11 |
Contribution to the understanding of filtration and pressure drop phenomena in wall-flow DPFsAngiolini, Emanuele 01 September 2017 (has links)
From the last decades of the 20th century, internal combustion engines
have undergone a continuous improvement process aimed to the increase
of their efficiency and decrease of the pollutants emissions. The reduction
of the availability of fossil fuel and the increase of human-made pollution
observed in the last decades is leading worldwide to more stringent
emission standards that make the engine manufacturers to constantly
look for fuel consumption and emission reductions while keeping engine
performance.
To comply with current and incoming emission regulations, the exhaust
line of internal combustion engines has been gradually complicated by the
presence of aftertreatment systems. Among them, the particulate filter
is the device in charge of abating the emission of soot in the atmosphere.
Concerning compression ignition engines, diesel particulate filters (DPF)
were first commercially utilized in significant numbers in passenger car
and heavy-duty engines since the beginning of the 21st century. Euro
6 emission standards limits the emitted particulate matter from direct
injection engines, thus extending the use of particulate filters also to direct
injection gasoline engines.
A deep knowledge of the phenomena happening inside the DPF is
required for the correct understanding of the behaviour of this system and
its interaction with the engine. The precise knowledge of the filtration and
pressure drop processes is mandatory for the design of the particulate filter
and is also essential to wisely think up and analyse solutions aimed to
limit the negative impact of the filter on the fuel consumption maintaining
its capability of retaining soot particles.
Thus, the present work pretends to provide a contribution to the understanding
of these phenomena in wall-flow DPFs. The problem has been
faced on a computational and experimental basis. A notable part of the
work was dedicated to the development and validation of a one-dimensional
DPF filtration model to be coupled with the existing pressure drop model.
The model was implemented in OpenWAM¿, the open-source gas dynamics
software for internal combustion engines and components computation
developed at CMT - Motores Térmicos.
The developed computational tool was applied to the assessment of
the aftertreatment (DOC&DPF) volume downsizing potential in post- and
pre-turbo aftertreatment configuration. The study is completed with experimental
analysis to support theoretical insights discussing how the soot
deposition profile and the particulate layer properties impact on the DPF
pressure drop. / Desde las últimas décadas del siglo XX, se ha producido un proceso de
mejora continua de los motores de combustión interna alternativos con el
fin de aumentar su eficiencia y reducir las emisiones contaminantes. La
reducción de la disponibilidad de combustibles fósiles y el incremento de
la polución de origen antropogénico observados en las ultimas décadas ha
provocado el progresivo endurecimiento de las normativas anticontaminación
a nivel mundial obligando a los fabricantes de motores a buscar la
reducción continua del consumo de combustible y emisiones, manteniendo
las prestaciones del motor.
El cumplimiento de las actuales y futuras normativas anticontaminación
requiere de la instalación de diversos sistemas de postratamiento
de gases en la línea de escape de los motores de combustión interna alternativos,
aumentando su complejidad. Entre estos sistemas, el filtro de
partículas es el equipo encargado de la reducción de la emisión de hollín
a la atmósfera. Con respeto a los motores de encendido por compresión,
los filtros de partículas diésel se implementaron por primera vez de forma
masiva en vehículos de pasajeros y vehículos pesados a principio del siglo
XXI. La normativa anti contaminación Euro 6 limita las emisiones de
partículas de los motores de inyección directa, extendiendo el uso de filtros
de partículas a los motores de inyección directa de gasolina.
Es necesario tener un conocimiento profundo de los fenómenos que
tienen lugar en el DPF para comprender el comportamiento de este sistema
y su interacción con el motor. El conocimiento de los procesos de filtrado y
perdida de presión es vital para el diseño del filtro de partículas y resulta
esencial para encontrar y analizar soluciones que ayuden a limitar el
impacto negativo del DPF sobre el consumo de combustible sin perder la
capacidad de retener partículas de hollín.
En este contexto, este trabajo pretende aportar una contribucción a
la comprensión de estos fenómenos en filtros de partículas de flujo de
pared. Esta tarea se ha planteado desde un punto de vista computacional
y experimental. Parte importante de este trabajo ha consistido en el
desarrollo y validación de un modelo de filtrado unidimensional de DPF
que se ha acoplado con el modelo de caida de presión ya existente. El
modelo se ha implementado en OpenWAM¿, el software de libre acceso
para el cálculo fluidodinámico de motores de combustión interna y sus
componentes desarrollado en CMT - Motores Térmicos.
