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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
681

A carbonate reservoir model for Petersilie field in Ness County, Kansas: effective waterflooding in the Mississippian System

McCaw, 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.
682

Mesoporous magnesium carbonate : Synthesis, characterization and biocompatibility

Frykstrand Ångström, Sara January 2016 (has links)
Mesoporous materials constitute a promising class of nanomaterials for a number of applications due to their tunable pore structure. The synthesis of most mesoporous materials involves a surfactant liquid crystal structure to form the pores. As well as the many advantages associated with this method of synthesis, there are disadvantages such as high production costs and a substantial environmental impact which limit the possibilities for large scale production. Therefore there is a need for other synthesis routes. The aim of the work described herein was to contribute to this field by developing a synthesis route that does not rely on surfactants for pore formation. A mesoporous magnesium carbonate material was therefore formed by self-assemblage of the particles around carbon dioxide gas bubbles, which functioned as pore templates. It was also possible to vary the pore diameter between 3 and 20 nm. The biocompatibility of the formed magnesium carbonate material was evaluated in terms of in vitro cytotoxicity and hemocompatibility, in vivo skin irritation and acute systemic toxicity. The results from the in vitro cytotoxicity, in vivo skin irritation and acute systemic toxicity test using a polar extraction vehicle showed that the material was non-toxic. While signs of toxicity were observed in the acute systemic toxicity test using a non-polar solvent, this was attributed to injection of particles rather than toxic leachables. In the in vitro hemocompatibility test, no hemolytic activity was found with material concentrations of up to 1 mg/ml. It was further shown that the material had anticoagulant properties and induced moderate activation of the complement system. The anticoagulant properties were ascribed to uptake of Ca2+. Finally, the ability of the material to increase the dissolution rate of the poorly soluble drug itraconazole was analyzed.  Itraconazole was dissolved up to 23 times faster from the magnesium carbonate pores than when the free drug was used. The release rate from the delivery vehicle was dependent on the pore diameter. The work presented herein is expected to be useful for the development of alternative synthesis routes for mesoporous materials and also for encouraging the development of biomedical applications for these materials.
683

Geometry and nature of modern and ancient mass transport deposits worldwide

Singh, Kadira Analisa, 1986- 28 October 2010 (has links)
Mass transport deposits form a significant portion of the rock record in both modern and ancient basins. Their geometry, composition, distribution and genesis are poorly understood, making it difficult to predict anything about these deposits in assessing subsurface basin stratigraphy or modern seafloor hazards. A tremendous effort has been made in the last few years to characterize and better understand seafloor failures in numerous margins of the world. These mass failures have triggered the interests of geologists, particularly in the oil and gas industry, as they can form prominent seals and reservoirs. To increase our knowledge base of mass transport complexes (MTCs), the characteristics of 259 siliciclastic deposits worldwide, were analyzed in terms of their volume, area, length, thickness, lithology, and tectonic settings. In some instances, MTCs were geo-referenced and digitized into ArcGIS and their dimensions were calculated. These data reveal several interesting points and suggest a number of statistically significant predictive relationships. Sand-rich mass transport deposits show a propensity to be short and thick. Muddy MTCs show a propensity to be longer and thinner. The highest number and largest volume of clastic mass transport deposits occur along passive margins. These mega-MTCs are typically muddy with lengths up to 800 km and volumes up to 5000 km3. Sandy and gravelly Quaternary-age MTCs show maximum lengths of less than 300 km and with volumes less than 2000 km3. Pre-Quaternary MTCs are systematically under-documented in literature, but known occurrences are found in passive, active and convergent margins. The largest (30,000 to 40,000 sq km) occur along the older Tertiary margin of West Africa. To date, 41 separate mass transport deposits composed dominantly of carbonate material have been identified in literature. The most extensive and voluminous (7000 km3) carbonate mass transport complexes occur in the Citronens Fjord, Offshore Greenland. They are 200m thick, Silurian-age mega-breccias that were deposited in a convergent margin setting. On comparison carbonate MTCs tend to show longer flows with coarser grain sizes, while clastics show coarser grained deposits to be of more limited length. The Mad Dog area, Gulf of Mexico is a region of active salt tectonics and mass transport processes. Consequently, it was selected to form a focus study area to test the relationships developed during this project. MTCs in this region were grouped into four main types based on their size, geomorphology and internal structure. Their geometries indicate they are comparable to MTCs found offshore Oregon and New Jersey and are most likely muddy in nature. / text
684

