Orientador: Osvair Vidal Trevisan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias / Made available in DSpace on 2018-08-15T09:21:24Z (GMT). No. of bitstreams: 1 Goncalves_LuciaInesBonet_M.pdf: 4242860 bytes, checksum: dabd009f0a1e3b92481793ed9e495f64 (MD5) Previous issue date: 2010 / Resumo: Uma das formas de se melhorar o desempenho do processo de recuperação de petróleo conhecido como combustão in situ direta seca, é injetar água simultaneamente ou alternadamente com o ar, o que se denomina de combustão in situ direta molhada. O calor específico do ar seco é consideravelmente menor do que o da água, de tal forma que esta pode realizar um melhor transporte do calor gerado pela frente de combustão, promovendo uma redução na quantidade de ar requerido para varrer um determinado volume do reservatório. O presente trabalho tem como objetivos avaliar, através de ensaios em tubo de combustão, o desempenho da combustão molhada para um óleo pesado (12,88°API) procedente da Bacia do Espírito Santo e obter parâmetros que possam ajudar no balizamento de um futuro projeto piloto. Para isto, foram realizados quatro ensaios em tubo de combustão (um de combustão seca e três de combustão molhada), utilizando o aparato experimental do Laboratório de Métodos Térmicos de Recuperação do Departamento de Engenharia de Petróleo da UNICAMP e também foi elaborado um modelo térmico de simulação para auxiliar na predição dos testes em laboratório, utilizando um simulador comercial. Os resultados experimentais mostram que o processo de combustão molhada apresenta-se estável para o óleo em estudo na medida em que as condições experimentais mantêm-se controladas. Para as razões água-ar estudadas (1,00 x 10-3 m3/m3; 0,56 x 10-3 m3/m3 e 0,33 x 10-3 m3/m3), a presença da água diminui a deposição de combustível, aumentando a velocidade de avanço da frente de combustão e reduzindo a quantidade de ar requerida. É observada uma redução na temperatura média da frente de combustão (de 493 ºC para 460 ºC), mas, ainda assim, mantendo-a na faixa das reações de alta temperatura. Os resultados do modelo de simulação mostram-se próximos aos experimentais, no que diz respeito ao perfil de temperatura / Abstract: One way to improve the performance of the oil recovery method, known as dry forward in situ combustion, is to inject water either simultaneously or intermittently with the air, named as wet forward in situ combustion. The specific heat of the dry air is considerably lower than that of water, such that water may render a better transport of the heat generated by the combustion front, leading to a reduction of the amount of air required to sweep a specified reservoir volume. The objectives of the present work are to evaluate, through combustion tube tests, the wet combustion performance for a heavy oil (12,88°API) from Espírito Santo Basin and to obtain helpful combustion parameters for the design of a future field pilot. For this, four combustion tube tests were performed (one dry combustion and three wet combustions), using the experimental apparatus in the Laboratory of Thermal Methods of Recovery from the Department of Petroleum Engineering at UNICAMP, and it was also developed a thermal simulation model to help on the prediction of the lab tests, using a commercial simulator. The experimental results showed that the wet combustion process is stable for the studied oil, since the experimental conditions are kept under control. For the studied water-air ratios (1,00 x 10-3 m3/m3; 0,56 x 10-3 m3/m3 and 0,33 x 10-3 m3/m3), the presence of water decreases the fuel deposition, increasing the combustion front velocity and decreasing the amout of the air required. A reduction in the average temperature of the combustion front (from 493 ºC to 460 ºC) was observed, but still, in the range of the high temperature oxidation reactions. The results of the simulation model showed an adjustment close to the experimental ones regarding the temperature profile / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Multiphase flows are of great interest to a large variety of industries because flows of two or more immiscible liquids are encountered in a diverse range of processes and equipment. However, the advent of high viscosity oil requires more investigations to enhance good design of transportation system and forestall its inherent production difficulties. Experimental and numerical studies were conducted on water-sand, oil-water and oilwater- sand respectively in 1-in ID 5m long horizontal pipe. The densities of CYL680 and CYL1000 oils employed are 917 and 916.2kg/m3 while their viscosities are 1.830 and 3.149Pa.s @ 25oC respectively. The solid-phase concentration ranged from 2.15e-04 to 10%v/v with mean diameter of 150micron and material density of 2650kg/m3. Experimentally, the observed flow patterns are Water Assist Annular (WA-ANN), Dispersed Oil in Water (DOW/OF), Oil Plug in Water (OPW/OF) with oil film on the wall and Water Plug in Oil (WPO). These configurations were obtained through visualisation, trend and the probability density function (PDF) of pressure signals along with the statistical moments. Injection of water to assist high viscosity oil transport reduced the pressure gradient by an order of magnitude. No significant differences were found between the gradients of oil-water and oil-water-sand, however, increase in sand concentration led to increase in the pressure losses in oil-water-sand flow. Numerically, Water Assist Annular (WA-ANN), Dispersed Oil in Water (DOW/OF), Oil Plug in Water (OPW/OF) with oil film on the wall, and Water Plug in Oil (WPO) flow pattern were successfully obtained by imposing a concentric inlet condition at the inlet of the horizontal pipe coupled with a newly developed turbulent kinetic energy budget equation coded as user defined function which was hooked up to the turbulence models. These modifications aided satisfactory predictions.