La herramienta computacional desarrollada se ha aplicado a la evaluación
del potencial de reducción de volumen de sistemas de postratamiento
(DOC&DPF) en configuraciones post- y pre-turbo. Este estudio se ha completado
con un análisis experimental para dar respaldo a los conceptos
teóricos empleados discutiendo como el perfil de deposición del hollín y las
propiedades de la capa de partículas afectan a la perdida de presión del
DPF. / Des les últimes dècades del segle XX, s'ha produït un procés de millora
contínua dels motors de combustió interna alternatius amb l'objectiu
d'augmentar la seua eficiència i reduir les emissions contaminants. La
reducció de la disponibilitat de combustibles fòssils i l'increment de la
polució d'origen antropòlogic observats en les últimes dècades ha provocat
que les normatives anticontaminació s'han fet més rígides a nivell mundial,
obligant als fabricants de motors a buscar la reducció contínua del consum
de combustibles i emissions, mantenint les prestacions dels motors.
El cumpliment de les normes anticontaminació actuals i futures, requereixen
de l'instalació de diversos sistemes de post-tractament de gasos
a l'eixida dels motors de combustió interna alternatius, llavors augmentant
la complexitat. Entre aquestos sistemes, el filtre de partícules es
l'equip encarregat de la reducció de les partícules de sutge a l'atmosfera.
Respecte als motors d'encès per compressió, els filtres de partícules van
instalar-se de manera massiva als vehicles de passatgers i vehicles pesats
al principi del segle XXI. La normativa anti contaminació Euro 6 limita
les emissions de partícules dels motors d'inyecció directa, estenent l'ús del
filtre de partícules als motors d'injecció directa de gasolina.
És necessari tindre un coneixement dels fenòmens que tenen lloc al
DPF per a comprendre el comportament del sistema i la seua interacció
amb el motor. El coneixement dels processos de filtrat i la pèrdua de
pressió és vital per al diseny del filtre de partícules i resulta essencial per
a trobar i analitzar les solucions que ajuden a limitar l'impacte negatiu del
DPF sobre el consum de combustible sense perdre la capacitat de retenir
partícules de sutge.
En aquest context, el projecte pretén aportar una contribució a la comprensió
d'aquestos fenòmens en els filtres de partícules de flux de paret.
Aquesta feina s'ha plantejat des d'un punt de vista computacional i experimental.
Part important d'aquest treball ha consistit en el desenvolupament
i validació d'un model de filtrat unidimensional de DPF que s'ha acoplat
a un model de pèrdua de pressió existent. El model s'ha implementat en
OpenWAM¿, el software de lliure accés per al cálcul fluidodinámic de
motors de combustió interna i els seus components desenvolupats al CMT -
Motores Térmicos.
La ferramenta computacional desenvolupada s'ha aplicat a la evaluació
del potencial de reducció del volum de sistemes de post tractament
(DOC&DPF) en les configuracions post- i pre-turbo. Aquest estudi s'ha completat
amb una anàlisi experimental per a donar suport als concepts teòrics
emprats discutint com el perfil de la disposició de sutge i les propietats de
la capa de partícules que afecten a la pèrdua de pressió del DPF. / Angiolini, E. (2017). Contribution to the understanding of filtration and pressure drop phenomena in wall-flow DPFs [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86157
|
12 |
A carbonate reservoir model for Petersilie field in Ness County, Kansas: effective waterflooding in the Mississippian SystemMcCaw, Alyson Siobhan January 1900 (has links)
Master of Science / Department of Geology / Matthew Totten / The Petersilie oil field in Ness County, Kansas produces out of the Mississippian System, a reservoir composed mainly of shallow water carbonates, at depths of around 4375 ft (1334 m). The lithology of the field ranges from limestone to dolomite, to interlaminated limestone-dolomite beds. Chert is commonly found throughout. Petersilie field lies to the west of the Central Kansas Uplift, and to the east of the Hugoton Embayment. The field saw much drilling activity in the 1960’s, when it reached a production peak of nearly 378,000 barrels of oil per year. Production declined swiftly after that until the late 1990’s, when waterflooding was successfully employed.
In this study, a reservoir model was produced for the Mississippian as it occurs in Petersilie field using the Department of Energy’s EdBOAST reservoir modeling software, with the intent of providing a reference for future drilling activity in the Mississippian and determining reservoir characteristics that may have contributed to the effectiveness of waterflooding in this area. The reservoir model was checked by simulation with a companion reservoir simulator program, BOAST 98. Subsequent comparison of simulated and actual oil production curves demonstrates the reliability of well log and drill stem test data for the field and proves the reservoir model to be a good fit for the Mississippian in Petersilie.
Production curve analysis of Petersilie indicates the field was an ideal candidate for waterflooding because it has a solution-gas drive mechanism. As the field approached depletion from primary recovery, oil saturations remained high. Petersilie also exhibits high porosity and good permeability. The BOAST software was found to be an effective and inexpensive means for understanding the Mississippian reservoir in central to south-central Kansas. It was determined that BOAST has potential for practical use by smaller independent oil companies targeting the Mississippian in Kansas.
|
13 |
DIRECT OBSERVATION OF CHARACTERISTIC DISSOCIATION BEHABIORS OF HYDRATE-BEARING CORES BY RAPID-SCANNING X-RAY CT IMAGINGEbinuma, Takao, Oyama, Hiroyuki, Utiumi, Takashi, Nagao, Jiro, Narita, Hideo 07 1900 (has links)
Experiments involving the dissociation of artificial methane-hydrate-bearing sediments were performed using X-ray computed tomography (X-CT, 40 s scanning speed at 2 min intervals) to directly observe dissociation behavior in the sediments and the gas and water flows generated by dissociation. Dissociation by depressurization was performed using a backpressure regulator, and showed that the temperature reduction induced by depressurization depends on the phase equilibrium state of methane hydrate, and that preferential dissociation occurs along the periphery of the core. This behavior is caused by heat flux from the outside of the core, and this controls the dissociation rate. A heat exchanger was installed at one end of the core to simulate thermal stimulation, and propagation of a clear and unidirectional dissociation front was observed. Depending on the heating temperature, the dissociation rate was less than that observed for depressurization. Hot water was also injected at a constant rate from the bottom of the core, and CT images showed the movement of distinct accumulations of dissociated gas being pushed by the hot water. The gas production rate increased immediately after the gas accumulation reached the opposite end of the core where the gas and water flow out.
|
14 |
NUMERICAL STUDY ON PERMEABILITY HYSTERESIS DURING HYDRATE DISSOCIATION IN HOT WATER INJECTIONKonno, Yoshihiro, Masuda, Yoshihiro, Takenaka, Tsuguhito, Oyama, Hiroyuki, Ouchi, Hisanao, Kurihara, Masanori 07 1900 (has links)
Hot water injection is a production technique proposed to gas recovery from methane hydrate
reservoirs. However, from a practical point of view, the injected water experiences a drop in
temperature and re-formation of hydrates may occur in the reservoir. In this work, we proposed a
model expressing permeability hysteresis in the processes between hydrate growth and
dissociation, and studied hydrate dissociation behavior during hot water injection. The model of
permeability hysteresis was incorporated into the simulator MH21-HYDRES (MH21 Hydrate
Reservoir Simulator), where the decrease in permeability with hydrate saturation during hydrate
growth process was assumed to be much larger than the decrease during hydrate dissociation
process. Laboratory hydrate dissociation experiments were carried out for comparison. In each
experiment, we injected hot water at a constant rate into a sand-packed core bearing hydrates, and
the histories of injection pressure, core temperature, and gas/water production rates were
measured. Numerical simulations for the core experiments showed the re-formation of hydrates
led to the increase in injection pressure during hot water injection. The simulated tendencies of
pressure increase varied markedly by considering permeability hysteresis. Since the experimental
pressure increases could not be reproduced without the permeability hysteresis model, the
influence of permeability hysteresis should be considered to apply hot water injection to hydrate
reservoirs.
|
15 |
[en] VISUALIZATION IN MICROMODELS OF OIL DISPLACEMENT BY O/W EMULSIONS / [pt] VISUALIZAÇÃO EM MICROMODELOS DA RECUPERAÇÃO DE ÓLEO POR EMULSÕES O/WGABRIEL BARROCAS DE OLIVEIRA CRUZ 14 January 2019 (has links)
[pt] A eficiência do processo de injeção de água, o método de recuperação secundária mais comum na indústria do petróleo, é limitada por seu padrão de varredura não uniforme, originado da formação de caminhos preferenciais devido à alta razão de mobilidade entre água e óleo, e a elevada saturação de óleo residual, associada aos efeitos capilares. A fim de melhorar a recuperação de petróleo, diferentes abordagens têm sido sugeridas na literatura, com algumas delas baseadas no bloqueio de poros e consequente desvio de água, varrendo assim uma área maior do reservatório e deslocando mais do óleo aprisionado por capilaridade. O bloqueio de poros pode ser realizado com diferentes métodos, sendo um deles a injeção de emulsão, com a fase dispersa, composta por gotas de óleo, atuando como o agente responsável pela
diminuição da mobilidade da fase aquosa. Neste trabalho, os mecanismos fundamentais do processo de injeção de emulsão foram estudados experimentalmente, visualizando-se o escoamento em escala de poros em um dispositivo micro-fluídico de vidro composto por uma rede de canais constritos, que modela as principais características de um meio poroso. Os resultados mostram o efeito do tamanho da gota e do número de capilaridade no padrão do escoamento, no tamanho dos gânglios do óleo aprisionado e na recuperação de óleo residual. / [en] The efficiency of water flooding, the most common secondary recovery method in the oil industry, is limited by its non-uniform sweep pattern, originating from the formation of preferential paths because of the high mobility ratio between water and oil, and the high residual oil saturation, associated with capillary oil trapping. In order to improve oil recovery, different approaches have been suggested in the literature, with some of them based on pore blocking and consequent water diversion, thus sweeping a bigger area of the reservoir and displacing more of the trapped oil. Pore blockage can be performed with different methods, one of which is emulsion flooding, with the disperse phase, composed by oil drops, acting as the agent responsible for the decreased water phase mobility. In this work, the fundamental mechanisms of emulsion
flooding process was studied experimentally, by visualizing the pore-scale flow in a glass microfluidic device composed of a network of constricted channels, that models the main features of a porous media. The results show the effect of drop size and capillary number on the flow pattern, trapped oil ganglia size and residual oil recovery.
|
16 |
Modelagem de injeção de agua acima da pressão de fratura do reservatorio atraves de poço horizontal virtual / Modeling water injection above reservoir formation parting pressure through a virtual horizontal wellMontoya Moreno, Juan Manuel 02 January 2007 (has links)
Orientador: Denis Jose Schiozer / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias / Made available in DSpace on 2018-08-12T08:32:24Z (GMT). No. of bitstreams: 1
MontoyaMoreno_JuanManuel_M.pdf: 2098742 bytes, checksum: c03cbaf7c1d95c189a074da09d33d7dd (MD5)
Previous issue date: 2007 / Resumo: A injeção de água tem sido um método de recuperação de petróleo muito usado na industria do petróleo. Um dos principais problemas associados a este método e a perda da injetividade. Diferentes procedimentos tem sido propostos para minimizar os efeitos de tal perda, um dos quais e a injeção acima da pressão de fratura, que consiste em injetar água com pressão suficiente para criar canais de alta condutividade, com o objetivo de restaurar a injetividade inicial do poço. Este procedimento tem se mostrado viável, tendo como vantagem à manutenção da injetividade em valores similares aos iniciais, embora apresente dificuldade de modelagem e incertezas em relação à eficiência de varrido, ao comportamento da frente de avanço da fratura e a influencia desta na recirculação da água. Uma forma adequada de modelar esse fenômeno e a integração da geomecanica com a simulação de escoamento, mas este tipo de abordagem envolve maior custo computacional, alem de não ter sido completamente implementado em aplicações comerciais, o que dificulta aplicações praticas. Outras diferentes técnicas de simulação são usadas para modelar o fenômeno, tais como modificadores de transmissibilidade associados a refinamentos locais de malha. Neste trabalho, e proposta a simulação da fratura por meio do uso de um poço horizontal virtual, usando um simulador comercial de escoamento e um software para simulações de processos de faturamento hidráulico acoplados explicitamente. De inicio, modela-se a perda de injetividade num poço injetor de água e, junto com o modelo geomecanica de fratura, usam-se modificadores de transmissibilidade para modelar a fratura como modelo de referencia. Posteriormente, introduz-se um modelo de fratura representado por um poço horizontal virtual mediante programação em simuladores comerciais. Os resultados mostram que o poço horizontal virtual representa adequadamente o comportamento da fratura em relação ao modelo de modificadores de transmissibilidade, evitando necessidade de refinamentos locais, tornando-se uma ferramenta útil para simular casos de campo em grande escala. Palavras-Chave: simulação de reservatório; injeção de água; perda de injetividade; injeção de água acima da pressão de fratura; geomecanica. / Abstract: Water injection has been the most used method to improve oil recovery. The main problem of this method, related directly with operational efficiency, is the injectivity loss which is the loss of capacity to maintain water injection rates due to formation damage. Different models have been proposed to minimize the injectivity loss effects due to its high economic impact on oil production. One of these methods is water injection above formation parting pressure. It consists in creating high conductivity channels inside the reservoir to restore or to increase well injectivity. This method has advantages associated with injectivity maintenance but it is difficult to model and it presents uncertainties in relation to sweep efficiency, to fracture tip behavior and its influence on the water re-circulation. One way to model the problem is the integration of geomechanical and flow simulation, but it requires a higher computation time and it has not been completely implemented in commercial simulators. Different techniques are used to model the water injection above formation parting pressure, such as transmissibility modifiers associated with local grid refinement. In this work, a methodology is proposed for fracture simulation using both numerical fluid flow and geomechanical simulators, coupled explicitly, using a virtual well to model the fracture. Initially, injectivity loss is modeled and, along with geomechanical fracture model, transmissibility modifiers are used to model the fracture. This model represents the reference fracture model. Then, the fracture is represented by a virtual horizontal well, allowing easy implementation into commercial simulators. The results show that the virtual horizontal well represents adequately the fracture's behavior given by the reference model, avoiding local grid refinement and, allowing full field scale simulations without simulation grid modification. / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo
|
17 |
Modeling the effect of injecting low salinity water on oil recovery from carbonate reservoirsAl Shalabi, Emad Waleed 10 February 2015 (has links)
The low salinity water injection technique (LSWI) has become one of the important research topics in the oil industry because of its possible advantages for improving oil recovery. Several mechanisms describing the LSWI process have been suggested in the literature; however, there is no consensus on a single main mechanism for the low salinity effect on oil recovery. As a result of the latter, there are few models for LSWI and especially for carbonates due to their heterogeneity and complexity. In this research, we proposed a systematic approach for modeling the LSWI effect on oil recovery from carbonates by proposing six different methods for history matching and three different LSWI models for the UTCHEM simulator, empirical, fundamental, and mechanistic LSWI models. The empirical LSWI model uses contact angle measurements and injected water salinity. The fundamental LSWI model captures the effect of LSWI through the trapping number. In the mechanistic LSWI model, we include the effect of different geochemical reactions through Gibbs free energy. Moreover, field-scale predictions of LSWI were performed and followed by a sensitivity analysis for the most influential design parameters using design of experiment (DoE). The LSWI technique was also optimized using the response surface methodology (RSM) where a response surface was built. Also, we moved a step further by investigating the combined effect of injecting low salinity water and carbon dioxide on oil recovery from carbonates through modeling of the process and numerical simulations using the UTCOMP simulator. The analysis showed that CO₂ is the main controller of the residual oil saturation whereas the low salinity water boosts the oil production rate by increasing the oil relative permeability through wettability alteration towards a more water-wet state. In addition, geochemical modeling of LSWI only and the combined effect of LSWI and CO₂ were performed using both UTCHEM and PHREEQC upon which the geochemical model in UTCHEM was modified and validated against PHREEQC. Based on the geochemical interpretation of the LSWI technique, we believe that wettability alteration is the main contributor to the LSWI effect on oil recovery from carbonates by anhydrite dissolution and surface charge change through pH exceeding the point of zero charge. / text
|
18 |
Otimiza??o de vaz?o de po?os injetores em projeto de inje??o de ?gua utilizando simula??o por linhas de fluxoParente, Jos? Tupinamb? Mont' Alverne 15 December 2008 (has links)
Made available in DSpace on 2014-12-17T14:08:32Z (GMT). No. of bitstreams: 1
JoseTMAP.pdf: 3429155 bytes, checksum: 9d06d453f156a78546476b9e1a22c995 (MD5)
Previous issue date: 2008-12-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Until the early 90s, the simulation of fluid flow in oil reservoir basically used the numerical technique of finite differences. Since then, there was a big development in simulation
technology based on streamlines, so that nowadays it is being used in several cases and it can represent the physical mechanisms that influence the fluid flow, such as compressibility, capillarity and gravitational segregation. Streamline-based flow simulation is a tool that can
help enough in waterflood project management, because it provides important information not available through traditional simulation of finite differences and shows, in a direct way, the influence between injector well and producer well. This work presents the application of a methodology published in literature for optimizing water injection projects in modeling of a Brazilian Potiguar Basin reservoir that has a large number of wells. This methodology considers changes of injection well rates over time, based on information available through streamline simulation. This methodology reduces injection rates in wells of lower efficiency and increases injection rates in more efficient wells. In the proposed model, the methodology was effective. The optimized alternatives presented higher oil recovery associated with a lower water injection volume. This shows better efficiency and, consequently, reduction in costs. Considering the wide use of the water injection in oil fields, the positive outcome of the
modeling is important, because it shows a case study of increasing of oil recovery achieved simply through better distribution of water injection rates / At? o in?cio da d?cada de 90, a simula??o de fluxo em reservat?rio de petr?leo basicamente utilizava a t?cnica num?rica de diferen?as finitas. Desde ent?o, houve um grande
desenvolvimento da tecnologia de simula??o com base em linhas de fluxo, de modo que hoje ela tem sido usada em v?rios casos e se encontra adequada para representar os diversos mecanismos f?sicos que influenciam o fluxo de fluidos no reservat?rio, tais como compressibilidade, capilaridade e segrega??o gravitacional. A simula??o baseada em linhas de
fluxo ? uma ferramenta que pode ajudar bastante no gerenciamento de projetos de inje??o de ?gua, pois fornece informa??es importantes n?o disponibilizadas atrav?s da simula??o tradicional de diferen?as finitas e mostra, de forma direta, a influ?ncia entre po?o injetor e po?o produtor. Este trabalho apresenta a aplica??o de uma metodologia existente na literatura para otimizar projeto de inje??o de ?gua em um reservat?rio pertencente a um campo de petr?leo da Bacia Potiguar que possui elevado n?mero de po?os. Esta metodologia considera modifica??es das cotas de inje??o dos po?os ao longo do tempo, com base nas informa??es
dispon?veis atrav?s da simula??o por linhas de fluxo. Esta metodologia reduz as vaz?es de inje??o dos po?os de menor efici?ncia e aumenta as vaz?es de inje??o dos po?os mais
eficientes. No modelo proposto, a metodologia se mostrou eficaz. As alternativas de otimiza??o apresentaram uma maior recupera??o de ?leo associada a um menor volume de
inje??o de ?gua. Isto demonstra uma melhor efici?ncia e, consequentemente, uma redu??o de custos. Considerando a ampla utiliza??o da inje??o de ?gua em campos de petr?leo, o
resultado positivo da modelagem ? importante, porque apresenta um estudo de caso de aumento da recupera??o de petr?leo, alcan?ado simplesmente atrav?s de uma melhor
distribui??o das vaz?es de inje??o de ?gua
|
19 |
An?lise comparativa entre simuladores de linha de fluxo e diferen?as finitas para um reservat?rio de petr?leo submetido a inje??o de ?guaAlencar Filho, Martinho Quintas de 27 May 2011 (has links)
Made available in DSpace on 2014-12-17T14:08:47Z (GMT). No. of bitstreams: 1
MartinhoQAF_DISSERT.pdf: 3517855 bytes, checksum: e2d79876500fdde55b949a6a832b6ff0 (MD5)
Previous issue date: 2011-05-27 / Water injection is the most widely used method for supplementary recovery in many oil
fields due to various reasons, like the fact that water is an effective displacing agent of low
viscosity oils, the water injection projects are relatively simple to establish and the water
availability at a relatively low cost. For design of water injection projects is necessary to do
reservoir studies in order to define the various parameters needed to increase the effectiveness
of the method. For this kind of study can be used several mathematical models classified into
two general categories: analytical or numerical.
The present work aims to do a comparative analysis between the results presented by
flow lines simulator and conventional finite differences simulator; both types of simulators are
based on numerical methods designed to model light oil reservoirs subjected to water
injection. Therefore, it was defined two reservoir models: the first one was a heterogeneous
model whose petrophysical properties vary along the reservoir and the other one was created
using average petrophysical properties obtained from the first model. Comparisons were done
considering that the results of these two models were always in the same operational
conditions. Then some rock and fluid parameters have been changed in both models and
again the results were compared. From the factorial design, that was done to study the
sensitivity analysis of reservoir parameters, a few cases were chosen to study the role of water
injection rate and the vertical position of wells perforations in production forecast. It was
observed that the results from the two simulators are quite similar in most of the cases;
differences were found only in those cases where there was an increase in gas solubility ratio
of the model. Thus, it was concluded that in flow simulation of reservoirs analogous of those
now studied, mainly when the gas solubility ratio is low, the conventional finite differences
simulator may be replaced by flow lines simulator the production forecast is compatible but
the computational processing time is lower. / A inje??o de ?gua ? o m?todo de recupera??o suplementar mais difundido na maioria
dos campos de petr?leo, devido a v?rios motivos, como o fato de a ?gua ser um eficiente
agente deslocante de ?leos com baixa viscosidade associado ao fato de ser relativamente f?cil
de injetar e de existir grande disponibilidade de ?gua a um custo relativamente baixo de se
obter. Para o dimensionamento de um projeto de inje??o de ?gua ? necess?rio efetuar um
estudo de reservat?rio com o objetivo de se definir os v?rios par?metros necess?rios para
aumentar a efic?cia do m?todo. Para este estudo podem ser utilizados v?rios modelos
matem?ticos classificados como anal?ticos ou num?ricos.
Este trabalho tem como objetivo efetuar uma an?lise comparativa entre os resultados
apresentados por um simulador de linhas de fluxo e um simulador convencional por diferen?a
finita, que s?o dois tipos de simuladores de fluxo baseados em m?todos num?ricos, para um
modelo de um reservat?rio de petr?leo leve submetido ? inje??o de ?gua. Para tanto foram
montados dois modelos de reservat?rio, sendo um modelo heterog?neo e outro homog?neo
contendo valores m?dios das propriedades de rocha do primeiro modelo. Foram realizadas
compara??es dos resultados destes modelos considerando sempre as mesmas condi??es de
opera??o. Em seguida foram alterados alguns par?metros de fluido e de rocha em ambos os
modelos e efetuadas novamente compara??es de resultados. A partir do planejamento fatorial,
realizado para a an?lise de sensibilidade dos par?metros de reservat?rio, foram escolhidos
alguns casos para efetuar an?lise da varia??o dos par?metros operacionais escolhidos que
foram a vaz?o de inje??o de ?gua e a localiza??o dos canhoneados. Observou-se que os
resultados entre os simuladores s?o bastante similares na maioria dos casos estudados, tendo
sido encontrado diverg?ncias apenas nos casos em que h? aumento na raz?o de solubilidade
de g?s do modelo. Desta maneira foi conclu?do que o simulador convencional por diferen?as
finitas pode ser substitu?do por um simulador por linhas de fluxo em reservat?rios
semelhantes ao estudado, quando a raz?o de solubilidade possui valores baixos, sem preju?zo
aos resultados de produ??o e com menores tempos de processamento computacional. / 2020-01-01
|
20 |
Simulação de reservatórios de petróleo com geometria complexa via método dos volumes finitos e coordenadas generalizadas.CORREIA, Balbina Raquel de Brito. 27 April 2018 (has links)
Submitted by Kilvya Braga (kilvyabraga@hotmail.com) on 2018-04-27T11:04:15Z
No. of bitstreams: 1
BALBINA RAQUEL DE BRITO CORREIA - DISSERTAÇÃO (PPGEM) 2016.pdf: 6215965 bytes, checksum: 1bfd34b81d73a0bb406a5054fcdbdd3a (MD5) / Made available in DSpace on 2018-04-27T11:04:15Z (GMT). No. of bitstreams: 1
BALBINA RAQUEL DE BRITO CORREIA - DISSERTAÇÃO (PPGEM) 2016.pdf: 6215965 bytes, checksum: 1bfd34b81d73a0bb406a5054fcdbdd3a (MD5)
