The continuous rising of anthropogenic emission into the atmosphere as a consequence of industrial growth is becoming uncontrollable, which causes heating up the atmosphere and changes in global climate. Therefore, CO2 emission becomes a big problem and key issue in environmental concerns. There are several options discussed for reducing the amount of CO2 emitted into the atmosphere. CO2 sequestration is one of these options, which involves the capture of CO2 from hydrocarbon emission sources, e.g. power plants, the injection and storage of CO2 into deep geological formations, e.g. depleted oil reservoirs. The complexity in the structure of geological formations and the processes involved in this method necessitates the use of numerical simulations in revealing the potential problems, determining feasibility, storage capacity, and life span credibility. Field K having 32o API gravity oil in a carbonate formation from southeast Turkey was studied. Field K was put on production in 1982 and produced until 2006, which was very close to its economic lifetime. Thus, it was considered as a candidate for enhanced oil recovery and CO2 sequestration. Reservoir rock and fluid data was first interpreted with available well logging, core and drill stem test data. Monte Carlo simulation was used to evaluate the probable reserve that was 7 million STB, original oil in place (OOIP). The data were then merged into CMG/STARS simulator. History matching study was done with production data to verify the results of the simulator with field data. After obtaining a good match, the different scenarios were realized by using the simulator. From the results of simulation runs, it was realized that CO2 injection can be applied to increase oil recovery, but sequestering of high amount of CO2 was found out to be inappropriate for field K. Therefore, it was decided to focus on oil recovery while CO2 was sequestered within the reservoir. Oil recovery was about 23% of OOIP in 2006 for field K, it reached to 43 % of OOIP by injecting CO2 after defining production and injection scenarios, properly.

A significant percentage of computational time in compositional simulations is spent performing flash calculations to determine the equilibrium compositions of hydrocarbon phases in situ. Flash calculations must be done at each time step for each grid block; thus billions of such calculations are possible. It would be very important to reduce the computational time of flash calculations significantly so that more grid blocks or components may be used. In this dissertation, three different methods are developed that yield fast, robust and accurate phase behavior calculations useful for compositional simulation and other applications. The first approach is to express the mixing rule in equations-of-state (EOS) so that a flash calculation is at most a function of six variables, often referred to as reduced parameters, regardless of the number of pseudocomponents. This is done without sacrificing accuracy and with improved robustness compared with the conventional method. This approach is extended for flash calculations with three or more phases. The reduced method is also derived for use in stability analysis, yielding significant speedup. The second approach improves flash calculations when K-values are assumed constant. We developed a new continuous objective function with improved linearity and specified a small window in which the equilibrium compositions must lie. The calculation speed and robustness of the constant K-value flash are significantly improved. This new approach replaces the Rachford-Rice procedure that is embedded in the conventional flash calculations. In the last approach, a limited compositional model for ternary systems is developed using a novel transformation method. In this method, all tie lines in ternary systems are first transformed to a new compositional space where all tie lines are made parallel. The binodal curves in the transformed space are regressed with any accurate function. Equilibrium phase behavior calculations are then done in this transformed space non-iteratively. The compositions in the transformed space are translated back to the actual compositional space. The new method is very fast and robust because no iteration is required and thus always converges even at the critical point because it is a direct method. The implementation of some of these approaches into compositional simulators, for example UTCOMP or GPAS, shows that they are faster than conventional flash calculations, without sacrificing simulation accuracy. For example, the implementation of the transformation method into UTCOMP shows that the new method is more than ten times faster than conventional flash calculations.

This work is concerned with the application of finite difference simulation to modelling the pressure response in partially penetrating oil wells. This has relevance to the oil and hydrology industries where pressure behaviour is used to infer the nature of aquifer or reservoir properties, particularly permeability. In the case of partially penetrating wells, the pressure response carries information regarding the magnitude of permeability in the vertical direction, a parameter that can be difficult to measure by other means and one that has a direct influence on both the total volumes of oil that can be recovered and on the rate of recovery. The derivation of the non-linear differential equations that form the basis for multiphase fluid flow in porous media is reviewed and it is shown how they can be converted into a set of finite difference equations. Techniques used to solve these equations are explained, with particular emphasis on the approach followed by the commercial simulation package used in this study. This involves use of Newton's method to linearize the equations followed by application of a pre-conditioned successive minimization technique to solve the resulting linear equations. Finite difference simulation is applied to a hypothetical problem of solving pressure response in a partially penetrating well in an homogenous but anisotropic medium and the results compared with those from analytical solutions. Differences between the results are resolved, demonstrating that the required level of accuracy can be achieved through selective use of sufficiently small grid blocks and time-steps. Residual discrepancies with some of the analytical methods can be traced to differences in the boundary conditions used in their derivation. The simulation method is applied to matching a complex real-life well test with vertical and lateral variation in properties (including fluid saturation). An accurate match can be achieved through judicious adjustment of the problem parameters with the proviso that the vertical permeability needs to be high. This suggests that the recovery mechanism in the oil field concerned can be expected to be highly efficient, something that has recently been confirmed by production results. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.

Nowadays there is an ever increasing demand to obtain more accurate numericalsimulation results while at the same time using fewer computations. One area withsuch a demand is oil reservoir simulations, which builds upon Poisson's equation withvariable coefficients (PEWVC). This thesis focuses on applying and testing a high ordernumerical scheme to solve the PEWVC, namely Summation By Parts - SimultaneousApproximation Term (SBP-SAT). The thesis opens with proving that the method isconvergent at arbitrary high orders given sufficiently smooth coefficients. Theconvergence is furthermore verified in practice by test cases on the Poisson'sequation with smoothly variable permeability coefficients. To balance observed lowerboundary flux convergence, the SBP-SAT method was modified with additionalpenalty terms that were subsequently shown to work as expected. Finally theSBP-SAT method was tested on a semi-realistic model of an oil reservoir withdiscontinuous permeability. The correctness of the resulting pressure distributionvaried and it was shown that flux leakage was the probable cause. Hence theproposed SBP-SAT method performs, as expected, very well in continuous settingsbut typically allows undesirable leakage in discontinuous settings. There are possiblefixes, but these are outside the scope of this thesis.

Thesis (Ph. D.). UM #74-17,941. / Title from document title page. Includes bibliographical references. Available in PDF format via the World Wide Web.

Orientador: Denis Jose Schiozer / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica, Instituto de Geociencias / Made available in DSpace on 2018-08-12T22:36:54Z (GMT). No. of bitstreams: 1 Costa_OdairJose_M.pdf: 3077427 bytes, checksum: 9a5e85d5b3ea4c69fdd9a468b62a50de (MD5) Previous issue date: 2008 / Resumo: A reinjeção de água produzida é um método muito utilizado para descarte de água e para suporte de pressão e energia do reservatório. Um problema comum da reinjeção é a perda de injetividade, que prejudica o processo e impede a operação em níveis ótimos de injeção. A perda de injetividade pode ser minimizada pela injeção de água com pressão acima da pressão de fratura do reservatório (IPF), que procura restaurar a capacidade de injeção. Para estudar este processo, um simulador geomecânico para modelagem da fratura é combinado com um simulador numérico de reservatórios para modelar e otimizar a condição de operação dos poços injetores. A fratura é representada por um poço horizontal virtual, de forma conjunta com formulações analíticas de declínio hiperbólico de permeabilidade, para representar o efeito do dano de formação. O objetivo do trabalho é estudar alguns casos para verificar em quais situações a IPF é conveniente. O modelo de simulação estudado foi um reservatório sintético com um arranjo de drenagem de cinco pontos invertido representando uma parte de um reservatório. Foram considerados três cenários, onde a variação foi o tipo de óleo empregado (leve, intermediário e pesado). Estes cenários foram elaborados com a finalidade de representar algumas possíveis situações que podem ocorrer em um campo real, onde a pressão de iniciação de fratura pode ser atingida pelo efeito da perda de injetividade ou devido às propriedades rocha-fluido. O desempenho da IPF foi avaliado utilizando o valor presente líquido (VPL) e produções acumuladas de óleo e água. Os resultados mostraram que o estudo da IPF pode ser considerado como parte de um processo de otimização de vazão de injeção, onde a fratura pode ou não ocorrer. Mostra-se que a IPF, em geral, antecipa a produção de óleo para os casos de viscosidade intermediária e alta, tornando o método bastante vantajoso, embora com maior produção de água. Já estudos com óleo leve indicam que a técnica só é interessante quando houver significativa perda de injetividade, onde a IPF serve como reparadora da injetividade / Abstract: Produced water re-injection is a valuable method of water disposal and pressure and energy support. A common water re-injection problem is the injectivity loss, which affects negatively the process and restrains optimal water injection rates. The injectivity loss can be minimized by water injection with fracture propagation pressure (IFPP), which aims to restore injection capacity. To study this process, a geo-mechanical simulator for fracture modeling combined with a commercial reservoir simulation package is used to model and to optimize the operation condition of water injection wells. The fracture is represented by a virtual horizontal well and analytical formulations of hyperbolic decline of permeability are used to represent the effect of formation damage. This work aims the study of some cases to verify in which situations the IFPP is convenient. The simulation model studied is a synthetic reservoir with a five-spot pattern, representing a region of a reservoir. Three scenarios are considered, with different oil types (light, intermediate and heavy). These scenarios are proposed to reproduce some possible situations, where fracture pressure can be reached by the effect of the injectivity loss or due to rock and fluid characteristics. The behavior of the IFPP is evaluated using the net present value (NPV) and cumulative oil and water productions. The results showed that the IFPP study can be considered as part of an optimization problem of injection flow, where the fracture may occur. It is shown that IFPP, in general, presents advantages for intermediate and high viscosity oil because it anticipates oil production. Studies with light oil indicate that the technique is only interesting when there is significant injectivity loss, where IFPP is desirable for injectivity restoration / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Orientador: Osvair Vidal Trevisan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociencias / Made available in DSpace on 2018-08-15T14:40:24Z (GMT). No. of bitstreams: 1 RibeiroJunior_GuilhermeBlaitterman_M.pdf: 3933004 bytes, checksum: 61894f4b90ecb88d0e0c7b05a71ab1ad (MD5) Previous issue date: 2009 / Resumo: Como as reservas mundiais de óleo leve estão decrescendo continuamente, campos de óleos pesados podem se tornar uma fonte relevante de energia em um futuro próximo. Combustão "In- Situ" (CIS) é uma promissora técnica de recuperação para este tipo de hidrocarboneto, todavia, complexa de se implementar. Tubos de combustão em escala laboratorial e simulações numéricas são essenciais para o dimensionamento de projetos de campo. Este trabalho relata a modelagem numérica de dois experimentos efetuados em escala de laboratório de processos de CIS com um óleo com 12,8º API advindo de um campo candidato para um projeto piloto no Brasil. O estudo numérico foi desenvolvido utilizando o software comercial da CMG, STARS. O objetivo foi analisar o processo, para um modelo físico correspondente ao tubo de combustão utilizado. O modelo de fluido foi ajustado através de um software comercial para um total de sete componentes, óleo pesado, óleo leve, CO2, O2, N2, H2O e coque. Dois processos de combustão foram investigados, o primeiro é o modelo clássico descrito pelo STARS da CMG e o segundo é baseado no modelo de Marín (2007), constituído de frações SARA (saturados, aromáticos, resinas e asfalteno). Os resultados numéricos foram ajustados de acordo com os dados obtidos do experimento. As conclusões sobre este estudo se referem às influências de cada variável sobre o processo global de CIS, em especial a energia de ativação e a entalpia de reação. Além disso, conclui-se que o modelo de fluido e o modelo de reações são fundamentais no ajuste de histórico, assim como a presença de reações sob altas temperaturas são imprescindíveis para se predizer o deslocamento e comportamento da frente de combustão. / Abstract: As the world reserves of light oil steadily decreases, heavy oil and tar sands resources may be an important source of energy. In situ combustion (ISC) is a promising recovery technique for this type of hydrocarbon, otherwise difficult to produce. Combustion tube laboratory experiments and numerical simulations are essential for the design of field projects. This work reports a numeric modeling of two experiments carried out under laboratory scale of in situ combustion process with a 12.8 ºAPI crude from a field candidate to a pilot project in Brazil. The numerical study was developed using the CMG commercial simulator, STARS. The aim was to analyze the process of the physical model corresponding to the combustion tube used. The fluid model was adjusted by a commercial software to a total of 7 components; heavy oil, light oil, CO2, O2, N2, H2O and coke. Two reactions model were analyzed; one is based on the classic combustion model presented by STARS and the other is based on the reactions model proposed by Marín (2007), made up of SARA (saturates, aromatics, resins, and asphaltenes) fractions. The numerical results were history matched to the data derived from the experiment. The important findings in this study were the influences of each variable on the overall ISC process, specifically the activation energy and the enthalpy reaction. It was concluded that the fluid model and the reaction model are key in the history matching task, as well as, the reactions under high temperatures are fundamental to model the combustion front displacement and behavior. / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

Orientador: Denis José Schiozer / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-23T13:02:13Z (GMT). No. of bitstreams: 1 MunozMazo_EduinOrlando_D.pdf: 5130890 bytes, checksum: d577582a347f8585e79c27a461f4bf93 (MD5) Previous issue date: 2013 / Resumo: A injeção de água como método para auxiliar na recuperação de hidrocarbonetos e na manutenção da pressão em reservatórios tem sido aplicada de maneira crescente nas últimas décadas devido às suas características de eficiência, baixo custo e alta disponibilidade da água, o que faz com que este procedimento seja considerado com frequência na fase de desenvolvimento de campos de petróleo, como parte da estratégia inicial de produção. No entanto, volumes cada vez maiores de água produzida são reportados pelas companhias operadoras, com grandes implicações técnicas e econômicas para as mesmas. Esta situação pode, em alguns casos, fazer com que a água deixe de ser considerada como um recurso e passe a ser vista como um empecilho à produção. Outro problema associado à injeção de água em reservatórios é a perda de injetividade causada pela diminuição da permeabilidade na região vizinha aos poços injetores, decorrente do dano de formação. Portanto, implementar soluções ao problema da perda de injetividade e considerar o controle da água injetada e produzida na etapa de lançamento e otimização de estratégias de produção têm um impacto significativo no desempenho produtivo e financeiro de um projeto de exploração e produção (E&P), especialmente em reservatórios heterogêneos e fraturados, onde as propriedades petrofísicas trazem consequências importantes no escoamento dos fluidos de injeção e produção. Nesse trabalho é realizada uma análise da aplicação do processo de injeção com pressão de propagação de fratura (Injection with Fracture Propagation Pressure - IFPP) mediante a modelagem dos processos de perda de injetividade e propagação de fratura utilizando ferramentas de simulação de uso comercial. Posteriormente, uma metodologia para o gerenciamento de água baseada no controle dos volumes de injeção e produção de água é proposta e aplicada para casos de reservatório heterogêneo e naturalmente fraturado. Os resultados apontam que a injeção de água com propagação de fratura pode ser utilizada para remediar os efeitos nocivos da perda de injetividade, permitindo, em alguns casos, um aumento significativo da recuperação de óleo. Apontam também que a sua modelagem pode ser estudada como um problema de otimização de vazão, evidenciando a necessidade de inclusão do controle da injeção (otimização de vazão e determinação da data de fechamento do poço injetor) na fase de proposta e posterior otimização de estratégias de produção. Finalmente, mostram o efeito positivo do controle da injeção de água, aliado ao controle da produção, como mecanismo para o gerenciamento de água, possibilitando um melhor desempenho produtivo e financeiro de reservatórios heterogêneos e fraturados que utilizam a injeção de água como método de recuperação secundária / Abstract: Water injection as a method to assist hydrocarbon recovery and reservoir pressure maintenance has been applied increasingly in recent decades because of its characteristics of efficiency, low cost and high availability of water. This makes this procedure often considered in the development of oil fields as part of the initial production strategy. However, increasing volumes of produced water have been reported by the operating companies, with major technical and economic implications for them. This may cause the water to stop being regarded as a resource and to start to be seen as a constraint to the production. Another problem associated with water injection into the reservoir is the injectivity loss caused by the permeability decrease in the region adjacent to the injection wells due to the formation damage. Therefore, implementing solutions to the problem of injectivity loss and considering the control of injected and produced water in the proposal and optimization of production strategy stage have a significant impact on the productive and financial performance of exploration and production (E&P) projects. This happens in heterogeneous and fractured reservoirs, where the petrophysical properties have a significant impact on the flow of injection and production fluids. In this work is carried out an analysis of the application of the injection with fracture propagation pressure (IFPP) process by modeling injectivity loss and fracture propagation using commercial simulation tools. Subsequently, a methodology for water management based on control of injection volumes and water production is proposed and applied to cases of heterogeneous and naturally fractured reservoirs. The results show that water injection with fracture propagation can be used to remedy the harmful effects of injectivity loss allowing, in some cases, a significant increase in oil recovery. Also indicate that its modeling can be studied as a flow rate optimization problem, highlighting the need for the inclusion of the injection control (optimization of the injection rate and shutting time of the injection well) at the proposal and subsequent optimization stage of production strategies. Finally, show the positive effect of the control of water injection, coupled to the control of water production, as a mechanism for managing water, providing better productive and financial performance for heterogeneous and fractured reservoirs using water injection as a method of improved oil recovery / Doutorado / Reservatórios e Gestão / Doutor em Ciências e Engenharia de Petróleo

The Aneth Field in the Paradox Basin (SE Utah) has produced nearly 500 MMbbls of oil from phylloid-algal and oolitic carbonate reservoirs of the lower and upper Desert Creek (Paradox Formation, Middle Pennsylvanian) sequences, respectively. The oil resides in a 150 to 200 foot-thick isolated carbonate platform located in a distal ramp setting on the southwest margin of the Paradox Basin. The horseshoe-shaped platform is roughly 12 miles in diameter with an aerial extent of approximately 144 square miles. Evaluation of the platform-to-basin transition on the leeward (southern) margin of the Aneth Platform, the focus of this study, was made possible through Resolute Energy's 2017 donation of well data and core to the Utah Geological Survey Core Research Center. The lower Desert Creek sequence ranges from 50 to 100 feet in thickness and produces from a succession of phylloid-algal, boundstone-capped parasequences in the Aneth Platform. The upper Desert Creek sequence is generally thinner across the platform and is characterized by a succession of oolite-capped parasequences, except on the southern margin of the platform where it ranges from 80 to 115 feet in thickness. The upper Desert Creek thick resulted from southward shedding of platform-derived carbonate sediment and lesser amounts of quartz silt and very fine sand off the low-angle southern platform margin slope. A nine-mile-long, north-south-oriented stratigraphic panel constructed from log and core data permits characterization of thickness and facies trends through the upper Desert Creek from platform (north) to slope to distal basin (south) in the Ratherford unit. In the southern margin, five novel facies for the Aneth Field were analyzed, described, and interpreted using a sequence stratigraphic framework, all of which represent deposition on a gravity-influenced platform-edge slope. It is interpreted that the slope facies association was deposited during transgression and highstand and was generally a result of oversteepened slopes as a function of the carbonate factory on the platform being highly productive. Slope and basin facies range from proximal rudstone and floatstone to thin, graded distal turbidites, the latter of which extend at least five miles into the basin. Compaction of the muddy and fine-grained allochthonous sediment followed by pervasive calcite and anhydrite cementation has destroyed any primary porosity in the platform-derived slope-to-basin sediments.

Made available in DSpace on 2014-12-17T14:08:55Z (GMT). No. of bitstreams: 1 TayllandyaSP_DISSERT.pdf: 2803522 bytes, checksum: 516959be83003bd573c721b4ad05b984 (MD5) Previous issue date: 2013-11-06 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Nowadays, most of the hydrocarbon reserves in the world are in the form of heavy oil, ultra - heavy or bitumen. For the extraction and production of this resource is required to implement new technologies. One of the promising processes for the recovery of this oil is the Expanding Solvent Steam Assisted Gravity Drainage (ES-SAGD) which uses two parallel horizontal wells, where the injection well is situated vertically above the production well. The completion of the process occurs upon injection of a hydrocarbon additive at low concentration in conjunction with steam. The steam adds heat to reduce the viscosity of the oil and solvent aids in reducing the interfacial tension between oil/ solvent. The main force acting in this process is the gravitational and the heat transfer takes place by conduction, convection and latent heat of steam. In this study was used the discretized wellbore model, where the well is discretized in the same way that the reservoir and each section of the well treated as a block of grid, with interblock connection with the reservoir. This study aims to analyze the influence of the pressure drop and heat along the injection well in the ES-SAGD process. The model used for the study is a homogeneous reservoir, semi synthetic with characteristics of the Brazilian Northeast and numerical simulations were performed using the STARS thermal simulator from CMG (Computer Modelling Group). The operational parameters analyzed were: percentage of solvent injected, the flow of steam injection, vertical distance between the wells and steam quality. All of them were significant in oil recovery factor positively influencing this. The results showed that, for all cases analyzed, the model considers the pressure drop has cumulative production of oil below its respective model that disregards such loss. This difference is more pronounced the lower the value of the flow of steam injection / Atualmente, a maior parte das reservas de hidrocarbonetos no mundo se encontram na forma de ?leo pesado, ultra-pesado ou betume. Para a extra??o e produ??o desse recurso ? necess?ria a implanta??o de novas tecnologias. Um dos processos promissores para a recupera??o desse ?leo ? a drenagem gravitacional assistida com vapor e solvente (ESSAGD) que utiliza dois po?os horizontais paralelos, onde o injetor ? disposto acima do produtor. A realiza??o do processo se d? mediante a inje??o de um aditivo de hidrocarboneto em baixa concentra??o em conjunto com vapor. O vapor contribui com calor para redu??o da viscosidade do ?leo e o solvente ajuda na miscibilidade, reduzindo a tens?o interfacial entre ?leo/solvente. A principal for?a atuante neste processo ? a gravitacional e a transfer?ncia de calor ocorre por meio da condu??o, convec??o e pelo calor latente do vapor. Neste estudo foi utilizado o modelo discretizado, onde o po?o ? discretizado da mesma forma que o reservat?rio, sendo cada se??o do po?o tratada como um bloco da grade, com conex?o interblocos com o reservat?rio. O presente trabalho tem como objetivo analisar a influ?ncia da perda de carga e calor ao longo do po?o injetor no processo ES-SAGD. O modelo utilizado para estudo trata-se de um reservat?rio homog?neo, semissint?tico com caracter?sticas do Nordeste Brasileiro e as simula??es num?ricas foram realizadas atrav?s do simulador t?rmico STARS da CMG (Computer Modelling Group). Os par?metros operacionais analisados foram: porcentagem de solvente injetado, vaz?o de inje??o de vapor, dist?ncia vertical entre os po?os e qualidade de vapor. Todos eles foram significativos no Fator de Recupera??o de ?leo. Os resultados demonstraram que, para todos os casos analisados, o modelo que considera a perda de carga apresenta produ??o acumulada de ?leo inferior ao seu respectivo modelo que desconsidera tal perda. Essa diferen?a ? mais acentuada quanto menor o valor da vaz?o de inje??o de vapor