[pt] A alta viscosidade dos óleos pesados e o elevado teor de asfaltenos contribuem para a formação de emulsões água-em-óleo (A/O) altamente estáveis, dificultando a separação óleo/água e aumentando os custos de produção e transporte. Para reduzir a viscosidade, técnicas de diluição são comuns com solventes simples. Portanto, pouca pesquisa foi realizada sobre o impacto dos compostos aromáticos nas propriedades interfaciais e na estabilidade das emulsões, de solventes complexos, como o querosene. Neste estudo, investigou-se o efeito da segregação dos compostos aromáticos do querosene nas propriedades bulk e interfaciais e na estabilidade dos asfaltenos e das emulsões A/O. Além disso, foram analisadas as correlações desses efeitos com a desemulsificação química. Inicialmente, foram avaliadas as propriedades interfaciais de frações de surfactantes naturais, extraídas de um óleo pesado brasileiro, em relação à sua capacidade de estabilizar emulsões água-querosene. Os resultados indicaram que a estabilidade dessas emulsões decorre do efeito sinérgico entre as resinas e os asfaltenos, resultando na formação de filmes interfaciais mais flexíveis, que evitam ou retardam a coalescência das gotas. Entretanto, quando o querosene foi utilizado como diluente do óleo pesado (HO) na fase oleosa, observou-se a floculação e precipitação dos asfaltenos. Esses resultados foram correlacionados com a composição química de dois tipos de querosene: um composto apenas por saturados (KeS) e outro contendo 30 por cento massa de compostos aromáticos (KeSA). Verificou-se que a composição química dos querosenes afeta a estabilidade coloidal dos asfaltenos, a estabilidade da emulsão e as propriedades interfaciais. KeSA apresentou maior solubilização e dispersão dos asfaltenos em comparação ao KeS. Além disso, a viscoelasticidade interfacial diminuiu quando o teor de querosene foi maior ou igual a 30 por cento massa, indicando a formação de filmes interfaciais menos rígidos. Porém, o módulo de elasticidade nos sistemas contendo KeSA aumentou gradualmente com o tempo, sugerindo uma melhor solubilidade dos asfaltenos e uma adsorção controlada pela difusão facilitada na interface. A concentração de aromáticos do solvente (KeSA) mantém a estabilidade do filme interfacial durante a diluição de HO, compensando assim a perda de asfaltenos com o aumento do teor de querosene na fase óleo. Os resultados também destacaram o papel crucial da aromaticidade do querosene na quebra das emulsões A/O contendo 20 por cento massa de Ke na fase oleosa. Diferentes desemulsificantes químicos, comumente utilizados como bases para desemulsificantes comerciais, bem como compostos modelo, foram testados. KeSA apresentou maior robustez e resistência à quebra das emulsões. Esse efeito decorre da segregação interfacial dos compostos aromáticos do querosene. Esses resultados enfatizam a importância da composição química do querosene quando é usado na diluição de óleos pesados, o qual tem efeito significativo na estabilidade e quebra das emulsões A/O. / [en] The high viscosity of heavy oils and the high content of asphaltenes contribute to the formation of highly stable water-in-heavy oil (W/O) emulsions, making oil/water separation difficult and increasing production and transportation costs. To reduce viscosity, dilution techniques with simple solvents are common. Therefore, slight research has been conducted on the impact of aromatic compounds on interfacial properties and emulsion stability from complex solvents, such as kerosene. In this study, we investigated the effect of segregation of aromatic compounds in kerosene on the bulk and interfacial properties and stability of asphaltenes and W/O emulsions. Furthermore, we analyzed the correlations of these effects with chemical demulsification. Initially, we evaluated the interfacial properties of natural surfactants fractions extracted from Brazilian heavy oil regarding their ability to stabilize water-kerosene emulsions. The results indicated that the stability of these emulsions was related to the synergistic effect between resins and asphaltenes, resulting in the formation of more flexible interfacial films that prevent or delay the coalescence of the droplets. However, when kerosene was used as diluent of heavy oil (HO) in the oil phase, flocculation and precipitation of asphaltenes were observed. These results were correlated with the chemical composition of two kerosene types: one composed only of saturates (KeS) and another containing saturates and 30 percent wt. of aromatic compounds (KeSA). It was found that the chemical composition of the kerosene affects the colloidal asphaltenes stability, emulsion stability, and interfacial properties. KeSA showed greater solubilization and dispersion of asphaltenes compared to KeS. Additionally, interfacial viscoelasticity decreased when the kerosene content was bigger or equal 30 wt. percent, indicating the formation of less rigid interfacial films. However, the interfacial elastic modulus in systems containing KeSA gradually increased over time, suggesting better solubility of asphaltenes and diffusion-controlled adsorption at the interface. The concentration of solvent aromatics (KeSA) maintains interfacial film stability during HO dilution, thus compensating for the loss of asphaltenes with increasing kerosene content in the oil phase. The results also revealed the crucial role of kerosene s aromaticity in the breaking of W/O emulsions containing 20 wt. percent of kerosene in the oil phase. Various chemical demulsifiers commonly used as bases for commercial demulsifiers, as well as model compounds, were tested. The presence of KeSA exhibited greater robustness and resistance to emulsion breaking. This effect was attributed to interfacial segregation of aromatic compounds from kerosene. These results emphasize the importance of kerosene s chemical composition when used for diluting heavy oils, as it has a significant effect on the stability and breaking of W/O emulsions, particularly in the case of the Brazilian heavy oil used in this study.

