Made available in DSpace on 2014-06-12T17:42:05Z (GMT). No. of bitstreams: 2 arquivo6690_1.pdf: 810310 bytes, checksum: baf40fdb2f7b71498cac99021606330f (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2002 / Novos códigos para simulação de reservatórios de petróleo vêm sendo desenvolvidos para tratar problemas de larga escala usando processamento de alto desempenho. Este trabalho consiste no desenvolvimento de um simulador de reservatórios usando técnicas de programação para computadores paralelos com memória distribuída. É implementado o modelo Black-Oil bifásico óleo/água, cujas equações são discretizadas usando o método das diferenças nitas em malhas retangulares de blocos centrados. As equações discretas são linearizadas utilizando a formulação IMPES e a totalmente implícita. As não-linearidades são tratadas utilizando o método de Newton-Inexato, com ciclo interno - o sistema linear - resolvido por diversos métodos iterativos com diferentes precondicionadores. Para isto é utilizado o software PETSc, que utiliza o MPI para efetuar toda comunicação de dados entre processadores. Os resultados obtidos, comparados com os do simulador comercial BOAST-98, validam o modelo implementado. A análise de desempenho realizada em um computador paralelo, especi camente um cluster de PCs, apresenta e ciências bastante elevadas de até 97%, validando também a implementação do modelo de programação paralela

It has been known that volatile oil and gas condensate reservoirs cannot be modeled accurately with conventional black-oil models. One variation to the black-oil approach is the modified black-oil (MBO) model that allows the use of a simple, and less expensive computational algorithm than a fully compositional model that can result in significant timesaving in full field studies. The MBO model was tested against the fully compositional model and performances of both models were compared using various production and injection scenarios for a rich gas condensate reservoir. The software used to perform the compositional and MBO runs were Eclipse 300 and Eclipse 100 versions 2002A. The effects of black-oil PVT table generation methods, uniform composition and compositional gradient with depth, initialization methods, location of the completions, production and injection rates, kv/kh ratios on the performance of the MBO model were investigated. Vertical wells and horizontal wells with different drain hole lengths were used. Contrary to the common belief that oil-gas ratio versus depth initialization gives better representation of original fluids in place, initializations with saturation pressure versus depth gave closer original fluids in place considering the true initial fluids in place are given by the fully compositional model initialized with compositional gradient. Compared to the compositional model, results showed that initially there was a discrepancy in saturation pressures with depth in the MBO model whether it was initialized with solution gas-oil ratio (GOR) and oil-gas ratio (OGR) or dew point pressure versus depth tables. In the MBO model this discrepancy resulted in earlier condensation and lower oil production rates than compositional model at the beginning of the simulation. Unrealistic vaporization in the MBO model was encountered in both natural depletion and cycling cases. Oil saturation profiles illustrated the differences in condensate saturation distribution for the near wellbore area and the entire reservoir even though the production performance of the models was in good agreement. The MBO model representation of compositional phenomena for a gas condensate reservoir proved to be successful in the following cases: full pressure maintenance, reduced vertical communication, vertical well with upper completions, and producer set as a horizontal well.

It has been known that volatile oil and gas condensate reservoirs cannot be modeled accurately with conventional black-oil models. One variation to the black-oil approach is the modified black-oil (MBO) model that allows the use of a simple, and less expensive computational algorithm than a fully compositional model that can result in significant timesaving in full field studies. The MBO model was tested against the fully compositional model and performances of both models were compared using various production and injection scenarios for a rich gas condensate reservoir. The software used to perform the compositional and MBO runs were Eclipse 300 and Eclipse 100 versions 2002A. The effects of black-oil PVT table generation methods, uniform composition and compositional gradient with depth, initialization methods, location of the completions, production and injection rates, kv/kh ratios on the performance of the MBO model were investigated. Vertical wells and horizontal wells with different drain hole lengths were used. Contrary to the common belief that oil-gas ratio versus depth initialization gives better representation of original fluids in place, initializations with saturation pressure versus depth gave closer original fluids in place considering the true initial fluids in place are given by the fully compositional model initialized with compositional gradient. Compared to the compositional model, results showed that initially there was a discrepancy in saturation pressures with depth in the MBO model whether it was initialized with solution gas-oil ratio (GOR) and oil-gas ratio (OGR) or dew point pressure versus depth tables. In the MBO model this discrepancy resulted in earlier condensation and lower oil production rates than compositional model at the beginning of the simulation. Unrealistic vaporization in the MBO model was encountered in both natural depletion and cycling cases. Oil saturation profiles illustrated the differences in condensate saturation distribution for the near wellbore area and the entire reservoir even though the production performance of the models was in good agreement. The MBO model representation of compositional phenomena for a gas condensate reservoir proved to be successful in the following cases: full pressure maintenance, reduced vertical communication, vertical well with upper completions, and producer set as a horizontal well.

