para fazer a caracterização da alimentação do sistema no processo de refino. Nesta dissertação, foi desenvolvida uma metodologia de simulação para avaliar as curvas PEV estendidas no esquema de separação após o reator de FCC (Fluid Catalytic Cracking). Nesta unidade, são obtidos diferentes produtos: GLP (Gás Liquefeito de Petróleo), gasolina e diesel. O esquema de separação e um processo complexo, incluindo diferentes correntes de reciclo. Os resultados das simulações de dois tipos de resíduos de petróleo foram comparados com dados industriais, obtendo-se bons resultados. Deste trabalho, foi possível concluir que a avaliação das curvas PEV no sistema de separação após o FCC, depende das condições de projeto e de operação desta unidade, uma vez que para valores da curva PEV na alimentação acima de 550ºC, não ocorre a vaporização de alimentações com óleos mais leves, afetando significativamente a operação da unidade. Depois de fazer comparações entre os dados industriais e os dados da simulação, pode-se concluir que a avaliação deste tipo de análise (Curva PEV estendida) deveria ser feita em outro tipo de unidade, por exemplo o riser de FCC, pois este tem a capacidade de processar frações pesadas de petróleo, que é o que esta sendo representado mediante a curva PEV estendida, em frações mais leves como: gases combustíveis, GLP e nafta de craqueamento, obtidas após sua separação na unidade de fracionamento e recuperação de produtos. / Abstract: The oil extraction in Brazil is predominantly of heavy oil. This type of oil is difficult to process and it produces great quantity of residues from atmospheric and vacuum columns. It is necessary to upgrade such kind of residues in order to increase productivity of light fractions, mainly diesel. Oil characterization is made with the aid of the True Boiling Point (TBP) curve through ASTM standard test methods; however, it is possible to have this curve only until 565 ºC. An extension beyond this temperature limit was developed by this research group and it is presented in previous works in the literature, (SBAITE, 2005). For such purpose, molecular distillation process was used, which uses high vacuum as separating agent. In this sense, extension of the True Boiling Point (TBP) curve was obtained using the molecular distillation process, making possible the characterization of the heavy oil fractions of TBP higher than 565ºC. The characterization made with the extension of the TBP was used in this work in the process simulator Hysys.Plant® by the generation of pseudocomponents for characterizing the systems feeding distillation columns in the refining process. In this work, it was developed a simulation methodology in order to evaluate all the separation sequencing after the FCC (Fluid Catalytic Cracking) reactor, in order to produce different products, like (LPG), gasoline and diesel. A complex configuration characterizes this step of the refining process, including several recycle streams. The simulation results of two types of petroleum residues, Alpha 565C+ and Gamma 545C+ were compared with industrial data, yielding, very good match. From this work, it was possible to conclude that the evaluation of the TBP curves in the FCC separation steps depends on the design conditions of this unit, considering that feed at fractionation temperature above 550 ºC remains in liquid state affecting significantly the fractionator tower operation. These results are new in the open literature. After the comparisons between industrial and simulation results, can be concluded that the evaluation of this type heavy oil analysis should be performed in another unit capable to convert these products, called heavy gasoil in noble products, which can be used in the downstream FCC. This conversion process can be performed in the FCC riser. / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química
57

Escoamento trifasico vertical vertical de oleos pesados aplicado a elevação artificial / Theree-phase flow of heavy oil for application to artificial lift