Thermal and chemical recovery processes are important EOR methods used often by the oil and gas industry to improve recovery of heavy oil and high viscous oil reservoirs. Knowledge of underlying mechanisms and their modeling in numerical simulation are crucial for a comprehensive study as well as for an evaluation of field treatment. EOS-compositional, thermal, and blackoil reservoir simulators can handle gas (or steam)/oil/water equilibrium for a compressible multiphase flow. Also, a few three-phase chemical flooding reservoir simulators that have been recently developed can model the oil/water/microemulsion equilibrium state. However, an accurate phase behavior and fluid flow formulations are absent in the literature for the thermal chemical processes to capture four-phase equilibrium. On the other hand, numerical simulation of such four-phase model with complex phase behavior in the equilibrium condition between coexisting phases (oil/water/microemulsion/gas or steam) is challenging. Inter-phase mass transfer between coexisting phases and adsorption of components on rock should properly be modeled at the different pressure and temperature to conserve volume balance (e.g. vaporization), mass balance (e.g. condensation), and energy balance (e.g. latent heat). Therefore, efforts to study and understand the performance of these EOR processes using numerical simulation treatments are quite necessary and of utmost importance in the petroleum industry. This research focuses on the development of a robust four-phase reservoir simulator with coupled phase behaviors and modeling of different mechanisms pertaining to thermal and chemical recovery methods. Development and implementation of a four-phase thermal-chemical reservoir simulator is quite important in the study as well as the evaluation of an individual or hybrid EOR methods. In this dissertation, a mathematical formulation of multi (pseudo) component, four-phase fluid flow in porous media is developed for mass conservation equation. Subsequently, a new volume balance equation is obtained for pressure of compressible real mixtures. Hence, the pressure equation is derived by extending a black oil model to a pseudo-compositional model for a wide range of components (water, oil, surfactant, polymer, anion, cation, alcohol, and gas). Mass balance equations are then solved for each component in order to compute volumetric concentrations. In this formulation, we consider interphase mass transfer between oil and gas (steam and water) as well as microemulsion and gas (microemulsion and steam). These formulations are derived at reservoir conditions. These new formulations are a set of coupled, nonlinear partial differential equations. The equations are approximated by finite difference methods implemented in a chemical flooding reservoir simulator (UTCHEM), which was a three-phase slightly compressible simulator, using an implicit pressure and an explicit concentration method. In our flow model, a comprehensive phase behavior is required for considering interphase mass transfer and phase tracking. Therefore, a four-phase behavior model is developed for gas (or steam)/ oil/water /microemulsion coexisting at equilibrium. This model represents coupling of the solution gas or steam table methods with Hand’s rule. Hand’s rule is used to capture the equilibrium between surfactant, oil, and water components as a function of salinity and concentrations for oil/water/microemulsion phases. Therefore, interphase mass transfer between gas/oil or steam/water in the presence of the microemulsion phase and the equilibrium between phases are calculated accurately. In this research, the conservation of energy equation is derived from the first law of thermodynamics based on a few assumptions and simplifications for a four-phase fluid flow model. This energy balance equation considers latent heat effect in solving for temperature due to phase change between water and steam. Accordingly, this equation is linearized and then a sequential implicit scheme is used for calculation of temperature. We also implemented the electrical Joule-heating process, where a heavy oil reservoir is heated in-situ by dissipation of electrical energy to reduce the viscosity of oil. In order to model the electrical Joule-heating in the presence of a four-phase fluid flow, Maxwell classical electromagnetism equations are used in this development. The equations are simplified and assumed for low frequency electric field to obtain the conservation of electrical current equation and the Ohm's law. The conservation of electrical current and the Ohm's law are implemented using a finite difference method in a four-phase chemical flooding reservoir simulator (UTCHEM). The Joule heating rate due to dissipation of electrical energy is calculated and added to the energy equation as a source term. Finally, we applied the developed model for solving different case studies. Our simulation results reveal that our models can accurately and successfully model the hybrid thermal chemical processes in comparison to existing models and simulators. / text

