A large percentage of oil and gas reservoirs in the most productive regions such as the Middle East, South America, and Southeast Asia are naturally fractured reservoirs (NFR). The major difference between conventional reservoirs and naturally fractured reservoirs is the discontinuity in media in fractured reservoir due to tectonic activities. These discontinuities cause remarkable difficulties in describing the petrophysical structures and the flow of fluids in the fractured reservoirs. Predicting fluid flow behavior in naturally fractured reservoirs is a challenging area in petroleum engineering. Two classes of models used to describe flow and transport phenomena in fracture reservoirs are discrete and continuum (i.e. dual porosity) models. The discrete model is appealing from a modeling point of view, but the huge computational demand and burden of porting the fractures into the computational grid are its shortcomings. The affect of natural fractures on the permeability anisotropy can be determined by considering distribution and orientation of fractures. Representative fracture permeability, which is a crucial step in the reservoir simulation study, must be calculated based on fracture characteristics. The diagonal representation of permeability, which is customarily used in a dual porosity model, is valid only for the cases where fractures are parallel to one of the principal axes. This assumption cannot adequately describe flow characteristics where there is variation in fracture spacing, length, and orientation. To overcome this shortcoming, the principle of the full permeability tensor in the discrete fracture network can be incorporated into the dual porosity model. Hence, the dual porosity model can retain the real fracture system characteristics. This study was designed to develop a novel approach to integrate dual porosity model and full permeability tensor representation in fractures. A fully implicit, parallel, compositional chemical dual porosity simulator for modeling naturally fractured reservoirs has been developed. The model is capable of simulating large-scale chemical flooding processes. Accurate representation of the fluid exchange between the matrix and fracture and precise representation of the fracture system as an equivalent porous media are the key parameters in utilizing of dual porosity models. The matrix blocks are discretized into both rectangular rings and vertical layers to offer a better resolution of transient flow. The developed model was successfully verified against a chemical flooding simulator called UTCHEM. Results show excellent agreements for a variety of flooding processes. The developed dual porosity model has further been improved by implementing a full permeability tensor representation of fractures. The full permeability feature in the fracture system of a dual porosity model adequately captures the system directionality and heterogeneity. At the same time, the powerful dual porosity concept is inherited. The implementation has been verified by studying water and chemical flooding in cylindrical and spherical reservoirs. It has also been verified against ECLIPSE and FracMan commercial simulators. This study leads to a conclusion that the full permeability tensor representation is essential to accurately simulate fluid flow in heterogeneous and anisotropic fracture systems. / text

<p>This research was aimed at employing the broad use of petrophysical analysis and reservoir modelling techniques to explore the petroleum resources in the sandstone units of deep marine play in the Bredasdorp Basin.</p>

Le changement climatique pourrait avoir des conséquences importantes pour les ressources en eaux et les infrastructures hydrauliques. Le dimensionnement et le fonctionnement des réservoirs devraient ainsi être modifiés en prenant en compte des scénarios de changement climatique. Un modèle de dimensionnement coût-bénéfice d'un réservoir à l'échelle du bassin versant est appliqué en Grèce afin d'évaluer le coût de l'incertitude sur le climat futur et les dommages du changement climatique. Dans cette étude de cas, le coût de l'erreur est faible, et l'adaptation n'est pas efficace. Une méthodologie sur toute la région méditerranéenne, avec une modélisation générique à l'échelle des bassins versant est ensuite développée. Les réseaux de réservoirs et les liens réservoirs-demandes sont reconstruits et le fonctionnement coordonné des réseaux de réservoirs est déterminé, en utilisant uniquement des données disponibles à l'échelle globale. La méthodologie de reconstruction des liens est appliquée à l'irrigation et validée qualitativement sur l'Algérie. Le changement de fiabilité, avec adaptation des règles opérationnelles, sous changement climatique, semble être plus influencé par les changements de ruissellement que par les changements de demande. Les changements obtenus pour le Nil, l'Europe et le Moyen Orient ne sont pas très marqués, alors que les pays d'Afrique du Nord sous influence méditerranéenne comme la Tunisie ou l'Algérie voient une diminution importante de la fiabilité des apports d'eau pour l'irrigation / Climate change could affect water resources and hydraulic infrastructures seriously. Dimensioning and operation of reservoirs should therefore be modified according to climatic change scenarios. To assess the effect of climate uncertainty on reservoir volumes dimensioning using cost-benefit analysis, a model of reservoir dimensioning at the river basin scale is applied in Greece. For the case study, there is no cost of error and adaptation seems to be inefficient. A methodology at the scale of the Mediterranean region with a generic modeling at the river basin level is developed. Reservoirs networks and reservoirs-demands links are reconstructed and coordinated reservoirs networks operation is determined, using only globally available data. The link reconstruction methodology is applied on irrigation demand and validated qualitatively on Algeria. Change in reliability with adaptation of reservoir operating rules under climate change over the Mediterranean region is then assessed. Reliability changes seem to be more influenced by inflow changes than by demand changes. They are not important for the Nile basin and the European and Middle East sub-regions, while in North African countries with a more pronounced Mediterranean influence, like Tunisia or Algeria, reliability decrease can be significant