Compréhension des phénomènes interfaciaux dans les composites à base de charges carbonate de calcium précipité : influence du traitement de surface et du procédé de mise en œuvre

Morel, Floriane 10 December 2010 (has links) (PDF)
Ce travail a eu pour objectif la création de matériaux composites à base de nanocharges de carbonate de calcium. L'étude des phénomènes interfaciaux qui régissent ces systèmes, ainsi que leurs impacts sur les propriétés fonctionnelles du matériau et plus particulièrement des propriétés de transport, ont été réalisées. Pour ce faire, nous avons considéré deux matrices polymères de nature chimique différente : le polylactide et le polyfluore de vinylidène. Les nanocomposites ont été élaborés par deux voies de mise en œuvre : la voie fondu et la voix solvant. Une analyse fine des relations structure/morphologie/propriétés des composites a été réalisée. Nous avons mis en évidence, quelle que soit la matrice polymère choisie, l'importance du traitement de surface des charges afin d'améliorer leurs états de dispersion dans le matériau et d'augmenter la qualité de l'interface charge/polymère. Ces paramètres ont été corrélés aux propriétés de transport de ces matériaux composites.
685

The regulation of intestinal bicarbonate secretion by marine teleost fish

Whittamore, Jonathan Mark January 2008 (has links)
In seawater, drinking is a fundamental part of the osmoregulatory strategy for teleost fish, and presents a unique challenge. The intestine has an established role in osmoregulation, and its ability to effectively absorb fluid from imbibed seawater is crucial to compensating for water losses to the surrounding hyperosmotic environment. Alongside solute-linked water transport (driven by NaCl cotransport), intestinal bicarbonate (HCO3-) secretion also benefits fluid absorption directly (via apical Cl-/HCO3- exchange), and indirectly through the formation of calcium carbonate (CaCO3) thus removing the osmotic influence of Ca2+ within the gut fluid. For the European flounder (Platichthys flesus), elevated luminal Ca2+ has proven to be a specific, potent stimulator of HCO3- secretion both in vitro and in vivo where these actions are presumably modulated by an extracellular Ca2+-sensing receptor (CaR). The focus of this work was to learn more about how intestinal HCO3- secretion is regulated, the role of Ca2+, and more specifically the CaR. To achieve this, in vitro ‘gut sac’ experiments investigated how luminal Ca2+ influenced HCO3- secretion, and associated ion and fluid transport. Contrary to expectation, increasing Ca2+ from 5 to 20 mM did not stimulate HCO3- secretion. In an attempt to elucidate the role of CaCO3 precipitation in fluid absorption, and further explore the physiological implications of HCO3- secretion, the intestine was perfused in vivo with salines containing varying concentrations of Ca2+ (10, 40 and 90 mM). The production and secretion of HCO3-, in addition to CaCO3 formation increased accordingly with Ca2+, and was associated with a dramatic 25 % rise in the fraction of fluid absorbed by the gut. Additional in vitro experiments, utilising the Ussing chamber, helped establish some of the characteristics of intestinal HCO3- secretion by the euryhaline killifish (Fundulus heteroclitus), but was unresponsive to elevated mucosal Ca2+. Further attempts to potentiate the activity of the CaR, and application of the receptor agonists gadolinium (Gd3+) and neomycin, failed to produce responses consistent with the effect of Ca2+ observed previously, either in vitro or in vivo. With no evidence supporting a direct role for an extracellular, intestinal CaR in HCO3- secretion it was argued that secretion would be principally regulated by two factors, the ability of the epithelia to generate high levels of intracellular HCO3- and the rate of CaCO3 formation.
686

Émergence de la production carbonatée pélagique au Jurassique moyen (180-160 Ma) : la conquête des océans par les coccolithophoridés du genre Watznaueria / Pelagic carbonate production emergence during the Middle Jurassic (180-160 Ma) : the conquest of the oceans by the coccolithophorid genus Watznaueria