Made available in DSpace on 2014-12-17T14:08:37Z (GMT). No. of bitstreams: 1 ErnestoVBa_DISSERT.pdf: 9825397 bytes, checksum: 732b67b111fb317d406c771240e47d87 (MD5) Previous issue date: 2009-12-18 / Electrical resistive heating (ERH) is a thermal method used to improve oil recovery. It can increase oil rate and oil recovery due to temperature increase caused by electrical current passage through oil zone. ERH has some advantage compared with well-known thermal methods such as continuous steam flood, presenting low-water production. This method can be applied to reservoirs with different characteristics and initial reservoir conditions. Commercial software was used to test several cases using a semi-synthetic homogeneous reservoir with some characteristics as found in northeast Brazilian basins. It was realized a sensitivity analysis of some reservoir parameters, such as: oil zone, aquifer presence, gas cap presence and oil saturation on oil recovery and energy consumption. Then it was tested several cases studying the electrical variables considered more important in the process, such as: voltage, electrical configurations and electrodes positions. Energy optimization by electrodes voltage levels changes and electrical settings modify the intensity and the electrical current distribution in oil zone and, consequently, their influences in reservoir temperature reached at some regions. Results show which reservoir parameters were significant in order to improve oil recovery and energy requirement in for each reservoir. Most significant parameters on oil recovery and electrical energy delivered were oil thickness, presence of aquifer, presence of gas cap, voltage, electrical configuration and electrodes positions. Factors such as: connate water, water salinity and relative permeability to water at irreducible oil saturation had low influence on oil recovery but had some influence in energy requirements. It was possible to optimize energy consumption and oil recovery by electrical variables. Energy requirements can decrease by changing electrodes voltages during the process. This application can be extended to heavy oil reservoirs of high depth, such as offshore fields, where nowadays it is not applicable any conventional thermal process such as steam flooding / O Aquecimento El?trico Resistivo (AER) ? um m?todo t?rmico usado para aumentar a recupera??o de petr?leo. Este aumenta a vaz?o de ?leo e conseq?entemente a recupera??o de petr?leo devido ao aumento de temperatura promovida pela passagem de corrente el?trica na zona de interesse. O AER tem algumas vantagens sobre m?todos t?rmicos conhecidos, como inje??o cont?nua de vapor, por apresentar baixa produ??o de ?gua, podendo ser aplicado a reservat?rios com diversas caracter?sticas e diversas condi??es iniciais. Um software comercial foi usado para testar v?rios casos usando um reservat?rio homog?neo semi-sint?tico com algumas caracter?sticas encontradas em reservat?rio da bacia sedimentar do Nordeste Brasileiro. Foi realizada uma an?lise de sensibilidade dos par?metros de reservat?rio, tais como: espessura da zona de ?leo, presen?as de capa de g?s e de aq??fero e satura??o de ?leo, na recupera??o de ?leo e consumo de energia el?trica. V?rios casos foram testados usando vari?veis el?tricas consideradas mais importantes no processo, tais como: tens?o, configura??es el?tricas e posi??es dos eletrodos. Os resultados mostram que os par?metros de reservat?rio foram significativos no sentido de aumentar a recupera??o de ?leo e a demanda de energia em cada reservat?rio. Os par?metros mais significativos na recupera??o de ?leo e no consumo de energia foram: a espessura da zona de ?leo, presen?as de capa de g?s e de aq??fero, as configura??es el?tricas e a posi??o dos eletrodos. Fatores como: satura??o irredut?vel de ?gua, salinidade da ?gua e a permeabilidade relativa da ?gua na satura??o residual de ?leo tiveram pouca influ?ncia na recupera??o de ?leo, mas tiveram uma influ?ncia maior na demanda de energia. Foi poss?vel otimizar o consumo de energia com a recupera??o de ?leo usando as vari?veis el?tricas. Estas aplica??es podem ser estendidas para reservat?rios de ?leo pesado e de grande profundidade, como em campos mar?timos (offshore), onde atualmente n?o ? poss?vel o uso de m?todos t?rmicos convencionais de recupera??o, como a inje??o de vapor

Made available in DSpace on 2015-03-26T13:51:46Z (GMT). No. of bitstreams: 1 01 - capa_abstract.pdf: 113068 bytes, checksum: ac8d58045328d0ccbe13706fe9c3dede (MD5) Previous issue date: 2008-09-12 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The heavy oil (10 20ºAPI) is more than half of world oil reserves, there are predictions that in 2025 are the main source of oil in the world. The difficulties in exploration this kind of oil are associated with unfavorable characteristics such as density and viscosity (100 to 10.000 cP). With the need to improve the utilization of reservoir - in view of the relatively low levels of efficiency of traditional techniques - it has expanded the research to develop new techniques for recovery, especially Microbialy Enhanced Oil Recovery (MEOR). In the recovery of oil contained in sand-pack columns, two dimensionless variables are reported as important: the capillary number and ratio of viscosity. As the increases capillary number, the residual oil decreases. This can be achieved by reducing the interfacial tension between the fluid of residual oil. Several authors have reported the tensions interfaciais ultra between biosurfactant and hydrocarbons, including heavy oil. In the present work, tested the hypothesis that the biosurfactant produced on condition of reservoir, by two isolates of Bacillus subtilis from the collection of culture of the Laboratório de Biotecnologia e Biodiversidade para o Meio Ambiente (LBBMA / DMB / UFV), are capable to remove heavy oil in sand-pack columns. Initially, the isolates of Bacillus subtilis LBBMA 155 and Bacillus subtilis subsp. spizizenii LBBMA 258 were evaluated as to the growth and biosurfactant production in response to temperature and salinity. A central composite rotatable design (CCRD) was used, with temperature and salinity being independent variable. The results were analyzed using Response Surface Methodology (RSM) and showed that the those isolates were able of growth and biosurfactant production of under anaerobic conditions. The growth was influenced by temperature and biosurfactant production was influenced by temperature and salinity. After that, the biosurfactant produced by those isolates, alone or mixed, were analyzed as the ability to remove heavy oil trapped in sand-pack columms. The injection of three volumes of porous extract biossurfactante (EB) produced by Bacillus subtilis LBBMA 155 and Bacillus subtilis subsp. spizizenii LBBMA 258 removed 13.55% and 17.42%, respectively, from residual oil (14 ºAPI). The mixed of extracts from biosurfactant produced by those two isolates showed intermediate values of DMC and recovery of residual oil reported for each. Summarize, the extracts from biosurfactant (EB) produced under anaerobic conditions by Bacillus subtilis LBBMA 155 e Bacillus subtilis subsp. spizizenii LBBM 258 are effective in recovery heavy oil nuclei of the sand-pack columms and have potencial for use Microbialy Enhanced Oil Recovery. / Os óleos pesados (10-20 ºAPI) constituem mais da metade das reservas mundiais de petróleo, havendo previsões de que em 2025 sejam a principal fonte de petróleo no mundo. As dificuldades na exploração desse tipo de óleo estão associadas a características desfavoráveis, como densidade e viscosidade (100 a 10000 cP). Com a necessidade de melhorar o aproveitamento dos reservatórios tendo em vista os níveis relativamente baixos de eficiência das técnicas tradicionais tem-se ampliado as pesquisas para o desenvolvimento de novas técnicas de recuperação, destacando-se a recuperação avançada de petróleo melhorada por microrganismos (Microbially enhanced oil recovery MEOR). Na recuperação de óleos contidos em meios porosos, duas variáveis adimensionais são relatadas como importantes: o número capilar e a razão de viscosidade. À medida que o número capilar aumenta, o óleo residual decresce. Isso pode ser obtido por meio da redução da tensão interfacial entre o fluido de arraste e o óleo residual. Diversos autores têm reportado a obtenção de tensões interfaciais ultrabaixas entre biossurfactantes e hidrocarbonetos, incluindo o óleo pesado. Neste trabalho, testou-se a hipótese de que os biossurfactantes produzidos, em condição de reservatório, por dois isolados de Bacillus subtilis pertencentes à Coleção de Culturas do Laboratório de Biotecnologia e Biodiversidade para o Meio Ambiente (LBBMA/DMB/UFV), são capazes de mobilizar óleo pesado em sistemas porosos de areia. Inicialmente, os isolados de Bacillus subtilis LBBMA 155 e BacilIus subtilis spizizenii LBBMA 258 foram avaliados quanto ao crescimento e produção de biossurfactante em resposta a variações de temperatura e salinidade. Para tanto, foi empregada a Metodologia de Superfície de Resposta (MSR) através do delineamento experimental Composto Central Rotacional (DCCR), e observou-se que esses isolados foram capazes de produzir biossurfactantes em anaerobiose, sendo o crescimento influenciado pela temperatura e a produção de biossurfactante influenciada pela temperatura e pela salinidade. Posteriormente, os biossurfactantes produzidos por esses isolados, sozinhos ou em misturas, foram avaliados quanto à capacidade de mobilização de óleo pesado retido em núcleos porosos de areia. A injeção de três volumes porosos do extrato de biossurfactante (EB) produzidos por Bacillus subtilis LBBMA 155 e Bacillus subtilis subsp. spizizenii LBBMA 258 removeram 13,55% e 17,42%, respectivamente, de petróleo residual (14 ºAPI). A mistura dos extratos de biossurfactantes produzidos por esses dois isolados mostrou valores intermediários de DMC e recuperação de petróleo residual reportados para cada um. Sinteticamente, os extratos de biossurfactantes (EB) produzidos em anaerobiose por B. subtilis LBBMA 155 e B. subtilis subsp. spizizenii LBBMA 258 são efetivos na mobilização de óleo pesado em núcleos porosos de areia e possuem potencial de utilização na recuperação avançada de petróleo melhorada por microrganismos.