Acidic atmospheric deposition and acidification of soil and water on the Earth's surface, due to emissions of sulfur and nitrogen into the atmosphere, have led to drastic changes in the composition of surface waters and their biota in many regions of the world over the last century. The number of species and biomass of phytoplankton, zooplankton and benthos were reduced, or some components (zooplankton, zoobenthos, fish) became extinct. In the Jizera Mountains (Northern Bohemia, Czech Republic), the man-made acidification has always been combined with a natural acidity (dystrophy) of waters, caused by a high amount of organic acids. Despite a strong recovery of water chemistry from acidification, that has started in the 1990s, biological recovery is delayed and much more complex. This master thesis is a study of the succession of zooplankton (crustaceans) in mountain reservoirs Souš, Bedřichov and Josefův Důl after decades of strong acidification. Biological recovery from acidification has been in progress differently in the drinking water reservoir Souš, which has long been limed, in the Bedřichov reservoir with naturally high content of organic material, and in the drinking water reservoir Josefův Důl, which is the largest and deepest one and which was most affected by acidification. Recovery of...

Seismic inversion using a global optimization algorithm is a non-linear, model-driven process. It yields an optimal solution of the cost function – reflectivity/acoustic impedance, when prior information is sparse. The inversion result offers detailed interpretations of thin layers, internal stratigraphy, and lateral continuity and connectivity of sand bodies. This study compared two stable and robust global optimization techniques, Simulated Annealing (SA) and Basis Pursuit Inversion (BPI) as applied to post-stack seismic data from the Gulf of Mexico. Both methods use different routines and constraints to search for the minimum error energy function. Estimation of inversion parameters in SA is rigorous and more reliable because it depends on prior knowledge of subsurface geology. The BPI algorithm is a more robust deterministic process. It was developed as an alternative method to incorporating a priori information. Results for the Gulf of Mexico show that BPI gives a better stratigraphic and structural actualization due to its capacity to delineate layers thinner than the tuning thickness. The SA algorithm generates both absolute and relative impedances, which provide both qualitative and quantitative characterization of thin-bed reservoirs.

The object of this dissertation is to describe the influence of water works on the outflow from a watershed through the Hydrologic Modelling System Hec HMS. It is a direct application to the particular watershed of the Bílský Stream. In the theoretical part about relevant literature, solutions to the topics related to this issue are found. It focuses especially on the water balance in the watershed; the outflow from the watershed and other factors by which the watershed is influenced; extreme flows and flood activity with appropriate security steps such as water basins. At the end of the part on the literature, there are five different systems for creating hydrologic models with the specialisation on the Hec HMS model. The practical part is about preparing input data for the hydrologic model and its subsequent creation. Particular runoff from different N-year precipitation (N = 2, 10, 50 and 100) are compared. Two hydrologic models have been created for comparison, one with the watershed without a reservoir and the second one with a reservoir included. The resultant part is about watching flows, volumes of runoffs and the tranformation of the flood wave in a reservoir between N-year precipitation and two different models of watershed.

Les modèles génétiques de réservoirs sont construits par la simulation des principaux processus de sédimentation dans le temps. En particulier, les modèles tridimensionnels de systèmes chenalisés méandriformes peuvent être construits à partir de trois processus principaux : la migration du chenal, l’aggradation du système et les avulsions, comme c’est réalisé dans le logiciel Flumy pour les environnements fluviatiles. Pour une utilisation opérationnelle, par exemple la simulation d'écoulements, ces simulations doivent être conditionnées aux données d'exploration disponibles (diagraphie de puits, sismique, …). Le travail présenté ici, basé largement sur des développements antérieurs, se concentre sur le conditionnement du modèle Flumy aux données de puits.Deux questions principales ont été examinées au cours de cette thèse. La première concerne la reproduction des données connues aux emplacements des puits. Cela se fait actuellement par une procédure de "conditionnement dynamique" qui consiste à adapter les processus du modèle pendant le déroulement de la simulation. Par exemple, le dépôt de sable aux emplacements de puits est favorisé, lorsque cela est souhaité, par une adaptation des processus de migration ou d'avulsion. Cependant, la manière dont les processus sont adaptés peut générer des effets indésirables et réduire le réalisme du modèle. Une étude approfondie a été réalisée afin d'identifier et d'analyser les impacts indésirables du conditionnement dynamique. Les impacts ont été observés à la fois à l'emplacement des puits et dans tout le modèle de blocs. Des développements ont été réalisés pour améliorer les algorithmes existants.La deuxième question concerne la détermination des paramètres d’entrée du modèle, qui doivent être cohérents avec les données de puits. Un outil spécial est intégré à Flumy - le "Non-Expert User Calculator" (Nexus) - qui permet de définir les paramètres de simulation à partir de trois paramètres clés : la proportion de sable, la profondeur maximale du chenal et l’extension latérale des corps sableux. Cependant, les réservoirs naturels comprennent souvent plusieurs unités stratigraphiques ayant leurs propres caractéristiques géologiques. L'identification de telles unités dans le domaine étudié est d'une importance primordiale avant de lancer une simulation conditionnelle avec des paramètres cohérents pour chaque unité. Une nouvelle méthode de détermination des unités stratigraphiques optimales à partir des données de puits est proposée. Elle est basée sur la Classification géostatistique hiérarchique appliquée à la courbe de proportion verticale (VPC) globale des puits. Les unités stratigraphiques ont pu être détectées à partir d'exemples de données synthétiques et de données de terrain, même lorsque la VPC globale des puits n'était pas visuellement représentative. / Process-based reservoir models are generated by the simulation of the main sedimentation processes in time. In particular, three-dimensional models of meandering channelized systems can be constructed from three main processes: migration of the channel, aggradation of the system and avulsions, as it is performed in Flumy software for fluvial environments. For an operational use, for instance flow simulation, these simulations need to be conditioned to available exploration data (well logging, seismic, …). The work presented here, largely based on previous developments, focuses on the conditioning of the Flumy model to well data.Two main questions have been considered during this thesis. The major one concerns the reproduction of known data at well locations. This is currently done by a "dynamic conditioning" procedure which consists in adapting the model processes while the simulation is running. For instance, the deposition of sand at well locations is favored, when desired, by an adaptation of migration or avulsion processes. However, the way the processes are adapted may generate undesirable effects and could reduce the model realism. A thorough study has been conducted in order to identify and analyze undesirable impacts of the dynamic conditioning. Such impacts were observed to be present both at the location of wells and throughout the block model. Developments have been made in order to improve the existing algorithms.The second question is related to the determination of the input model parameters, which should be consistent with the well data. A special tool is integrated in Flumy – the Non Expert User calculator (Nexus) – which permits to define the simulation parameters set from three key parameters: the sand proportion, the channel maximum depth and the sandbodies lateral extension. However, natural reservoirs often consist in several stratigraphic units with their own geological characteristics. The identification of such units within the studied domain is of prime importance before running a conditional simulation, with consistent parameters for each unit. A new method for determining optimal stratigraphic units from well data is proposed. It is based on the Hierarchical Geostatistical Clustering applied to the well global Vertical Proportion Curve (VPC). Stratigraphic units could be detected from synthetic and field data cases, even when the global well VPC was not visually representative.