Previous issue date: 2016-08-16 / CNPq / A simulação numérica é uma ferramenta utilizada para modelar e estudar reservatórios de petróleo de forma a auxiliar na aplicação de métodos de recuperação suplementar. A injeção de água é o método mais utilizado na recuperação de óleo, devido ao baixo custo de processo, a disponibilidade da água e aos mecanismos de manutenção da pressão e deslocamento de óleo. O presente estudo objetivou estudar o escoamento de óleo e água em um reservatório de óleo pesado, homogêneo, com características do Nordeste brasileiro e modelagem do tipo Black oil, de formato irregular, com o intuito de avaliar o comportamento do reservatório e previsão da recuperação de óleo com a aplicação de injeção isotérmica de água. Para tanto, foi utilizado um simulador numérico, em linguagem C++, com solução das equações governantes pelo método dos volumes finitos e uso de coordenadas generalizadas, a partir de 30 anos de injeção de água, para estudar parâmetros de reservatório e operacionais e avaliar sua influência na recuperação de óleo. Foram realizadas simulações para deliberar sobre a malha do reservatório, estudo do passo de tempo mínimo utilizado nas simulações e efeito de diferentes valores de pressão inicial do reservatório. Dessa forma, foi definida uma malha com 100x50 volumes elementares e o modelo five-spot invertido para avaliar a influência de diferentes valores de permeabilidade absoluta da rocha, grau API do óleo e diferentes vazões de injeção de água, na recuperação de óleo. Foram realizadas análises da localização de poços na malha, a partir da distância entre poços injetores e produtores. A partir dos casos estudados e por meio de gráficos de Volume Poroso Injetado (VPI) versus Volume Poroso de Óleo Recuperado (VPOR), gráficos de Corte de água no tempo e mapas de saturação de água e pressão na formação produtora, ao longo tempo, foi identificado que, no processo de injeção de água, o aumento da permeabilidade absoluta influenciou negativamente e o aumento da vazão de injeção influenciou positivamente a recuperação do óleo, enquanto que o grau API não mostrou influência significativa. Em síntese, com o estudo da alocação dos poços na malha, verificou-se que os poços produtores mais distantes dos poços injetores apresentaram melhores resultados de recuperação de óleo e menor produção de água, pois, o aumento da vazão e a proximidade dos poços, aliada a maiores permeabilidades absoluta da rocha reservatório permitem a ocorrência de fingers viscosos e Breakthrough precoce, fenômenos que reduzem a eficiência do processo de injeção de água. / Numerical simulation is a tool used for modeling and studying oil reservoirs in order to aid in applying additional recovery methods. Water injection is the most common method used in oil recovery due to the low cost process, the availability of water and pressure maintenance and oil displacement mechanisms. This study aimed to study the flow of oil and water in a homogeneous heavy oil reservoir, with Brazilian Northeast characteristics and black oil model, of irregularly form, with the purpose of evaluate the reservoir behavior and prediction of oil recovery due to application of the isothermal water injection. Thus, it was used a numerical simulator, in C++ code, with solution of the governing equations by the finite volume method and the use of generalized coordinates, from 30 years of water injection to study reservoir and opertaing parameters to assess into oil recovery influence. Simulations were accomplished to deliberate on the mesh of the reservoir, minimum time step of the study used in simulations and effects of different initial pressure values of the reservoir. A mesh with 100x50 elementary volumes was defined and inverted five-spot model to evaluate the influence of different absolute values of permeability rock, oil API gravity and different flow rates of water injection on the oil recovery. Wells location analyzes were conducted in the mesh, considering the distance between injection and producers wells. Based on the case studies and using graphs Volume Porous Injected (VPI) and Volume Porous Recovered oil (VPOR), water cut graphs, in time, and reservoir pressure and water saturation maps, over time, it was identified that the water injection process, the absolute permeability increasing have influenced negatively and injection flow rate increased have influenced positively on the oil recovery, while the API gravity has not shown significant influence. In conclusion, it was identified, with the study of allocation of wells in the mesh, that most distance form producing wells of injection wells showed better results on the oil recovery and and reduced water production, therefore, with increasing the flow rate and the proximity of the wells, it combined with larger absolute permeabilities of the reservoir rock, has allowed the occurrence of viscous fingers and early Breakthrough, phenomena which reduce the efficiency of the water injection process.
|
Page generated in 0.078 seconds