Vieira, Fernando Fabris 27 August 2004 (has links)
Orientador: Antonio Carlos Bannwart / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias / Made available in DSpace on 2018-08-11T18:13:05Z (GMT). No. of bitstreams: 1 Vieira_FernandoFabris_M.pdf: 2246872 bytes, checksum: 214594df4e03b6e7638cc0a23a757366 (MD5) Previous issue date: 2004 / Resumo: As empresas de petróleo, através de seu segmento de exploração e produção - E&P - têm buscado o'aproveitamento das reservas de óleos. pesados, delimitando-as e produzindo-as de forma economicamente viável. Nessa busca, a atividade de Elevação e Escoamento tem o papel de viabilizar a movimentação desses óleos através de linhas e dutos. Um óleo é geralmente denominado pesado quando sua densidade é maior que 934 kg/m3, ou seja, seu grau API é inferior a 20, e sua viscosidade maior que 100 cP em condições de reservatório, características que dificultam sua movimentação e processamento primário. Este trabalho investiga o escoamento trifásico de misturas de óleo pesado cru com ar e água em um tubo vertical de vidro, em proporções variadas das três fases, no qual a água é injetada de forma a impedir o contato do óleo com a parede e reduzir o atrito (sistema core-flow). Para cada trio de vazões lidas nos correspondentes rotâmetros, determinou-se o padrão de escoamento com o auxílio de uma câmera de filmagem rápida (1000 quadros/segundo), e mediu-se o gradiente de pressão por meio de um transdutor diferencial de pressão. Os resultados são apresentados na forma de mapas de fluxo baseados nas velocidades superficiais e gráficos de gradiente de pressão total, possibilitando algumas comparações e interpretações. A principal conclusão aponta para a grande viabilidade da técnica de escoamento proposta. / Abstract: The oil companies, by their Exploration and Production departments (E&P), have worldwide sought viable means of recovery and prQduction of heavy oil fields, so as to aggregate and delimit those reserves in order to provide the highest revenues. In this search, the role of elevation and flow is to supply an adequate transport for these oils through lines and ducts. An oil is generally considered to be 'heavy' whenever its density is higher than 934 kg/m3 (i.e. API degree lower thari 20) and its viscosity is higher than 100 cP at reservo ir conditions; these features make it difficult their transportation and primary processing. In this work the threephase flow of a heavy crude oil, air and water in a vertical glass pipe, at several combinations of flow rates, is investigated, in which water is injected so as to avoid oil-wall contact and reduce friction (core-flow system). For each trio offlow rates read at the correspondent rotameters, the flow pattem was determined using a high speed camera (1000 ftames/second), and the pressure gradient was provided by a differential pressure transducer. The results are presented in flow maps based on superficial velocities and total pressure gradient 'plots, allowing some comparisons and interpretations. The main conclusion indicates the great viability of the proposed flow technique. / Mestrado / Explotação / Mestre em Ciências e Engenharia de Petróleo
58

Desenvolvimento de tecnicas de ultra-som para medida de espessura de filme de liquido em escoamentos gas-liquido e liquido-liquido / Development of ultrasonic techniques for measurements of liquid film thickness in gas-liquid and liquid-liquid flows

Santos, Guilherme Rosario dos 12 August 2018 (has links)
Orientador: Antonio Carlos Bannwart / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias / Made available in DSpace on 2018-08-12T11:22:37Z (GMT). No. of bitstreams: 1 Santos_GuilhermeRosariodos_M.pdf: 4731485 bytes, checksum: 22f7c73b5cfe98d8ceda0b200e009a5f (MD5) Previous issue date: 2006 / Resumo: Um dos problemas cruciais no atual cenário da indústria nacional de petróleo é a medição das vazões de óleo, gás e água produzidos por cada poço. Este problema se agrava no contexto da produção de óleos pesados sob condições offshore em águas profundas, dadas as condições adversas desse ambiente, alta viscosidade do óleo, formação de emulsões com água, dificuldade natural para sua elevação e escoamento, entre outras. Excetuando os casos em que um poço é testado, quando então sua produção pode ser determinada na superfície, não se dispõe atualmente de sistemas e métodos de medição simples, confiáveis e não-intrusivos para as vazões de cada poço. O presente trabalho investiga a utilização de técnicas de ultra-som para fins de monitoramento do filme de água em escoamentos gás-líquido e líquido-líquido. O objetivo deste trabalho é desenvolver uma ferramenta de medição de espessura instantânea do filme líquido em escoamentos gás-líquido e líquido-líquido utilizando técnicas de ultra-som. A medição do tempo de trânsito do sinal acústico ultra-sônico através de uma camada de material - líquido, gás ou sólido - permite a obtenção da espessura local e instantânea dessa camada, a partir do conhecimento da velocidade de propagação do som nesse meio, através de calibração prévia. Assim, por meio de diversos experimentos com diferentes pares de fluidos e padrões de escoamento, pretende-se definir as melhores condições para utilização do ultra-som para esse fim. Os tempos de trânsito podem ser detectados através dos picos de amplitude gerados quando os pulsos refletidos atingem o receptor. A utilização do ultra-som é uma técnica não intrusiva e não-invasiva, isto é, não causa perturbações ao escoamento, possibilitando ainda medições in situ em tempo real de grandezas de escoamentos múltifásicos presentes inclusive na indústria do petróleo. Este estudo mostrou ser possível a aplicação da técnica de ultra-som paia escoamentos gás-líquido, uma vez que a diferença de impedância acústica permite que grande ,parte do pulso incidente seja refletida na interface entre os dois meios líquidos. Em escoamentos líquido-líquido, o monitoramento da espessura de filme é mais difícil, sendo necessário o uso de recursos computacionais mais robustos. A pequena diferença de impedância acústica entre os líquidos, muitas vezes, dificulta a captação do pulso correspondente à interface entre os meios líquidos. Um outro fator agravante é a presença de emulsões em escoamentos líquido-líquido ou óleos com viscosidades maiores. Nessas situações, a atenuação do pulso refletido na interface entre os dois meios líquidos é ainda maior. / Abstract: One of the most important problems in the current scenario of petroleum industry is the flow rate measurements of oil, gas and water produced by each well. This problem becomes more complicated in the context of heavy oils production under offshore conditions in deepwater, due to the adverse environment, high oil viscosity, formation of emulsion with water, difficulties for its lift and flow, etc. Excepting the cases in which a well is being tested, when its flow rate can be determined at the surface, it does not exist any simple, reliable and non-intrusive system or measurement method for flow rate of an individual well. The present work looks over an application of ultrasonic techniques for monitoring of water film in gas-liquid and liquid-liquid flows. The specific purpose of this work is to develop a toei for instantaneous thickness measurement of liquid film in gas-liquid and liquid-liquid flows by ultrasonic techniques. The transit time measurement of an acoustic signal through a material layer (solid, liquid or gas) allows its local and instantaneous evaluation, knowing the ultrasound propagation speed for each medium from previous calibration. ln this way, through several experiments with different fluid pairs and flows pattems, it intends to establish the better conditions for application of the ultrasound technique. The transit times can be detected through the amplitude peaks generated when the reflected pulses reach the receiver. The ultrasound application is a non-invasive and non-intrusive technique, that is, it does not cause any disturbance in the flow, allowing in situ measurements in real time of many parameters of multiphase flows inc1uding the petroleum industry. This study showed the possibility of applying a pulse-echo technique t6 the gas-liquid flows, because the acoustic impedance difference allows the majority of incidem,t ultrasound be reflected in the gas-liquid interface. The monitoring of liquid films thickness is more difficult in liquid-liquid flows, being necessary the use oi rugged computational resources. The low difference of acoustic impedance between liquids can make more difficult the reception of a pulse which corresponds to the liquid-liquid interface. Another difficulty occurs when emulsions are formed or the oil is highly viscous. ln these situations, the attenuation of reflected ultrasound from the liquid-liquid interface is still larger. / Mestrado / Explotação / Mestre em Ciências e Engenharia de Petróleo
59