Suchéras-Marx, Baptiste 12 April 2012 (has links)
Les coccolithophoridés sont des algues marines photosynthétiques et planctoniques qui produisent des plaques micrométriques de carbonate de calcium (CaCO3) appelés coccolithes. Ces algues sont apparues il y 210 Ma et produisent actuellement la majeure partie du CaCO3 dans les océans modernes, jouant ainsi un rôle majeur dans le cycle du carbone. Cependant, l’émergence de la production de CaCO3 océanique par les coccolithophoridés au cours du Jurassique, ainsi que son impact sur le cycle du carbone, restent très mal compris. Cette étude s’est donc focalisée sur une période du Jurassique Moyen (Bajocien inférieur, -170 Ma) enregistrant la diversification de Watznaueria, un genre de coccolithophoridé qui a ensuite dominé la production de CaCO3 océanique pendant plus de 80 Ma. L’analyse des assemblages de coccolithes du Jurassique Moyen du Portugal et du sud de la France, réalisée à l’aide d’une méthode de reconnaissance automatique appliquée pour la première fois aux coccolithes du Jurassique, a permis de quantifier l’importance de cette période de diversification sur la production de CaCO3 pélagique. En outre, la durée de cet intervalle clé a été réévaluée grâce à l’analyse cyclostratigraphique des séries sédimentaires du Sud de la France. Les variations de production de CaCO3 pélagique ainsi reconstituées ont été comparées aux perturbations du cycle du carbone enregistrées par les rapports des isotopes du carbone, et indiquent un lien probable avec une augmentation marquée de la fertilité des océans. Par ailleurs, l’analyse paléontologique montre que cette diversification correspond à l’apparition successive de différentes espèces vraisemblablement opportunistes du genre Watznaueria. Enfin, les flux obtenus de CaCO3 pélagiques, largement inférieurs à ceux observés dans les océans actuels, semblent insuffisants pour avoir eu une influence significative sur le cycle global du carbone du Jurassique Moyen. / Coccolithophorids are photosynthetic and planktonic marine algae that produce micrometric calcium carbonate (CaCO3) platelets called coccoliths. These algae appeared about 210 Ma ago and produce today most of the CaCO3 in the modern oceans, hence playing a major role in the carbon cycle. Nevertheless, the onset of oceanic CaCO3 production by these organisms during the Jurassic and its impact on carbon cycling remain poorly understood. This study therefore focused on the Middle Jurassic interval (Early Bajocian, -170 Ma) which records the diversification of Watznaueria, an evolutionary important coccolith genus that subsequently dominated oceanic CaCO3 production for more than 80 Myr. The analysis of coccolith assemblages from the Middle Jurassic of southern France and Portugal, based on an automaticcoccolith recognition device used for the first time on Jurassic coccoliths, allowed quantifying the impact of this diversification on CaCO3 production. In addition, the duration of this key interval has been revaluated by the cyclostratigraphic analysis of sedimentary strata from southern France. The reconstructed changes in CaCO3 production were compared to carbon cycle perturbations recorded by carbon isotope ratios and indicate a probable link with a marked increase of ocean fertility. Besides, paleontological analyses show that this diversification episode correspond to the successive appearance of different, probably opportunistic Watznaueria species. The obtained fluxes of pelagic CaCO3 production, by far lower than those recorded in modern oceans, seems too low to have significantly impacted theMiddle Jurassic carbon cycle.
687

