High oil-viscosity is a major concern for the recovery of oil from heavy-oil reservoirs. Introducing energy to the formation has proven to be an effective way of lowering the oil viscosity by raising the temperature in the formation. The application of low-frequency heating, also known as electrical resistance heating, is limited by water vaporization near the wellbore which breaks the conductive path to the reservoir, and limits the heating rate as well as the resulting production rates. Electromagnetic (EM) heating, also called high-frequency heating, can be used instead. Although its potential was recognized during the late 70’s, no simulation results or detailed modeling studies have yet been published that completely model the complex interactions of EM energy and multiphase flow. One of the main drawbacks of proposed models is the use of the EM adsorption coefficient as a constant regardless of the properties of the medium, which can obscure the important effect of this parameter on the extension of the reservoir area heated. This dissertation presents a multiphase, two-dimensional radial model that describes the three-phase flow of water, oil, and steam and heat flow in a reservoir within confining conductive formations. The model accounts for the appearance and/or disappearance of a phase, and uses the variation in temperature and water saturation to update the EM absorption coefficient. This model allows determining the temperature distribution and the productivity improvement from EM heating when multiple phases are present. For the numerical simulations of EM heating, I used COMSOL Multiphysics, a Lagrange-quadratic finite element simulator, and its partial differential equations (PDE) application. Several simulations were made for hypothetical reservoirs with different fluid and rock properties. Also, analytical solutions for a single-phase EM heating model were developed and used to validate the numerical solutions. Special attention is focused on reservoirs with characteristics for which steam injection is not attractive or feasible such as low permeability, thin-zone, and extra-heavy oil reservoirs. Results showed that EM heating is feasible based on the power source and frequency used to maintain an optimum absorption coefficient and to obtain higher production rates. Comparisons showed that cumulative oil production and recovery factor obtained by EM heating are better than what is achieved by cyclic steam stimulation (CSS) for reservoirs with the above mentioned characteristics. / text

Steam assisted gravity drainage (SAGD) has been demonstrated as a proven technology to unlock heavy oil and bitumen in Canadian reservoirs. Given the large energy requirements and volumes of emitted greenhouse gases from SAGD processes, there is a strong motivation to develop enhanced oil recovery processes with lower energy and emission intensities. In this study, the addition of solvents to steam has been examined to reduce the energy intensity of the SAGD process. Higher oil recovery, accelerated oil production rate, reduced steam-to-oil ratio, and more favorable economics are expected from the addition of suitable hydrocarbon additives to steam. A systematic approach was used to develop an effective hybrid steam/solvent injection to improve the SAGD process. Initially, an extensive parametric simulation study was carried out to find the suitable hydrocarbon additives and injection strategies. Simulation studies aim to narrow down hybrid steam/solvent processes, design suitable solvent type and concentration, and explain the mechanism of solvent addition to steam. In the experimental phase, the most promising solvents (n-hexane and n-heptane) were used with different injection strategies. Steam and hydrocarbon additives were injected in continuous or alternating schemes. The results of the integrated experimental and simulation study were used to better understand the mechanism of hybrid steam/solvent processes. Experimental and simulation results show that solvent co-injection with steam leads to a process with higher oil production, better oil recovery, and less energy intensity with more favorable economy. Solvent choice for hybrid steam/solvent injection is not solely dependent on the mobility improvement capability of the solvents but also reservoir properties and operational conditions such as operating pressure and injection strategy. Pure heated solvent injection requires significant quantities. A vaporized solvent chamber is not sustainable due to low latent heat of the solvents. Alternating steam and solvent injection provides heat for the solvent cycles and increases oil recovery. Co-injection of small volumes (5-15% by volume) of suitable solvents at the early times of the SAGD operation considerably improves the economics of the SAGD process.