Um modelo matemático e simulações numéricas são apresentados para investigação da dinâmica do escoamento de gás, óleo e água em sistemas pipeline-riser. O pipeline é modelado como um sistema de parâmetros concentrados e considera dois estados comutáveis: um em que o gás é capaz de penetrar no riser e outro no qual há uma frente de acúmulo de líquido, prevenindo a penetração do gás. O modelo do riser considera um sistema de parâmetros distribuídos, no qual nós móveis são usados para avaliar as condições locais ao longo do subsistema. Efeitos de transferência de massa são modelados utilizando a aproximação de black-oil. O modelo prediz a localização da frente de acúmulo de líquido no pipeline e do nível de líquido no riser, de maneira que é possível determinar qual tipo de intermitência severa ocorre no sistema. O método das características é usado para simplificar a diferenciação no sistema de equações mistas hiperbólicas-parabólicas resultante. As equações são discretizadas e integradas usando um método implícito com um esquema preditor-corretor para o tratamento das não-linearidades. Simulações correspondentes às condições de intermitência severa são apresentadas e comparadas aos resultados obtidos com o código computacional OLGA, resultando em uma boa concordância. Apresenta-se uma descrição dos tipos de intermitência severa para o escoamento trifásico de gás, óleo e água em um sistema pipeline-riser com efeitos de transferência de massa, assim como um estudo da influência de parâmetros geométricos e de caracterização dos fluidos sobre os mapas de estabilidade. / A mathematical model and numerical simulations are presented to investigate the dynamics of gas, oil and water flow in a pipeline-riser system. The pipeline is modeled as a lumped parameter system and considers two switchable states: one in which the gas is able to penetrate into the riser and another in which there is a liquid accumulation front, preventing the gas from penetrating the riser. The riser model considers a distributed parameter system, in which movable nodes are used to evaluate local conditions along the subsystem. Mass transfer effects are modeled by using a black oil approximation. The model predicts the location of the liquid accumulation front in the pipeline and the liquid level in the riser, so it is possible to determine which type of severe slugging occurs in the system. The method of characteristics is used to simplify the differentiation of the resulting mixed hyperbolic-parabolic system of equations. The equations are discretized and integrated using an implicit method with a predictor-corrector scheme for the treatment of the nonlinearities. Simulations corresponding to severe slugging conditions are presented and compared to results obtained with OLGA computer code, showing a very good agreement. A description of the types of severe slugging for the three-phase flow of gas, oil and water in a pipeline-riser system with mass transfer effects is presented, as well as a study of the influence of geometric and fluid characterization parameters on the stability maps.

Um modelo matemático e simulações numéricas são apresentados para investigação da dinâmica do escoamento de gás, óleo e água em sistemas pipeline-riser. O pipeline é modelado como um sistema de parâmetros concentrados e considera dois estados comutáveis: um em que o gás é capaz de penetrar no riser e outro no qual há uma frente de acúmulo de líquido, prevenindo a penetração do gás. O modelo do riser considera um sistema de parâmetros distribuídos, no qual nós móveis são usados para avaliar as condições locais ao longo do subsistema. Efeitos de transferência de massa são modelados utilizando a aproximação de black-oil. O modelo prediz a localização da frente de acúmulo de líquido no pipeline e do nível de líquido no riser, de maneira que é possível determinar qual tipo de intermitência severa ocorre no sistema. O método das características é usado para simplificar a diferenciação no sistema de equações mistas hiperbólicas-parabólicas resultante. As equações são discretizadas e integradas usando um método implícito com um esquema preditor-corretor para o tratamento das não-linearidades. Simulações correspondentes às condições de intermitência severa são apresentadas e comparadas aos resultados obtidos com o código computacional OLGA, resultando em uma boa concordância. Apresenta-se uma descrição dos tipos de intermitência severa para o escoamento trifásico de gás, óleo e água em um sistema pipeline-riser com efeitos de transferência de massa, assim como um estudo da influência de parâmetros geométricos e de caracterização dos fluidos sobre os mapas de estabilidade. / A mathematical model and numerical simulations are presented to investigate the dynamics of gas, oil and water flow in a pipeline-riser system. The pipeline is modeled as a lumped parameter system and considers two switchable states: one in which the gas is able to penetrate into the riser and another in which there is a liquid accumulation front, preventing the gas from penetrating the riser. The riser model considers a distributed parameter system, in which movable nodes are used to evaluate local conditions along the subsystem. Mass transfer effects are modeled by using a black oil approximation. The model predicts the location of the liquid accumulation front in the pipeline and the liquid level in the riser, so it is possible to determine which type of severe slugging occurs in the system. The method of characteristics is used to simplify the differentiation of the resulting mixed hyperbolic-parabolic system of equations. The equations are discretized and integrated using an implicit method with a predictor-corrector scheme for the treatment of the nonlinearities. Simulations corresponding to severe slugging conditions are presented and compared to results obtained with OLGA computer code, showing a very good agreement. A description of the types of severe slugging for the three-phase flow of gas, oil and water in a pipeline-riser system with mass transfer effects is presented, as well as a study of the influence of geometric and fluid characterization parameters on the stability maps.

I present a systematic method to primary develop existing black oil fields. This method uses integrated reservoir development workflow (IRDW) that relies on integrated asset model (IAM). Developing any existing field means providing a plan that generally serves the development goal(s) specified by management. However, serving the development goal(s) by itself does not guarantee an optimal development plan. Plans that do not rely on an IAM are less accurate. Some plans do not include economics in their evaluation. Such plans are technically accepted but usually impractical or unprofitable. Plans that only evaluate the field based on current, or short-term, conditions are potential candidates for bottlenecks, thus costly reevaluations. In addition, plans that do not consider all suitable options are misleading and have no room for optimization. Finally, some plans are based on “rules of thumb,” ease of operations, or operators’ preference, not on technical evaluation. These plans mostly lower long-term profitability and cause further production problems. To overcome these problems, project management must form a multidisciplinary team that uses the IRDW. The IRDW guides the team through its phases, stages, and steps to selecting the optimal development plan. The IAM consists of geological, reservoir, wellbore, facility, and economic models. The IRDW dictates building an IAM for the base (do nothing) case and for each development plan. The team must evaluate each scenario over the lifetime of the field, or over the timeframe the management specifies. Net present value (NPV) and Present value ratio (PVR) for all options are compared to the base case and against each other. The optimum development plan is the one that have the highest NPV and highest PVR. The results of the research showed that forming a multidisciplinary team and using a LDFC saves time and it guarantees selecting the optimal development plan if all applicable development options are considered.

Reservoir simulation studies are one of the key tools in an integrated reservoir management study. A successful reservoir simulation application requires representative input data for reservoir rock and fluid properties. This study aims to develop a road map from laboratory measurements to the input data file of reservoir simulation and to make a probabilistic approach for the estimation of unknown parameters. Raw data of reservoir rock and fluid properties of a selected oil field of Turkey will be interpreted and prepared in a way that they will be used as input data of a simulator.

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2018. / Submitted by Fabiana Santos (fabianacamargo@bce.unb.br) on 2018-09-19T21:01:16Z No. of bitstreams: 1 2018_AnaCarolinaLoyolaCaetanoRios.pdf: 2923062 bytes, checksum: ebcffecc8676ebe8998b4ec1f3b7416f (MD5) / Approved for entry into archive by Fabiana Santos (fabianacamargo@bce.unb.br) on 2018-09-25T19:38:33Z (GMT) No. of bitstreams: 1 2018_AnaCarolinaLoyolaCaetanoRios.pdf: 2923062 bytes, checksum: ebcffecc8676ebe8998b4ec1f3b7416f (MD5) / Made available in DSpace on 2018-09-25T19:38:33Z (GMT). No. of bitstreams: 1 2018_AnaCarolinaLoyolaCaetanoRios.pdf: 2923062 bytes, checksum: ebcffecc8676ebe8998b4ec1f3b7416f (MD5) Previous issue date: 2018-09-19 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ). / A simulação de reservatórios é uma atividade estratégica da produção de petróleo, feita com o intuito de se estimar a produção, fazer designs e reavaliação de projetos de recuperação, e prever de efeitos mecânicos. A utilidade dos simuladores gera pesquisas em torno da modelagem numérica de reservatórios, de modo a torná-los mais representativos da realidade e mais computacionalmente eficientes. Este trabalho se propõe a revisar os principais métodos e técnicas matemáticas aplicadas na simulação do fluxo multifásico do modelo black oil, alguns dos quais foram implementados em um código para resolução de problemas de fluxo. O fluxo bifásico foi resolvido com a combinação do método dos elementos finitos e do método com volumes de controle centrados no vértice, em um esquema do tipo IMPES. O fluxo não saturado e o modelo black oil foram simulados com o método dos elementos finitos convencional de forma totalmente implícita, sendo que foi proposta a avaliação dos erros utilizando volumes de controle. A estabilidade do método proposto para o tratamento de resíduos na conservação foi analisada. Também foram verificados o efeito do upwind na mobilidade na representação de frentes de saturação e o uso da técnica do tipo pseudogas na descrição do aparecimento de gás pelo modelo black oil. O código implementado foi, então, utilizado na avaliação do comportamento de produção de um reservatório subsaturado, em que foram verificados os efeitos da compressibilidade da rocha e da injeção de água. / Reservoir simulation is strategical in the context of petroleum exploitation, since it provides data for production estimation, design of recuperation projects and prediction of mechanical behavior. For that reason, current researches in the area work on making simulators more computationally efficient and accurate in representing reality. The most popular methods and numerical techniques used in simulation of multiphase and multicomponent flow are reviewed in the present work. A code was developed to simulate unsaturated and two-phase flow and the black oil model. Two-phase flow was solved using the IMPES technique and combined the conventional finite element method with the control volume finite element method. Unsaturated flow and the black oil model were simulated with a fully implicit formulation of the conventional finite element method. The evaluation of errors in mass conservation with the use of control volumes was proposed and the stability of the method of correction of these errors was evaluated. Also, the effects of the upwind in the permeability were observed for the representation of saturation fronts. The efficiency of a technique called pseudogas was evaluated in the representation of gas appearance in the black oil model. Finally, the code was implemented in the analysis of the production behavior of an unsaturated reservoir.

[pt] Nas últimas décadas, grandes investimentos foram feitos no desenvolvimento de modelos e métodos numéricos para prever e analisar os diferentes aspectos do processo de recuperação de óleo e gás. Neste contexto, os simuladores modernos devem ser capazes de incorporar uma grande variedade de opções para responder questões relacionadas ao gerenciamento de reservatórios de forma rápida e precisa. Neste trabalho, nós apresentamos um simulador de reservatórios baseado em uma arquitetura de plugins, onde diferentes formulações, solvers e modelos podem ser desenvolvidos, estendidos e aprimorados. A partir desta abordagem, utilizamos o modelo black-oil para implementar técnicas tradicionais e do estado da arte, como os métodos totalmente e adaptativamente implícito, os métodos de Newton-Raphson e Newton Inexato, controladores heurístico e PID para passo de tempo adaptativo e aproximações de fluxo de um ponto baseados no potencial de fase tradicional e C1-contínuo. Diversas configurações de plugins foram testadas e validadas com simuladores comerciais e seus desempenhos foram utilizados para determinar quais as mais adequadas para resolver problemas de escoamento multifásico. / [en] During the last decades, large investments were made towards the development of numerical models and methods to forecast and analyze the different aspects of oil and gas recovery. In this context, modern simulators must be able to incorporate a wide variety of options to answer questions related to reservoir management accurately and effectively. In this work, we present a reservoir simulator based on a plugin architecture, where different formulations, solvers, and models can be developed, extended, and enhanced. With this approach, we use the black-oil model to implement traditional and state-of-the-art techniques, including fully- and adaptiveimplicit methods, heuristic and PID time-step controllers, Newton-Raphson and Inexact Newton, and C1-continuous and conventional phase-potential single-point upstream weighting. Several plugin configurations were tested and validated with commercial simulators, and their performances were used to determine which are the most suitable to solve multiphase flow problems.

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