Padrões de fluxo e perda de carga em escoamento trifasico horizontal de oleo pesado, agua e ar

Trevisan, Francisco Exaltação 12 January 2003 (has links)
Orientador: Antonio Carlos Bannwart / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica, Instituto de Geociencias / Made available in DSpace on 2018-08-03T21:05:55Z (GMT). No. of bitstreams: 1 Trevisan_FranciscoExaltacao_M.pdf: 3270691 bytes, checksum: fe9889927a406d7a231ce2e2e37eb5cc (MD5) Previous issue date: 2003 / Resumo: Considerados de grande importância na indústria de petróleo, os óleos pesados constituem grande parte da reserva nacional, e mundial, a ser explotada e produzida. Devido a dificuldades associadas às características desfavoráveis deste tipo de óleo, como viscosidade e densidade, tem-se procurado métodos que viabilizem economicamente sua produção e transporte. Uma dessas técnicas é o core flow, que consiste basicamente na injeção lateral de pequenas quantidades de água junto ao óleo para que a primeira lubrifique o escoamento. Entretanto com a queda de pressão ao longo da tubulação, é inevitável que haja o desprendimento do gás inicialmente em solução no petróleo, o que altera as características do escoamento bifásico óleo pesado-água. Neste trabalho foram feitos testes experimentais para obter diversas informações sobre os padrões de fluxo em escoamento horizontal e as queda de pressão correspondentes. Foram elaborados mapas de fluxo onde se encontram os diversos padrões observados para cada trio de vazões de cada fase escoada. Os gradientes de pressão obtidos foram apresentados em forma de cartas e também comparados com outros tipos de fluxo, para melhor avaliar o comportamento das perdas de carga. Além disso, foi elaborado uma correlação matemática que prevê o gradiente de pressão estimando uma viscosidade equivalente do fluxo trifásico. A presença do gás aumentou o gradiente de pressão, porém o método de injeção de água para o transporte de óleos pesados provou ainda ser eficaz / Abstract: Considered to be of great importance to the oil industry, heavy oils represent a significant part of national, and worldwide, unexploited reserves. Do to the difficulties associated with the unfavorable characteristics ofthis type of oil, such as viscosity and density, heavy oil economic production and transportation techniques are being studied. One of these methods is the core flow, which consists on the lateral injection offew amounts ofwater that lubricates the oil flow. However, the pressure drop along the tube makes the gas dissociation inevitable, which wiIl alter the oil-water flow characteristics. This work presents an experimental study done to obtain more information on horizontal three-phase flow pattems and the corresponding pressure drop. Flow maps were developed, where the observed pattems were related to its corresponding superficial velocity trios. The obtained pressure gradients are presented in graphic forms and compared to other flow types, for a better evaluation of its behavior. A mathematical correlation that predicts the pressure loss by estimating an equivalent viscosity was also developed. Despite the pressure gradient increase, caused by the gaseous phase, the technique of water injection for the transport ofheavy oil has still proven to be efficient / Mestrado / Explotação / Mestre em Ciências e Engenharia de Petróleo
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Etude expérimentale et numérique de la combustion in-situ d’huiles lourdes / Experimental and numerical study of heavy oil in-situ combustion