Functional nanocomposites for advanced fuel cell technology and polygeneration

Raza, Rizwan January 2011 (has links)
In recent decades, the use of fossil fuels has increased exponentially with a corresponding sharp increase in the pollution of the environment. The need for clean and sustainable technologies for the generation of power with reduced or zero environment impact has become critical. A number of attempts have been made to address this problem; one of the most promising attempts is polygeneration. Polygeneration technology is highly efficient and produces lower emissions than conventional methods of power generation because of the simultaneous generation of useable heat and electrical power from a single source of fuel. The overall efficiency of such systems can be as high as 90%, compared to 30-35% for conventional single-product power plants. A number of different technologies are available for polygeneration, such as micro gas turbines, sterling engines, solar systems, and fuel cells. Of these, fuel cell systems offer the most promising technology for polygeneration because of their ability to produce electricity and heat at a high efficiency (about 80%) with either low or zero emissions. Various fuel-cell technologies can be used in polygeneration systems. Of these, solid oxide fuel cells (SOFCs) are the most suitable because they offer high system efficiency for the production of electricity and heat (about 90%) coupled with low or zero emissions. Compared to other types of fuel cells, SOFCs have fuel flexibility (direct operation on hydrocarbon fuels, such as biogas, bio-ethanol, bio-methanol, etc.) and produce high-quality heat energy. The development of polygeneration systems using SOFCs has generally followed one of two approaches. The first approach involves the design of a SOFC system that operates at a temperature of 850 oC and uses natural gas as a fuel. The second approach uses low-temperature (generally 400-600 oC) SOFC (LTSOFC) systems with biomass, e.g., syngas or liquid fuels, such as bio-methanol and bio-ethanol. The latter systems have strong potential for use in polygeneration. High-temperature SOFCs have obvious disadvantages, and challenges remain for lowering the cost to meet commercial interest. The SOFC systems need lower operating temperatures to reduce their overall costs. This thesis focuses on the development of nanocomposites for advanced fuel-cell technology (NANOCOFC), i.e., the next generation SOFCs, which are low-temperature (400-600 oC), marketable, and affordable SOFCs. In addition, new concepts that pertain to fuel-cell science and technology—NANOCOFC (www.nanocofc.com)—are explored and developed. The content of this thesis is divided into five parts: In the first part of this thesis (Papers 1-5), the two-phase nanocomposite electrolytes, viz. ceria-salt and ceria-oxide, were prepared and studied using different electrochemical techniques. The microstructure and morphology of the composite electrolytes were characterised using XRD, SEM and TEM, and the thermal analysis was conducted using DSC. An ionic conductivity of 0.1 S/cm was obtained at 300 ºC, which is comparable to that of conventional YSZ operating at 1000 ºC. The maximum output power density was 1000 mW/cm2 at 550 oC. A co-doped ceria-carbonate was also developed to improve the ionic conductivity, morphology, and performance of the electrolyte. In the second part of this thesis (Papers 7-9), composite electrodes that contained less or no nickel (Ni) were developed for a low-temperature SOFC. All of the elements were highly homogenously distributed in the composite electrode, which resulted in high catalytic activity and good ASOFC performance. The substitution of Ni by Zn in these electrodes could reduce their cost by a factor of approximately 25. In the third part of this thesis (Papers 10), an advanced multi-fuelled solid-oxide fuel cell (ASOFC) with functional nanocomposites (electrolytes and electrodes) was developed. Several different types of fuel, such as gaseous (hydrogen and biogas) and liquid fuels (bio-ethanol and bio-methanol), were tested. Maximum power densities of 1000, 300, 600, and 550 mW/cm2 were achieved with hydrogen, bio-gas, bio-methanol, and bio-ethanol, respectively, in the ASOFC. Electrical and total efficiencies of 54% and 80%, respectively, were achieved when the single cell was used with hydrogen. The fourth part of this thesis (Papers 11) concerns the design of a 5 kW ASOFC system based on the demonstrated advanced SOFC technology. A polygeneration system based on a low-temperature planar SOFC was then designed and simulated. The efficiency of the overall system was approximately 80%. The fifth part of this thesis (Paper 12) describes a single-layer multi-fuelled electrolyte-free fuel cell that is a revolutionary innovation in renewable-energy sources. Conventional fuel cells generate electricity by ion transport through the electrolyte. However, this new device works without an electrolyte, and all of the processes occur at particle surfaces in the material. Based on a theoretical calculation, an additional 18% enhancement of the fuel cell’s efficiency will be achieved using this new technology compared to the conventional technologies. Our developed ASOFC systems with functional nanocomposites offer significant advantages in reducing the operational and capital costs for the production of power and heat by using different fuels based on the fuel-cell technology. ASOFC systems can be used for polygeneration with renewable fuels (i.e., biomass fuels) at high efficiency as a sustainable solution to energy generation in our society. The results have been achieved for this thesis work has demonstrated an advanced fuel cell technology. / <p>QC 20111213</p>
688