A new combustion zone analytical model has been developed in which the combustion front temperature may be calculated. The model describes in the combustion zone, the amount of fuel burned based on reaction kinetics, the fuel concentration and produced gas composition based on combustion stoichiometry, and the amount of heat generated based on a heat balance. Six runs were performed in a 3-inch diameter, 40-inch long steel combustion tube with Jobo crude oil (9-11°API) from the Orinoco Belt in Venezuela. These runs were carried out with air containing three values of oxygen concentration, 21%, 30%, and 40%. The weight percentage of sand, clay, water, and oil in the sand mix was kept constant in all runs at 86.6%, 4.7%, 4.0%, and 4.7% respectively. Injection air rates (3 L/min) as well as the production pressure (300 psig) were kept constant in all runs. The results indicate that the calculated combustion zone temperatures and temperature profiles are in good agreement with the experimental data, for the range of oxygen concentration in the injected air. The use of oxygen-enriched air slightly increased the combustion front temperature from 440°C in a 21 mole % O2 concentration to a maximum of 475°C for air with 40 mole % O2 concentration. Oxygen-enriched air injection also increased the combustion front velocity from 13.4 cm/hr (for 21% oxygen) to 24.7 cm/hr (for 40% oxygen), thus reducing the start of oil production from 3.3 hours (for 21% oxygen) to 1.8 hours (for 40% oxygen). In the field, the use of oxygen-enriched air injection could translate into earlier oil production compared to with not-enriched air injection. The new analytical model for the combustion zone developed in this study will be beneficial to future researchers in understanding the effect of oxygen-enriched in-situ combustion and its implications on the combustion front temperature and combustion front thickness.

No description available.

Orientador: Osvair Vidal Trevisan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-18T05:54:25Z (GMT). No. of bitstreams: 1 Rios_VictordeSouza_M.pdf: 7274961 bytes, checksum: badfe10558862e259afaf6310ddae8f6 (MD5) Previous issue date: 2011 / Resumo: Os métodos térmicos de recuperação viabilizaram a produção de óleo pesado em campos considerados não comerciais pelos métodos convencionais de recuperação. A injeção de vapor, em particular, veio a se consagrar ao longo dos anos e é hoje uma das principais alternativas economicamente viáveis para o aumento da recuperação dos óleos pesados. Nesse contexto, destaca-se a drenagem gravitacional assistida por vapor, "Steam Assisted Gravity Drainage" (SAGD). Esse processo caracteriza-se por utilizar dois poços horizontais: um produtor, localizado próximo à base do reservatório e um injetor, situado alguns metros acima. O objetivo desse método é criar uma câmara de vapor, enquanto promove uma melhor varredura dos fluidos do reservatório. A razão do volume de vapor injetado por volume de óleo recuperado é um parâmetro decisivo na economicidade de projetos de injeção de vapor. No presente trabalho um estudo experimental do método SAGD foi desenvolvido para entender melhor o processo de drenagem gravitacional assistida por vapor na recuperação de óleo pesado. Aliando-se a isso, também foi investigada a injeção de nitrogênio combinado com vapor, o que contribui para o mecanismo de recuperação e para a redução em volume do vapor injetado, refletindo na economicidade do projeto. Simulações numéricas utilizando um software comercial foram realizadas visando a dar suporte às análises feitas. Os estudos foram conduzidos em escala de laboratório com óleo pesado da bacia do Espírito Santo. Os resultados obtidos mostram que a injeção de nitrogênio após certo período de injeção contínua de vapor, método conhecido como SAGD - Wind Down, reflete na redução considerável da razão vapor/óleo sem, no entanto, afetar de forma muito sensível a produção de óleo, quando comparado ao SAGD convencional / Abstract: Thermal recovery methods made possible the production of heavy oil fields considered non-commercial with conventional recovery methods. The steam injection, in particular, improved itself over the years and is now a major cost-effective alternative for increasing the heavy oil recovery. In this context, the Steam Assisted Gravity Drainage (SAGD) is the process that uses two horizontal wells with the steam injector above the producer which stays at the base of the reservoir. The purpose of this method is to create a steam chamber, while promoting a better sweep of the fluid reservoir. The steam oil ratio is a decisive parameter in the economic viability of projects with steamflooding. In this paper, an experimental study of a SAGD cell was developed to understand better the steam assisted gravity drainage on the heavy oil recovery. Allied to this, it was also investigated the nitrogen injection combined with steam, which contributes to the recovery mechanism and a possible reduction in volume of steam injected, reflecting on the economy of the project. The studies were conducted in laboratory scale with heavy oil from the Espírito Santo basin. The results show that injection of nitrogen after a period of steamflooding, a method known as SAGD - Wind Down, reflects the considerable reduction in the steam oil ratio without, however, affect significantly the oil production, when compared to conventional SAGD / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Orientador: Osvair Vidal Trevisan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica, Instituto de Geociencias / Made available in DSpace on 2018-08-12T16:27:35Z (GMT). No. of bitstreams: 1 Torres_DiegoMartins_M.pdf: 2427888 bytes, checksum: 01e4a5a345f2937373fd5e872ad573f7 (MD5) Previous issue date: 2008 / Resumo: A injeção de vapor é uma das técnicas mais utilizadas em todo o mundo para a recuperação de óleos pesados. O escopo do presente trabalho é o da proposição de uma bancada para estudos experimentais