Lapene, Alexandre 16 March 2010 (has links)
Ce travail de thèse, réalisé en collaboration avec l’IMFT et TOTAL, traite de la modélisation de la combustion in-situ appliquée à une huile lourde Vénézuéliène. Il a été initié suite à une observation simple : même si le procédé est étudié depuis plusieurs décénies, on ne peut pas encore le modéliser correctement. Des résultats expérimentaux, issus d’expérience à l’échelle du laboratoire (tubes à combustions), ne sont pas reproductibles avec des outils numériques commerciaux de types simulateurs réservoirs thermiques. Par conséquent, et face à ce constat, nous avons été contraint d’explorer plusieurs pistes pour améliorer la modélisation du procédé : – La chimie et les méthodes de détermination de mécanismes réactionnels. – La description thermodynamique d’une huile lourde et le calcul d’équilibre triphasique. – Le transport de masse et de chaleur dans un milieu poreux, en situation multiphasique, réactive et miscible. – La conception d’un modèle mathématique et numérique d’un modèle complet. Nous pensons que le problème pluridisciplinaire et fortement complexe peut trouver une réponse si l’ensemble des mécanismes et leurs liens sont traités de façon adéquate. Une campagne expérimentale (expériences de cellules cinétiques), portant sur l’étude des effets de l’eau sur les réactions chimiques de l’huile, a permis de mettre en évidence des effets inattendus et nouveaux. Ces données, complétées par des expériences de types tubes à combustion, fournissent une importante base de données expérimentale. Pour modéliser les expériences de cellules cinétiques, nous avons tout d’abord développer un nouvel outil de simulation directe, reposant sur une description compositionnelle de l’huile où les comportements de toutes les phases sont prédits par les équations d’états. Le calcul d’équilibre est fait grâce à un flash diphasique. Afin de déterminer un mécanisme réactionnel paramétré, nous avons couplé ce dernier outil à un algorithme génétique. Finalement, dans le but de simuler les expériences de tubes à combustion, un nouveau simulateur compositionel, triphasique, thermique et réactif a été développé. Il est spécialement adapté à la simulation de ce genre d’expérience. Le calcul d’équilibre de phase est réalisé grâce à un nouvel outil développé pour l’occasion. Ce dernier repose sur l’hypothèse free water et repose sur une formulation originale et novatrice. / The study of this PhD, realized jointly with IMFT and TOTAL, deals with modeling of in-situ combustion applied to a Venezuelan heavy oil. It has begun with a relatively simple observation: even if the process has been extensively studied since some decades, we cannot correctly model it. Experiment data provided by lab scale experiments (combustion tubes) mismatches numerical results obtained from commercial thermal simulator, especially for wet experiments. The need to better understand the process related to this issue forced us to explore multiple tracks for various scientific fields. Thus, one can cite: • The chemistry and methods of reduction of reactive mechanisms. • The thermodynamic description of the heavy oil and the calculations of three-phase equilibrium. • Heat and mass transport in multiphase, reactive and miscible porous medium. • Mathematical and numerical design of a full model. The problem exceedingly complex can find a complete and consistent answer if one takes into account the whole mechanisms and links between them. We have followed this way in order to determine a robust reactive scheme using both theoretical numerical and experimental developments. A whole set of kinetic cell manipulations was conducted to better understand and discriminate the effects of water on chemistry on a certain type of heavy oils. New interactions and effects on steam on heavy oil combustion have been discovered and studied. These manipulations, supplemented by a set of some combustion tubes provide a large set of experimental data. This will compose our base case that we will try to match later using some new tools devised during this study. To model kinetic experiments, we firstly developed a new simulation tool based on a compositional description and a full equation of state formulation. Equilibrium calculation is made by a two-phase flash. To determine consistent kinetic parameters, we used a genetic algorithm coupled with the new tool. Finally, in order to validate the kinetic model and simulate combustion tube experiment, a new threephase compositional simulator has been developed. It is especially fitted to take into account characteristic of the experimental device. Three-phase equilibrium calculation is computed by a new free-water

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