Les horizons d'accumulations carbonatées en Champagne-Ardenne : répartition régionale, caractérisation et impact sur les transferts hydriques / Carbonate accumulation horizons in Champagne-Ardenne : regional distribution, characterization and impact on hydric transfers

Linoir, Damien 24 June 2014 (has links)
Les horizons d'accumulations carbonatées (HAC) de Champagne sont des horizons particuliers présents de manière non systématique dans les profils de sol directement sous l'horizon organo-minéral. Bien que des travaux antérieurs se soient déjà attachées à l'étude de ces structures particulières, certaines questions restent encore en suspens, notamment en ce qui concerne leur localisation dans le cadre régional, leur caractérisation par rapport aux autres horizons du profil et la quantification de leur rôle dans les transferts hydriques. Leur localisation sur le terrain n'étant pas réalisable méthodes de prospection habituelles (pénétrométrie dynamique, tarière), les zones de localisation préférentielle des HAC ont été déterminées par une exploration bibliographique. Des analyses en laboratoire ont été conduites sur des échantillons prélevés sur un site pilote représentatif, le Mont du Ménil (08). En plus des analyses géochimiques et de la colorimétrie, les échantillons prélevés tout au long des profils ont subi des analyses pétrophysiques habituellement utilisées dans la caractérisation des pierres en œuvre (porosité totale à l'eau, porosimétrie mercure, cinétiques d'absorptions capillaires et d'évaporation). Ces analyses montrent que les HAC sont bien différents des horizons sus et sous-jacents. Ce sont des niveaux présentant une forte porosité qui va de pair avec leur induration plus faible contrairement à ce qui est généralement admis dans la bibliographie. Les HAC présentent également des micromorphologies différentes des autres horizons du profil pédologique ce qui justifient les réseaux poreux différents identifiés. L'étude des transferts hydriques en laboratoire montre également que ces réseaux poreux différents sont responsables de transferts hydriques plus rapides dans les HAC que dans leurs grèzes d'accueil. Il apparaît donc que contrairement à ce qui est généralement avancé dans la littérature, les HAC champardennais ne semblent pas faire obstacle aux transferts hydriques mais semble au contraire les favoriser. Ce phénomène pourrait avoir des conséquences agronomiques importantes favorisant le drainage et les remontées capillaires. / Carbonate accumulation horizons (CAH) are structures un-systematically present in Champagne-Ardenne soils (NE of France) and are localized directly under de rendic leptosol. They have already been studied but their regional repartition, characterization compare to other soils horizons and impact on water transfers remain unknown. On the field, CAH cannot be directly localized by currently prospection methods. Preferential location areas have been determined by literature analyze. Geochemistry, colorimetry and petrophysical analyzes (total water porosity, mercury porosimetry, absorption en evaporation kinetics tests) have been applied on samples took on a representative site : Mont du Ménil. These analyses have shown that CAH present a high porosity linked to their weak induration contrary to what is generally advanced in the literature. The micromorphology of CAH is different from others horizons that induces porous network différences. Laboratory water transfers study links these porous network differences to faster water transfers measured for CAH contrary to the others horizons. CAH of Champagne do not impede water transfers contrary to what is generally fund into the literature but seems to favor them. This phenomenon could have important agronomic implications favouring draining and capillary rises.
689

[en] HYDROMECHANICAL SIMULATION OF A CARBONATE PETROLEUM RESERVOIR USING PSEUDO-COUPLING / [pt] SIMULAÇÃO HIDROMECÂNICA DE RESERVATÓRIO CARBONÁTICO DE PETRÓLEO ATRAVÉS DE PSEUDOACOPLAMENTO

FLAVIA DE OLIVEIRA LIMA FALCAO 27 June 2014 (has links)
[pt] Reservatórios carbonáticos respondem por mais de 50 por cento da produção mundial de hidrocarbonetos. No Brasil, ganharam mais importância com o descobrimento do Pré-Sal, em 2006. A principal ferramenta de previsão e gerenciamento de reservatórios é a simulação numérica que, tradicionalmente, tem na compressibilidade do poro o único parâmetro geomecânico. Normalmente é adotado apenas um valor, mantido constante, deste parâmetro para todo o reservatório. Porém, a rocha-reservatório sofre deformações durante a explotação do campo, as quais induzem redução da porosidade e permeabilidade. Enquanto o primeiro efeito não é bem representado pela compressibilidade, o segundo não sofre qualquer alteração. Além disso, cada fácies tem um comportamento tensão versus deformação diferente. Por isso a importância de se fazer modelagens acopladas de fluxo e geomecânica em que cada tipo de rocha é representado individualmente. Visando essas análises integradas, mas sem aumento do custo computacional, utiliza-se o pseudoacoplamento, o que permite que esses modelos sejam usados de forma rotineira pelos engenheiros de reservatórios. Esse tipo de acoplamento atualiza a porosidade e a permeabilidade com base em tabelas que relacionam poropressão com multiplicadores de porosidade e permeabilidade. Visando uma boa representação do comportamento da rocha-reservatório, as tabelas de pseudoacoplamento são elaboradas com base em ensaios mecânicos laboratoriais realizados com amostras do próprio campo, representativas de cada fácies. São realizadas análises comparativas utilizando modelos homogêneos e heterogêneos, variando o tipo de representação da geomecânica, que pode ser através da compressibilidade ou do pseudoacoplamento. Conhecidos os efeitos geomecânicos da compactação, a etapa final desta metodologia consiste no estudo de um modelo que visa atenuá-los. / [en] Carbonate reservoirs are responsible for over 50 per cent of world hydrocarbon production. In Brazil, they started to gain more importance after the Pre-Salt discovery, in 2006. The main method to predict and manage reservoirs is numerical simulation in which, traditionally, the only geomechanical parameter is the rock compressibility. Usually it is adopted one single value for the whole model, which is kept constant. During exploitation, though, the reservoir-rock deforms, causing porosity and permeability reduction. While the first effect is not well predicted by rock compressibility, the second is simply kept constant. Besides that, each facies has its own stress-strain behavior. That is why it is so important to model the reservoir flow coupled to geomechanics representing each rock type in a single layer. With the aim of obtaining these integrated analyses, but without additional computational cost, the pseudo-coupling is used, which lets such models to be ran on day-by-day basis by reservoir engineers. This kind of coupling updates both porosity and permeability based on tables that correlate porepressure and porosity and permeability multipliers. In order to have the mechanical behavior of the reservoir-rock well represented, the pseudo-coupling tables are elaborated based on laboratory mechanical tests with samples from the same field to be modeled. In this way, each facies represented on the model has its own table that takes to reservoir simulation the geomechanical effects through porosity and permeability variation. Comparative analyses are done using homogeneous and heterogeneous models, varying the type of geomechanical representation, through rock compressibility or pseudo-coupling. Once known the compaction geomechanical effects, it is simulated a model that tries to attenuate them.
690

Caracterização da matéria-prima (Grupo Itapucumí) e sua queimabilidade para a produção de cimento Portland na industria nacional del cemento (Paraguai) / Characterization of the raw material (Itapucumí Group) and its burnability for the production of Portland cement in the Industria Nacional del Cemento (Paraguay).

Arias Cáceres, Alberto Eulogio 10 April 2018 (has links)
O presente trabalho consiste na detalhada caracterização geológica da Mina de Vallemí no Paraguai, utilizada para fabricação de cimento Portland pela Industria Nacional de Cemento (INC), seguida da caracterização das matérias-primas, por petrografia e análises químicas e mineralógicas, e posteriores testes de queimabilidade de seis farinhas experimentais, elaboradas com misturas das matérias-primas disponíveis. As farinhas foram sinterizadas e avaliadas qualitativamente, por microscopia do clínquer, e quantificadas por difração de raios-X (DRX) e método de Rietveld. A geologia da mina consiste em metapelitos, por vezes em alternâncias rítmicas, com metacalcários (metaritmito) da Formação Vallemí, basal, sobrepostos por metacalcários puros, com intercalações de metadolomito, da Formação Camba Jhopo, ambas do Grupo Itapucumí (Ediacarano), dispostas em dobra isoclinal com flanco invertido (Faixa de Dobramentos Vallemí). Dada à diversidade litológica e complexidade tectônica, o estudo requereu mapeamento geológico detalhado (escala 1:2000), com coleta de amostras e análise química concomitante, no laboratório de qualidade da indústria, e atualização da topografia e modelagem 3D. Foram individualizados nove litotipos: 1) Litotipo Misto (Itá jopara); 2) Litotipo Ritmito Verde (Itá hovy?); 3) Litotipo Ritmito Vermelho (Itá pytã); 4) Litotipo Calcário Cinza (Itá hungy); 5) Litotipo Calcrete (Itá manduvi sa\'yju); 6) Litotipo Dolomito (Itá pytãngy); 7) Litotipo Arenito Vermelho (Itá atã pytã); 8) Litotipo Lamprofiro (Itá h?); 9) Litotipo Vulcânica Básica (Itá kui sa\'yju), sendo os cincos primeiros apropriados para fabricação de cimento. O Litotipo Dolomito é apropriado se usado em misturas e os demais são materiais estéreis. Foram realizadas seis diferentes misturas de litotipos, além da normalmente empregada na indústria, utilizada como referência, com avaliação do índice de queimabilidade (IQ) nos laboratórios da Associação Brasileira de Cimento Portland (ABCP). As farinhas D1, D3 e D4 foram classificados como fácil de queimar, e as demais, D2, D5b e D6b, com queimabilidade normal. Pode-se dizer que todas apresentam índices de queimabilidade compatíveis com os padrões exigidos para a produção de cimento Portland, destacando que a melhor mistura foi obtida com a farinha D4 (composta por Litotipo Ritmito Vermelho 83,07%, Litotipo Ritmito Verde 14,45% e mineral de ferro 1,48%), e a de menor desempenho a D5b (composta por Litotipo Calcrete 50,17%, Litotipo Misto 48,32% e mineral de ferro 1,52%), o que foi possível também corroborar na quantificação das fases do clínquer. / The present work deals with a detailed geological characterization of the Vallemí Mine in Paraguay, explored to manufacture of Portland cement by the National Cement Industry (INC), followed by the characterization of the raw materials, by petrography, chemical and mineralogical analyzes, and subsequent burnability tests of six experimental raw mixtures, prepared with mixtures of available raw materials. The flours were sintered and evaluated qualitatively by clinker microscopy and quantified by X-ray diffraction (XRD) and Rietveld method. The geology of the mine includes metapelites, sometimes in rhythmic alternations, with metalimestone of the Vallemí Formation, basal, overlapped by pure metalimestone, with intercalation of metadolomite, of the Camba Jhopo Formation, both of the Itapucumí Group (Ediacaran), arranged in fold isoclinal with inverted flank (Vallemí Folding Belt). Due to the lithological diversity and tectonic complexity, the study required detailed geological mapping (scale 1: 2000), with sample collection and concomitant chemical analysis, in the industrial quality laboratory, and updating the topography and 3D modeling. Nine lithotypes were individualized: 1) Litotipo Misto (Itá jopara); 2) Litotipo Ritmito Verde (Itá hovy?); 3) Litotipo Ritmito Vermelho (Itá pytã); 4) Litotipo Calcário Cinza (Itá hungy); 5) Litotipo Calcrete (Itá manduvi sa\'yju); 6) Litotipo Dolomito (Itá pytãngy); 7) Litotipo Arenito Vermelho (Itá atã pytã); 8) Litotipo Lamprofiro (Itá h?); 9) Litotipo Vulcânica Básica (Itá kui sa\'yju), the first five suitable for manufacturing cement. Litotipo Dolomito is applicable if used in mixtures. The others lithotype are sterile materials. Six different mixtures of lithotypes were carried out, besides the one normally used in industry, used as reference, with evaluation of the burnability index (IQ) in the laboratories of the Assocciação Brasileira de Cimento Portland (ABCP). Flours D1, D3 and D4 were classified as easy to burn, and the others, D2, D5b and D6b, with normal burning. It is possible to say that all of them have a comparable burnability index compatible with the standards required for Portland cement production, the best mixture was obtained with the raw mixture D4 (composed by Litotipo Ritmito Vermelho 83,07%, Litotipo Ritmito Verde 14,45% and iron ore 1,48%) and the D5b (composed by Litotipo Calcrete 50,17%, Litotipo Misto 48,32% and iron ore 1,52%) appear as the worst, which were corroborated in the quantification of clinker phases.

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