Made available in DSpace on 2014-12-17T14:08:51Z (GMT). No. of bitstreams: 1 RutinaldoAN_DISSERT.pdf: 3892841 bytes, checksum: c2e0ab636612eb7f303f7c05dcbc863a (MD5) Previous issue date: 2012-08-28 / Como os recursos de hidrocarbonetos convencionais est?o se esgotando, a crescente demanda mundial por energia impulsiona a ind?stria do petr?leo para desenvolver mais reservat?rios n?o convencionais. Os recursos mundiais de betume e ?leo pesado s?o estimados em 5,6 trilh?es de barris, dos quais 80% est?o localizados na Venezuela, Canad? e EUA. Um dos m?todos para explorar estes hidrocarbonetos ? o processo de drenagem gravitacional assistido com inje??o de vapor e solvente (ES-SAGD Expanding Solvent Steam Assisted Gravity Drainage). Neste processo s?o utilizados dois po?os horizontais paralelos e situados verticalmente um acima do outro, um produtor na base do reservat?rio e um injetor de vapor e solvente no topo do reservat?rio. Este processo ? composto por um m?todo t?rmico (inje??o de vapor) e um m?todo misc?vel (inje??o de solvente) com a finalidade de causar a redu??o das tens?es interfaciais e da viscosidade do ?leo ou betume. O objetivo deste estudo ? analisar a sensibilidade de alguns par?metros operacionais, tais como: tipo de solvente injetado, qualidade do vapor, dist?ncia vertical entre os po?os, porcentagem de solvente injetado e vaz?o de inje??o de vapor sobre o fator de recupera??o para 5, 10 e 15 anos. Os estudos foram realizados atrav?s de simula??es concretizadas no m?dulo STARS (Steam Thermal, and Advanced Processes Reservoir Simulator) do programa da CMG (Computer Modelling Group), vers?o 2010.10, onde as intera??es entre os par?metros operacionais, estudados em um modelo homog?neo com caracter?sticas de reservat?rios semelhantes aos encontrados no Nordeste Brasileiro, foram observadas. Os resultados obtidos neste estudo mostraram que os melhores fatores de recupera??o ocorreram para n?veis m?ximos do percentual de solvente injetado e da dist?ncia vertical entre os po?os. Observou-se tamb?m que o processo ser? rent?vel dependendo do tipo e do valor do solvente injetado

Made available in DSpace on 2014-12-17T15:01:22Z (GMT). No. of bitstreams: 1 GertrudesOQ.pdf: 1545154 bytes, checksum: 8733f5db29d9ddd6780de7e34160f375 (MD5) Previous issue date: 2005-12-16 / Thermal methods made heavy oil production possible in fields where primary recovery failed. Throughout the years steam injection became one of the most important alternatives to increase heavy oil recovery. There are many types of steam injection, and one of them is the cyclic steam injection, which has been used with success in several countries, including Brazil. The process involves three phases: firstly, steam is injected, inside of the producing well; secondly, the well is closed (soak period); and finally, the well is put back into production. These steps constitute one cycle. The cycle is repeated several times until economical production limit is reached. Usually, independent of reservoir type, as the number of cycles increases the cyclic injection turns less efficient. This work aims to analyze rock and reservoir property influence in the cyclic steam injection. The objective was to study the ideal number of cycles and, consequently, process optimization. Simulations were realized using the STARS simulator from the CMG group based in a proposed reservoir model. It was observed that the reservoir thickness was the most important parameter in the process performance, whilst soaking time influence was not significant / Os m?todos t?rmicos viabilizaram a produ??o de ?leo pesado em campos considerados n?o comerciais pelos m?todos convencionais de recupera??o. A inje??o de vapor, em particular, veio a se consagrar ao longo dos anos e ? hoje uma das principais alternativas economicamente vi?vel para o aumento da recupera??o dos ?leos pesados. Dentre as ramifica??es da inje??o de vapor existentes a inje??o c?clica tem sido utilizada com sucesso em escalas comerciais em v?rios pa?ses, incluindo o Brasil. O processo envolve tr?s fases: a primeira ? a inje??o de vapor na qual o vapor ? injetado, dentro do po?o produtor, por um per?odo espec?fico de tempo; em seguida, o po?o ? fechado por um curto per?odo de tempo ( soak period ); e finalmente, o po?o ? recolocado em produ??o durante meses a anos. Esse processo constitui um ciclo. O ciclo ? repetido um n?mero de vezes at? que o limite econ?mico na produ??o seja alcan?ado. Independente do tipo de reservat?rio, a inje??o c?clica geralmente se torna menos eficiente ? propor??o que o n?mero de ciclos aumenta. Este trabalho visa analisar a influ?ncia de algumas propriedades de rocha e reservat?rio na inje??o c?clica de vapor a fim de estudar o n?mero ideal de ciclos e, conseq?entemente, otimizar o processo. Foram realizadas simula??es, utilizando o simulador STARS do grupo CMG, a partir de um modelo de reservat?rio proposto. Observou-se que o efeito da espessura do reservat?rio foi o par?metro que mais influenciou no desempenho do processo, enquanto que para o tempo de soaking essa influ?ncia n?o foi significativa

La sécurité des procédés est une préoccupation majeure dans l'industrie du raffinage et de pétrochimie. Pour les procédés très exothermiques, l'emballement thermique doit être évité. Ainsi, l'objectif de la thèse est la mise en place d'une méthodologie d'étude de la stabilité thermique dans les réacteurs chimiques qui permet de déterminer les zones opératoires de fonctionnement stable du réacteur. Après le développement d'un modèle dynamique de réacteur, la méthodologie consiste à cartographier les zones de stabilité et d'instabilité du système réactionnel en régime stationnaire et dynamique. Le critère de Van Heerden (régime stationnaire) à été généralisé pour application à des systèmes réactionnels complexes. La méthode de perturbation des états stationnaires (régime dynamique) a aussi été intégrée à la méthodologie avec l'analyse des valeurs propres.Cette méthodologie a été appliquée au procédé d'hydroconversion en lit bouillonnant de charges pétrolières lourdes, ceci à l'échelle pilote et industrielle. Des modèles dynamiques adaptés au procédé pilote et industriel ont été développés. Ils tiennent en compte la complexité de la charge ainsi que le schéma des deux procédés. L'étude de la stabilité stationnaire et dynamique a été réalisée. Des cartographies de stabilité/instabilité en fonction des principaux paramètres du procédé ont été tracées. D'après les résultats obtenus, la plage stable pour réacteur pilote est plus large que pour le réacteur industriel. La variation des paramètres du procédé ont le même effet sur les deux réacteurs. Les cartographies de stabilité obtenues sont un outil indispensable pour l'ingénieur lors du design des procédés ou leur opération. / In refining and petrochemistry process safety is a major issue. For highly exothermic processes it is necessary to ensure in a rigorous way the safe that the process operates in safe conditions, hence avoiding thermal runaway. The objective of this thesis was to develop a methodology to determine the operating conditions of reliable operation of chemical reactors. The methodology relies on stationary and dynamic analysis. The stationary stability analysis based on the Van Heerden criterion was generalized to complex chemical systems. The dynamic analysis applies the perturbation theory to definitely determine if a stationary point is stable according to eigenvalue analysis.The methodology was applied to ebullated-bed technology for residue hydroconversion at pilot and industrial scale. Two comprehensive dynamic models that accurately represent the ebullated-bed pilot plant and industrial process were developed for the study. The models take into account a detailed description of the reactive system and the configuration of the pilot and industrial plants: three phases, kinetics and flow characterization. A stationary and dynamic thermal stability analysis was carried out for both configurations and stable/unstable operating regions were identified. The study showed that the pilot plant reactor can operate in a larger domain of operating conditions compared to the industrial reactor while the parameters have the same effect on both reactors. The resulting reactor operation diagrams are a essential guide for engineers in the reactor design and operation practice.

Les calculs d'équilibres à triphasiques et quadriphasiques sont au cœur des simulations de réservoirs impliquant des processus de récupérations tertiaires. Dans les procédés d'injection de gaz ou de vapeur, le système huile-gaz est enrichi d'une nouvelle phase qui joue un rôle important dans la récupération de l'huile en place. Les calculs d'équilibres représentent la majeure partie des temps de calculs dans les simulations de réservoir compositionnelles où les routines thermodynamiques sont appelées un nombre conséquent de fois. Il est donc important de concevoir des algorithmes qui soient fiables, robustes et rapides. Dans la littérature peu de simulateurs basés sur des équations d'état sont applicables aux procédés de récupération thermique. A notre connaissance, il n'existe pas de simulation thermique complètement compositionnelle de ces procédés pour des cas d'applications aux huiles lourdes. Ces simulations apparaissent essentielles et pourraient offrir des outils améliorés pour l’étude prédictive de certains champs. Dans cette thèse, des algorithmes robustes et efficaces de calculs d’équilibre multiphasiques sont proposés permettant de surmonter les difficultés rencontrés durant les simulations d'injection de vapeur pour des huiles lourdes. La plupart des algorithmes d'équilibre de phases sont basés sur la méthode de Newton et utilisent les variables conventionnelles comme variables indépendantes. Dans un premier temps, des améliorations de ces algorithmes sont proposées. Les variables réduites permettent de réduire la dimensionnalité du système de nc (nombre de composants) dans le cas des variables conventionnelles, à M (M<<nc), et sont déjà utilisées dans certains simulateurs de réservoirs commerciaux. La méthode de réduction proposée par Nichita and Graciaa (Fluid Phase Equil. 302 (2011) 226-233) est étendue à l'analyse de stabilité et aux calculs d'équilibres multiphasiques. A l'inverse des précédentes méthodes de réduction, les variables ne sont pas bornées. La méthode de Newton nécessite une Hessienne définie positive pour pouvoir être utilisée. D'autres méthodes de minimisations sont testées permettant de s'affranchir de cette contrainte; les méthodes Quasi-Newton et Trust-Region qui garantissent une direction de descente à chaque itération. Ces dernières présentent un grand intérêt puisqu'elles permettent de réaliser des pas supra-linéaires (même lorsque la Hessienne n'est pas définie positive) et quadratiques (Trust-Region) ou proches de quadratiques (Quasi-Newton) dans le cas contraire. Un nouveau vecteur de variables indépendantes est proposé (construit afin d'obtenir une meilleure mise échelle du problème) et utilisé au sein d'un algorithme BFGS modifié. De même, une méthode de Trust-Region est développée pour les problèmes de tests de stabilités et d'équilibres multiphasiques. Ensuite, considérant le fluide comme semi-continu, une méthodologie basée sur une procédure de quadrature Gaussienne est proposée pour calculer mathématiquement les pseudo-composants capables de représenter le comportement du fluide. La méthodologie peut être vue comme une procédure de groupement/dégroupement, applicable pour tout nombre de points de quadratures et toute composition de mélange. Dans une dernière partie, un algorithme général pour le calcul d’équilibre multiphasique est présenté incluant tous les algorithmes développés. Ce dernier est testé et validé contre des données expérimentales et de la littérature. Des simulations triphasiques et quadriphasiques d'injection de CO2 démontrent la capacité du programme à traiter un nombre arbitraire de phases. Des simulations de balayages par la vapeur sont réalisées pour des réservoirs montrant d'importantes hétérogénéités. Finalement, une simulation complètement compositionnelle du processus de Steam Assisted Gravity Drainage est réalisée. A notre connaissance, il s'agit de la première simulation de la sorte pour des cas d'applications d'huiles lourdes. / Three to four phase equilibrium calculations are in the heart of tertiary recovery simulations. In gas/steam injection processes, additional phases emerging from the oil-gas system are added to the set and have a significant impact on the oil recovery. The most important computational effort in many chemical process simulators and in petroleum compositional reservoir simulations is required by phase equilibrium and thermodynamic property calculations. In field scale reservoir simulations, a huge number of phase equilibrium calculations is required. For all these reasons, the algorithms must be robust and time-saving. In the literature, few simulators based on equations of state (EoS) are applicable to thermal recovery processes such as steam injection. To the best of our knowledge, no fully compositional thermal simulation of the steam injection process has been proposed with extra-heavy oils; these simulations are essential and will offer improved tools for predictive studies of the heavy oil fields. Thus, in this thesis different algorithms of improved efficiency and robustness for multiphase equilibrium calculations are proposed, able to handle conditions encountered during the simulation of steam injection for heavy oil mixtures. Most of the phase equilibrium calculations are based on the Newton method and use conventional independent variables. These algorithms are first investigated and different improvements are proposed. Michelsen’s (Fluid Phase Equil. 9 (1982) 21-40) method for multiphase-split problems is modified to take full advantage of symmetry (in the construction of the Jacobian matrix and the resolution of the linear system). The reduction methods enable to reduce the space of study from nc (number of components) for conventional variables to M (M<<nc) and are already used in some commercial reservoir simulators. The reduction method proposed by Nichita and Graciaa (Fluid Phase Equil. 302 (2011) 226-233) is extended to phase stability analysis and multiphase-split calculations. Unlike previous reduction methods, the set of variables is unbounded and the convergence path is the same as in conventional methods using the logarithm of equilibrium constants as variables. The Newton method requires a positive definite Hessian for convergence. Other kinds of minimization methods are investigated which overcome this constraint; the Quasi-Newton and Trust-region methods always guarantee a descent direction. These methods represent an interesting alternative since they can reach supra-linear steps even when the Hessian is non-positive definite, and can reach quadratic steps (Trust-Region) or nearly quadratic steps (Quasi-Newton) otherwise. A new set of independent variables is proposed (designed to ensure a better scaling of the problem) for a modified BFGS (which ensures the positive definiteness of the approximation of the Hessian matrix) algorithm and a Trust-Region method is also proposed for the stability-testing and phase-split problems. Subsequently, by assuming the fluid composition as semi-continuous, a methodology based on a Gaussian quadrature is proposed to mathematically compute a set of pseudo-components capable of representing the fluid behavior. The methodology can be seen as a lumping-delumping procedure, applicable to any number of quadrature points and to any feed distribution. In a last part, a general multiphase flash procedure implementing all the developed algorithms is presented, and tested against experimental and literature data. Three- and four phase CO2 injection simulations demonstrate the capability of the program to handle any number of phases. Simulations of steam flooding are performed for highly heterogeneous reservoirs. Finally, a fully compositional simulation of the steam assisted gravity drainage process is realized. To the best of our knowledge, this is the first simulation of the kind for heavy oil mixtures.