dessa técnica. A bancada é detalhada, dando-se ênfase aos seus principais componentes, tais como: gerador de vapor, controle do título do vapor e os protótipos de injeção, um tubo para estudo do processo de injeção contínua de vapor, e uma célula para estudo do processo de drenagem gravitacional assistida por vapor (SAGD - Steam Assisted Gravity Drainage). Baseados nos modelos experimentais, modelos numéricos são criados e realiza-se uma série de simulações para prever o comportamento dos modelos para diferentes valores de propriedades de rocha e de fluidos. Com as simulações buscou-se conhecer as faixas de parâmetros para o funcionamento da bancada, o comportamento das curvas de recuperação de óleo, os perfis de pressão e temperatura ao longo do tempo, estimar a saturação residual do óleo e prever a dinâmica da expansão da câmara de vapor dentro dos modelos de injeção. / Abstract: Steam injection is one of the most widely used techniques in the word for heavy oil recovery. The scope of this work refers to the proposition of an experimental apparatus for studying this technique. The apparatus is detailed, with emphasis on its major components, such as: steam generator, steam quality control and the injection prototypes: a tube to study the steam flooding process, and a cell to study the steam assisted gravity drainage (SAGD) method. Based on the experimental models, numerical models are created and a series of simulation runs is carried out to predict the models behavior for different values of rock and fluid properties. The simulation tests are useful to identify the parameters range for the proper functioning of apparatus, the oil production curves behavior, the pressure and temperature profiles over time, to estimate the residual oil saturation and to predict the steam chamber expansion dynamics inside the injection models. / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Thermal recovery methods are frequently used to enhance the production of heavy crude oils. Steam-based processes are the most economically popular and effective methods for heavy oil recovery for several decades. In general, there are various mechanisms over steam injection to enhance and have additional oil recovery. However, among these mechanisms, steam distillation plays pivotal role in the recovery of crude oil during thermal recovery process. In this study, an experimental investigation was carried out to investigate the role of various minerals present in both sandstone and carbonate formations as well as the effect of steam temperature on steam distillation process. Two different types of dead-heavy crude oils were tested in a batch autoclave reactor with 30 % water and the content of the reactor (crude oil, 10 % rock and mineral). The results were compared as the changes in the density, viscosity and chemical composition (SARA and TPH analyses) of heavy crude oil. Five different mineral types (bentonite, sepiolite, kaolinite, illite and zeolite) were added into the original crude oil and reservoir rocks to observe their effects on the rheological and compositional changes during steam distillation process. Analysis of the results of experiments with Camurlu and Bati Raman heavy crude oils in the presence of different minerals such as Bentonite, Zeolite, Illite, Sepiolite, and Kaolinite in both sandstone and limestone reservoir rocks indicate that steam distillation produces light end condensates which can be considered as solvent or condensate bank during steam flooding operation. It was also illustrated that minerals in reservoir formations perform the function of producing distilled light oil compounds, resulting in enhancement of heavy crude oils recovery in steam flooding. Measurements showed that the remaining oil after steam distillation has higher viscosity and density. On the other hand, the effect of steam distillation is more pronounced in limestone reservoirs compared to sandstone reservoirs for the given heavy crude oil and steam temperature. Among the five different minerals tested, kaolinite found to be the most effective mineral in terms of steam distillation.

A 16×16×5.6 in. scaled, three-dimensional, physical model of a quarter of a 9-spot pattern was constructed to study the application of two processes designed to improve the efficiency of steam injection. The first process to be tested is the use of propane as a steam additive with the purpose of increasing recovery and accelerating oil production. The second process involves the use of a novel production configuration that makes use of a vertical injector and a smart horizontal producer in an attempt to mitigate the effects of steam override. The experimental model was scaled using the conditions in the San Ardo field in California and crude oil from the same field was used for the tests. Superheated steam at 190 – 200ºC was injected at 48 cm3/min (cold water equivalent) while maintaining the flowing pressures in the production wells at 50 psig. Liquid samples from each producer in the model were collected and treated to break emulsion and analyzed to determine water and oil volumes. Two different production configurations were tested: (1) a vertical well system with a vertical injector and three vertical producers and (2) a vertical injector-smart horizontal well system that consisted of a vertical injector and a smart horizontal producer divided into three sections. Runs were conducted using pure steam injection and steam-propane injection in the two well configurations. Experimental results indicated the following. First, for the vertical configuration, the addition of propane accelerated oil production by 53% and increased ultimate recovery by an additional 7% of the original oil in place when compared to pure steam injection. Second, the implementation of the smart horizontal system increased ultimate oil recovery when compared to the recovery obtained by employing the conventional vertical well system (49% versus 42% of the OOIP).