Neste trabalho, descrevemos vários protocolos para a geração de estados estacionários não clássicos, suportados principalmente pela engenharia de hamiltonianos seletivos Jaynes-Cummings, e de reservatórios atômicos. Começamos apresentando um protocolo para engenhar interações seletivas lineares e não lineares do tipo Jaynes-Cummings como também simulações numéricas para comprovar a eficácia de nosso esquema. Analisamos também como aplicar essas interações seletivas à preparação e proteção de estados de Fock estacionários via reservatório atômico. Esta estratégia combina a ação dos mecanismo de amortecimento da cavidade com os de um reservatório atômico engenhado para conduzir uma distribuição térmica inicial a um estado de Fock estacionário. A mesma técnica pode ser utilizada para fatiar as distribuições de probabilidade no espaço de Fock, permitindo assim a preparação de uma variedade de estados de equilíbrio não clássicos. Também apresentamos um protocolo para a engenharia de interações upper-bound e sliced Jaynes-Cummings e anti-Jaynes-Cummings na eletrodinâmica quântica de cavidade. No Hamiltoniano upper-bound, a interação átomo-campo está confinada a um subespaço de Fock com estados que vão desde &Iota;0&gt; até &Iota;4&gt; enquanto que no Hamiltoniano sliced vão desde &Iota;M&gt; até &Iota;M + 4&gt;. Mostramos como construir Liouvillianos upper-bound independentemente da engenharia do Hamiltoniano upper-bound. Os Hamiltonianos e Liouvillianos upper-bound e sliced podem ser usados, entre outras aplicações, para gerar estados de Fock estacionários no modo da cavidade e para a implementação de um dispositivo de tesoura quântica para truncagem de estado óptico. Finalmente, propomos um esquema para a preparação de estados emaranhados estacionários em redes bosônicas dissipativas. Descrevemos a sua aplicação em um sistema de cavidades acopladas interagindo com um reservatório construído por átomos de três níveis. Os emblemáticos estados Bell e NOON, e estados multipartites (tipo W) podem ser produzidos com alta fidelidade e pureza. / In this work, we describe various protocols for the generation of nonclassical steady-state, supported mainly by the engineering selective Hamiltonian Jaynes-Cummings-type, and atomics reservoirs. We started presenting a framework to engineer nonlinear selective JaynesCummings-type interactions with numerical simulations to prove the effectiveness of our scheme. We further analyses how to apply these selective interactions to the preparation and protection of steady Fock states via atomic reservoir. This strategy combines the action of cavity damping mechanisms with that of an engineered atomic reservoir to drive an initial thermal distribution to a Fock equilibrium state. The same technique can be used to slice probability distributions in the Fock space, thus allowing the preparation of a variety of non-classical equilibrium states. Also we present a protocol to engineer upper-bound and sliced Jaynes-Cummings-type and anti-Jaynes-Cummings-type Hamiltonians in cavity quantum electrodynamics. In the upper-bounded Hamiltonians, the atom-field interaction is confined to a subspace of Fock states ranging from &Iota;0&gt; up to &Iota;4&gt;, while in the sliced interaction the Fock subspace ranges from &Iota;M&gt; up to &Iota;M + 4&gt;. We also show how to build upper-bounded and sliced Liouvillians irrespective of engineering Hamiltonians. The upper-bounded and sliced Hamiltonians and Liouvillians can be used, among other applications, to generate steady Fock states of a cavity mode and for the implementation of a quantum-scissors device for optical state truncation. Finally we propose a scheme for the preparation of steady entanglements in bosonic dissipative networks. We describe its implementation in a system of coupled cavities interacting with an engineered reservoir built up of three-level atoms. Emblematic bipartite (Bell and NOON) and multipartite (W -class) states can be produced with high fidelity and purity.

A avaliação ecotoxicológica dos sedimentos dos reservatórios de Barra Bonita e Salto Grande foi realizada através de testes de toxicidade aguda e crônica com o sedimento total e o solubilizado, com os organismos-teste Chironomus xanthus, Daphnia similis, Ceriodaphnia dubia, Vibrio fisheri e Spirillum volutans, além de análises físicas (pH, EH e \'O IND.2\') e químicas (fósforo, nitrogênio, carbono orgânico total, sulfetos e amônia e metais potencialmente disponíveis). A concentrações médias de matéria orgânica e fósforo obtidas para os sedimentos dos reservatórios de Barra Bonita e Salto Grande foram elevadas, e condizentes com a carga de matéria orgânica e com as baixas concentrações de oxigênio dissolvido e de potencial redox. Em relação aos metais, os resultados revelaram que, para o reservatório de Barra Bonita, eles podem estar influenciando a toxicidade detectada através dos testes de toxicidade. Em Salto Grande, os resultados indicaram que os sulfetos estão atuando como fase controladora dos metais, mantendo-os indisponíveis nos sedimentos. Para esse reservatório a principal causa da toxicidade foi a acidez. O estudo de Avaliação e Identificação da Toxicidade realizado com as amostras de sedimento dos reservatórios de Barra Bonita, Salto Grande e Rasgão mostrou que os possíveis compostos tóxicos responsáveis pela toxicidade são metais (Barra Bonita); amônia (Salto Grande e Rasgão); compostos ácidos voláteis e compostos orgânicos não iônicos (Rasgão). O tratamento com a resina zeolita foi eficiente na remoção da amônia e redução da toxicidade do sedimento do reservatório de Rasgão, confirmando dessa forma, a amônia como o principal composto tóxico. O estudo de Avaliação e Identificação da Toxicidade deve ser incorporado nos programas de controle, monitoramento e gestão dos recursos hídricos, devido a importância da identificação dos compostos responsáveis pela toxicidade. / An ecotoxicological evaluation of the sediments of Barra Bonita and Salto Grande reservoirs was performed by carrying out acute and chronic toxicity tests with both the total sediment and elutriate using Chironomus xanthus, Daphnia similis, Ceriodaphnia dubia, Vibrio fisheri and Spirillum volutans as test-organisms, as well as physical (pH, EH e \'O IND.2\') and chemical analysis (phosphorus, nitrogen, total organic carbon, sulphide, ammonium and potentially available metals). The mean concentrations of organic matter and phosphorus obtained for the sediments of Barra Bonita and Salto Grande reservoirs were high and in agreement with the organic matter loading, low dissolved oxygen concentrations and redox potential. In relation to metals, the results revealed that in Barra Bonita reservoir they might be responsible for the toxicity detected. For Salto Grande, the results indicated that sulphides act as metal controlling phase keeping them unavailable in the sediments. The main cause of the toxicity in this reservoir was acidity. The Toxicity Identification and Evaluation (TIE) carried out with the sediments of Barra Bonita, Salto Grande and Rasgão have shown that the probable toxic compounds responsible for toxicity are metals (Barra Bonita); ammonium (Salto Grande and Rasgão); volatile acid compounds and non-ionic compounds (Rasgão). The treatment with zeolite was efficient in removing ammonium and reducing toxicity in the sediment of Rasgão reservoir, thus confirming ammonium as the main toxic compound. The Toxicity Identification and Evaluation approach must be incorporated in the control, monitoring and management of water resources, due to the relevance of identifying the compounds responsible by the toxicity.

Os problemas de escassez hídrica enfrentados pela região Nordeste do Brasil ocorrem, principalmente, devido às condições climáticas, caracterizadas pela má distribuição das chuvas tanto temporalmente - a maior parte da precipitação anual se concentra em poucos meses - quanto espacialmente. A alta taxa de evaporação da região e a estrutura geológica do solo, predominantemente cristalino, são fatores que contribuem para agravar o problema. Fica evidenciada, portanto, a necessidade de a operação dos sistemas de recursos hídricos ser otimizada, propiciando assim, o seu melhor aproveitamento, com o menor custo para a sociedade. O presente trabalho estuda a operação otimizada dos reservatórios que abastecem a região metropolitana de Fortaleza, no Estado do Ceará, considerando a evaporação. O problema foi tratado através de um procedimento híbrido, proposto recentemente, de algoritmo genético e programação linear. O método permitiu que regras operacionais fossem extraídas sem a necessidade de fixá-las a priori, considerando diferentes condições de importe hídrico e possibilidades hidrológicas para evidenciar a robustez do método. / The problems of water shortage in the Northeast area of Brazil, are mainly due to the weather conditions, characterized by scattered rainfall depending upon the time of the year - the highest annual precipitation is concentrated in a few months - as well as the location. Very high evaporation rates in the region and the geological structure of the soil, mainly of crystalline origin, are factors that worsen shortage of water. Thus, there need for optimal operation of water resources systems, so as to obtain highest benefit at low costs for the society. The present study performs optimized operation of the Fortaleza (Ceará) metropolitan area water supply reservoirs with special attention to water losses by evaporation. The problem has been handled through a recently proposed hybrid procedure, genetic algorithm and linear programming. The method permitted extraction of operational rules without having to hypothesize their structure \"a priori\". Further, it was applied to Fortaleza water supply under different hydrologic conditions and those of inter-basin water transfers to verify the strength of the method employed.