Made available in DSpace on 2014-12-17T15:01:45Z (GMT). No. of bitstreams: 1 JennysLMB.pdf: 3002293 bytes, checksum: 3b71773a14bee418fd80243a633d0cc8 (MD5) Previous issue date: 2008-02-22 / Steam assisted gravity drainage process (SAGD) involves two parallel horizontal wells located in a same vertical plane, where the top well is used as steam injector and the bottom well as producer. The dominant force in this process is gravitational. This improved oil recovery method has been demonstrated to be economically viable in commercial projects of oil recovery for heavy and extra heavy oil, but it is not yet implemented in Brazil. The study of this technology in reservoirs with characteristics of regional basins is necessary in order to analyze if this process can be used, minimizing the steam rate demand and improving the process profitability. In this study, a homogeneous reservoir was modeled with characteristics of Brazilian Northeast reservoirs. Simulations were accomplished with STARS , a commercial software from Computer Modelling Group, which is used to simulate improved oil recovery process in oil reservoirs. In this work, a steam optimization was accomplished in reservoirs with different physical characteristics and in different cases, through a technical-economic analysis. It was also studied a semi-continuous steam injection or with injection stops. Results showed that it is possible to use a simplified equation of the net present value, which incorporates earnings and expenses on oil production and expenses in steam requirement, in order to optimize steam rate and obtaining a higher net present value in the process. It was observed that SAGD process can be or not profitable depending on reservoirs characteristics. It was also obtained that steam demand can still be reduced injecting in a non continuous form, alternating steam injection with stops at several time intervals. The optimization of these intervals allowed to minimize heat losses and to improve oil recovery / O processo de drenagem gravitacional com inje??o cont?nua de vapor (SAGD) envolve dois po?os horizontais paralelos localizados em uma mesma vertical, onde o po?o superior ? usado como injetor de vapor e o inferior como produtor. A for?a dominante neste processo ? a gravitacional. Este m?todo de recupera??o avan?ada tem sido demonstrado ser economicamente vi?vel em projetos comerciais de recupera??o de petr?leo pesado e extra pesado, mas ainda n?o foi implementado no Brasil. O estudo desta tecnologia em reservat?rios com caracter?sticas das bacias regionais ? necess?rio para analisar como se ad?qua o processo para minimizar a demanda de vapor obtendo a maior rentabilidade do processo. Neste estudo foi usado um modelo homog?neo com caracter?sticas de reservat?rios do Nordeste Brasileiro. As simula??es foram realizadas em um programa comercial da Computer Modelling Group , o STARS , m?dulo usado para realizar estudos de m?todos de recupera??o avan?ada de reservat?rios de ?leo. Neste trabalho, foi realizada uma otimiza??o do vapor em reservat?rios com diferentes caracter?sticas f?sicas e em diferentes cen?rios, atrav?s de uma an?lise t?cnico-econ?mica. Tamb?m foi estudada a inje??o de vapor semi-cont?nua ou com paradas. Os resultados obtidos mostraram que ? poss?vel utilizar uma equa??o simplificada do valor presente l?quido, que incorpora os ganhos e gastos na produ??o de ?leo e os gastos na inje??o de vapor, para otimizar a demanda do vapor obtendo um maior valor presente l?quido no processo. Observou-se que o m?todo (SAGD) pode ser ou n?o rent?vel dependendo das caracter?sticas do reservat?rio. Encontrou-se tamb?m que a necessidade de vapor pode ainda ser diminu?da utilizando esquemas de inje??o de vapor com paradas em intervalos de tempo otimizados, e isto permitiu minimizar as perdas de calor e melhorar a recupera??o.

Orientador: Osvair Vidal Trevisan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-17T03:24:53Z (GMT). No. of bitstreams: 1 Cruz_RafaelOscardeMoraes_M.pdf: 2702019 bytes, checksum: 2b9e5d6d733bae790360b90f575601e6 (MD5) Previous issue date: 2010 / Resumo: A previsão de comportamento de reservatórios submetidos a combustão in-situ é trabalhosa e empírica já que além das complexidades geológicas, é necessário modelar a complexidade do hidrocarboneto de reservatório e das reações químicas que ocorrem no processo. As etapas de projeto de campo costumam envolver 1) seleção de reservatório; 2) experimentos termo-analíticos; 3) experimentos em tubo de combustão; 4) aplicação de métodos analíticos; 5) simulação numérica; 6) calibração dos modelos analíticos e numéricos através de dados de projeto piloto. O escopo de trabalho desta dissertação está concentrado nas Etapas 4 e 5 deste processo e o foco é a previsão de comportamento de projetos de campo. Propõe-se uma metodologia de mudança de escala para tratamento de dados advindos de laboratório para uso em previsão de comportamento. Adapta-se um equacionamento clássico de projeto de campo de Nelson e Mcneil (1961) para agregar o conceito de velocidade mínima de frente de chama. Para avaliar a extensão dos resultados obtidos com os experimentos em células de combustão 3D de Coates et al (1995) e de Greaves e Turta (2003), que foram realizados para testar as configurações de poço top-down e thai respectivamente, realiza-se simulações em escala de laboratório para reproduzir uma célula de combustão 3D, e avalia-se o impacto de diversos parâmetros de modelagem, como a composição dos fluidos e as reações químicas, além de parâmetros operacionais. Nestas simulações foi possível reproduzir maior complexidade do modelo de fluidos e das reações químicas, incluindo reações de adição de oxigênio e de quebra de cadeia. Foi possível ainda reproduzir a dependência entre estas reações, fazendo com que o combustível para as reações de quebra de cadeia fosse gerado nas reações de adição de oxigênio. Utilizou-se uma malha tão refinada quanto as dimensões da frente de chama, de forma que se controlou a evolução das reações pela temperatura. Para exemplificar a metodologia proposta de mudança de escala e de projeto de campo, utilizou-se os experimentos em tubo de combustão de Gonçalves (2010). Os parâmetros projetados foram aplicados em simulações em escala de campo, onde a evolução das reações químicas foi controlada pela velocidade. Definiu-se uma velocidade mínima para avanço da frente de chama através de tratamento dos dados advindos dos experimentos em tubo de combustão e aplicou-se no modelo de simulação, onde se investigou a capacidade de previsão da evolução da frente de chama em um cenário com propriedades geológicas heterogêneas / Abstract: Behavior forecast of reservoirs subjected to in-situ combustion is hard and empirical since besides geological complexities it is necessary to reproduce complex fluid models and several chemical reactions that are part of the process. The work flow for field project usually involves: 1) reservoir screening; 2) thermo-analytical experiments; 3) combustion tube experiments; 4) use of analytical models; 5) numerical simulation and 6) fitting of analytical and numerical models with field pilot data. The present work concerns the fourth and fifth stages of this process and the focus is behavior forecast of field projects. A methodology for upscaling laboratory results for application in behavior forecast is proposed. The classical Nelson and Mcneil (1961) field project equations are adapted to account for the minimum velocity of the combustion front. In order to evaluate the extension of the results obtained by Coates et al (1995) and Greaves and Turta (2003) with 3D combustion cells, wich were carried to test the thai and top-down well configuration respectively, laboratory scale numerical simulation that reproduces a 3D combustion cell is conducted and the influence of several modeling parameters, such as fluid composition and chemical reactions, is tested, along with operational parameters. In this simulations, a greater complexity in the fluid and reaction model is possible with both oxygen addition and bond scission reactions. It is also possible to model the dependency between reactions, making the reactant of high temperature reactions to be formed in low temperature reactions. A grid refinement in the same size of the combustion front is used and chemical reactions continuity is controlled through temperature. Data from the combustion tube experiments from Gonçalves (2010) are used to exemplify and apply the upscaling and field project methodology. The obtained project parameters are used as input for field scale numerical simulation, where the chemical reactions continuity is controlled through velocity. A minimum combustion front velocity is defined and applied in the simulation model, where the capacity of forecast of the combustion front migration in an heterogeneous geological context is evaluated / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo