This dissertation presents a study on velocity modeling using ocean-bottom seismometer data (OBS) collected in 2004 and 2006 on the western Scotian slope. Gas hydrate and free gas concentrations and their distribution along the Scotian margin were derived based on the velocity results modeled with two different OBS data sets. A strong velocity increase (140-300 m/s) associated with gas hydrate was modeled for a depth of 220 m below seafloor (bsf). At the base of that high velocity zone (330 mbsf) the velocity decreases with 50-130 m/s. This depth is associated with the depth of the bottom-simulating reflector (BSR) observed in previous 2-D seismic reflection data. The gas hydrate concentrations (2-18 %) based on these velocities were calculated with an effective medium model. The velocity modeling shows that a sparser OBS spacing (~ 1 km) reveals more velocity uncertainties and smaller velocity contrasts than a denser (100 m) spaced OBS array. The results of the travel-time inverse modeling are applied in a waveform inverse modeling with OBS data in the second part of the thesis. The modeling tests were performed to obtain information on OBS instrument spacings necessary to detect low-concentration gas hydrate occurrences. The model runs show that an increase in instrument spacing leads to an increasing loss of model smoothness. However, large instrument spacings (>500 m) are beneficial for covering a wide target region with only using a few instruments, but decreasing the lateral resolution limits of the subsurface targets. In general half of the instrument spacing defines the lower boundary for the lateral width of the target structure. Waveform modeling with the 2006 OBS data has shown that low frequencies (<8 Hz) in the source spectrum are necessary to recover the background velocity of the model. The starting model derived from travel-time inversion of the 2006 data is not close enough to the true model. Thus the first-arrival waveforms do not match within half a cycle. Modeling with a starting frequency of 8 Hz and and applying data with a low signal-to-noise ratio (1.25) introduces artifacts into the final model result without updating the velocity. / Graduate

Submitted by EDWIN SANTIAGO RIOS ESCALANTE null (esre_2808@hotmail.com) on 2016-09-12T20:28:02Z No. of bitstreams: 1 template-feg-2016-VERSÃO FINAL.pdf: 3419531 bytes, checksum: 2e6eca3a01fecef269a3334812ba75d2 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-09-14T19:40:34Z (GMT) No. of bitstreams: 1 escalante_esr_me_guara.pdf: 3419531 bytes, checksum: 2e6eca3a01fecef269a3334812ba75d2 (MD5) / Made available in DSpace on 2016-09-14T19:40:34Z (GMT). No. of bitstreams: 1 escalante_esr_me_guara.pdf: 3419531 bytes, checksum: 2e6eca3a01fecef269a3334812ba75d2 (MD5) Previous issue date: 2016-07-12 / Agência Nacional de Petróleo, Gás Natural e Biocombustíveis (ANP) / Os limites superior e inferior de inflamabilidade são as concentrações máximas e mínimas de um combustível no ar, respectivamente, na qual uma chama pode se propagar, eles são considerados ferramentas chaves na predição do fogo, avaliando a possibilidade de explosão e projeto de sistemas de proteção. Existe interesse em encontrar os limites de inflamabilidade do etanol misturado com um diluente para pressões reduzidas para o futuro uso desse biocombustível em aplicações aeronáuticas tendo em conta a altitude típica de um avião comercial (<40 000 ft.). Neste trabalho foi desenvolvido experimentalmente a inflamabilidade do combustível líquido: Etanol hidratado e utilizou-se como gás diluente o nitrogênio. A bancada experimental usada, consiste de um recipiente esférico de 20 litros como câmara de aquecimento, uma fonte de ignição por faísca localizada na parte central da câmara. O líquido foi injetado com uma seringa de precisão de 1ml de volume para logo se evaporar no interior da câmara, o nitrogênio e ar foram injetados usando pressões parciais. O método para medir a inflamabilidade foi baseado na ignição elétrica e observação visual da propagação da chama conforme norma ASTM E-681. Primeiro os limites superior e inferior de inflamabilidade foram determinados para elevada temperatura (60℃) e pressão ambiente (101,325 kPa) para comparar os resultados com os dados publicados na literatura científica. Depois procedeu-se trabalhar com pressões reduzidas (80, 60, 40 e 20 kPa) para essa mesma temperatura, finalmente foram realizados testes para uma temperatura maior (110℃) para avaliar a influência da temperatura sobre os limites de inflamabilidade de misturas etanol-ar-diluente, os resultados foram plotados como função da relação e adição de nitrogênio e esses gráficos seguem a mesma tendência de trabalhos publicados na literatura científica. / The upper and lower limits of flammability are the maximum and minimum concentrations of a fuel in the air, respectively, in which the flame can spread; they are considered key tools for predicting fire, evaluating the possibility of explosion and protection system design. There is interest in finding the flammability limits of ethanol mixed with a diluent to reduced pressure for future use this biofuel in aeronautical applications having regard the typical height of a commercial aircraft (<40, 000 ft.). In this experimental work was carried flammability of the liquid fuel: Ethanol hydrate and used as a diluent gas nitrogen. The experimental apparatus consists of a 20 liters spherical vessel as heating chamber, a spark ignition source located in the central part of the chamber. The liquid was injected with a 1 ml syringe precision volume immediately evaporates in the chamber; nitrogen and air were injected using partial pressures. The method for flammability measuring was based in both visual observation electric ignition and flame propagation as defined by ASTM E-681. First, the upper and lower flammability limits were determined to a high temperature (60 ℃) and ambient pressure (101.325 kPa) to compare the results with data published in the scientific literature. After, we proceeded to work at reduced pressures (80, 60, 40 and 20 kPa) to same temperature. Finally, tests were carried out for a higher temperature (110 ℃) to evaluate the influence of temperature on the flammability limits ethanol-air-diluent mixtures, the results were plotted as a function of the relationship and adding nitrogen and these graphs follow the same trend of papers published in scientific literature.

L'utilisation des coulis d'hydrates comme Fluides Frigoporteurs Diphasiques (FFD) permet de réduire l'impact environnemental des systèmes frigorifiques car ces fluides possèdent une densité énergétique élevée. Leur application pour le stockage d'énergie thermique serait une réponse à une problématique industrielle de distribution de froid (climatisation, procédés de refroidissement). Ce projet propose d'étudier le couplage entre un dispositif de stockage et un système de distribution par coulis d'hydrates. Un réacteur bi-étagé a été conçu pour simuler le procédé. L'étude des conditions d'équilibres d'hydrates simples et mixtes dans un milieu poreux montrent la possibilité de faire varier la température d'équilibre sans dégradation de l'enthalpie de changement de phase. La cinétique de formation/dissociation des hydrates a été étudiée selon des théories de cristallisation et un modèle empirique a été obtenu. L'étude rhéologique des coulis d'hydrates simples et mixtes a mis en évidence le comportement rhéofluidifiant des coulis avec une forte tendance à l'agglomération pour le coulis d'hydrates mixtes. L'analyse de la distribution de tailles de particules a montré que le coulis a une répartition bimodale des cristaux. La caractérisation du réacteur a pu montrer l'impact de paramètres opératoires sur le temps d'induction. Un outil numérique 2D, intégrant les différents résultats empiriques obtenus, a été développé pour simuler le profil de température dans le réacteur et a été validé en première approche. / The use of hydrate slurries as two-phase secondary refrigerants (FFD) reduces the environmental impact of refrigeration systems because these fluids have a high energy density. They can be used for cold storage will be a solution at an industrial problem of cold distribution at various temperature levels (air-conditioning, cooling process or preservation temperature). In this work, we study the coupling between a storage device and a cold distribution system by hydrate slurries. For achieve this objective, a two-stage reactor has been built for simulate the process. Equilibrium conditions studies for single and mixed hydrate showed an equilibrium temperature shift in porous media without deterioration of latent heat fusion. Hydrates formation/dissociation kinetics have been studied according to crystallization classical theories and an empirical model was obtained. Rheological studies of hydrate slurries emphasized a shear-thinning behavior for both, but a high propensity for agglomeration for mixed hydrate slurry. Particle size analysis showed the slurry has bimodal crystals distribution. Experimental set-up characterization showed process parameters effect in induction time. A 2D numerical tool integrating various empirical relations was developed for modelling temperature profile in the reactor and was validated in a first approach.

Im Rahmen dieser Arbeit wurden die Komplexierungsreaktionen von dreiwertigen Lanthaniden (Ln) und Actiniden (An) mit (α-hydroxy-)carboxylathaltigen Betonzuschlagmitteln in An- und Abwesenheit von Calciumsilikathydrat-Phasen untersucht. Die erzielten Ergebnisse erlauben eine umfassende Beschreibung der Wechselwirkungen auf thermodynamischer und molekularstruktureller Ebene.

L'utilisation des coulis d'hydrates de CO2 comme fluides frigoporteurs dans le procédé de réfrigération secondaire permet de réduire l'impact environnemental des systèmes frigorifiques qui sont responsables d'importants rejets de gaz à effet de serre. Ces fluides sont également intéressants du point de vue de l'efficacité énergétique grâce à leur chaleur latente de changement de phase élevée et du point de vue de la variété des applications industrielles, la température de changement de phase pouvant être ajustée dans une large gamme. Afin d'assurer un contrôle optimal du procédé, la compréhension de la cinétique de formation des hydrates de CO2 et la maitrise de l’écoulement des coulis sont importantes.Pour l'étude cinétique, un protocole de mesure in-situ par spectroscopie Infra Rouge à Transformée de Fourier a permis de suivre en temps réel la concentration du CO2 en phase aqueuse dans un réacteur agité en conditions de formation d'hydrates. Ces mesures ont permis de quantifier la force motrice de la croissance cristalline, d’alimenter un modèle de calcul de la consommation en temps réel du CO2 lors de la formation des hydrates et d'identifier le transfert de matière à l’interface gaz/liquide comme l’étape limitante du processus. Le modèle semi-empirique de transfert de matière développé pour déterminer la vitesse de consommation du CO2 par les hydrates s’appuie sur l’étape limitante de transfert de matière à l’interface gaz/liquide dans certaines conditions. Par ailleurs, différents moyens pour améliorer la cinétique de cristallisation des hydrates de CO2 ont montré des résultats intéressants concernant l’évolution des paramètres opératoires (consommation de gaz/gaz dissous).Pour l’étude des écoulements, une caractérisation rhéologique et granulométrique des coulis d’hydrates de CO2 dans une boucle dynamique a été menée sur une gamme de fractions volumiques en solide comprise entre 7 à 14 %. Pour ce faire, les évolutions de pertes de charge en fonction du régime d'écoulement ont été mesurés et ont permis d’obtenir les paramètres du modèle rhéologique. Elles ont été complétées par des déterminations de distributions de tailles des cristaux grâce à une sonde Focused Beam Reflectance Measurement. Deux additifs antiagglomérants ont été testés et ont montré que les coulis d’hydrates présentent un comportement rhéofluidifiant. Par ailleurs, l’évolution en temps réel de la taille des cristaux d’hydrates de CO2 simple et en présence d’additifs ont été obtenues et ont confirmé l’effet d’antiagglomérant et de seuil des additifs testés sur la gamme de fractions en solide étudiée. / The use of CO2 hydrate slurries as fluids for secondary refrigeration processes allows reducing the environmental impact of refrigerating systems that are responsible of significant greenhouse gas emissions. These fluids are also energy efficient because of their phase change high latent heat and for the variety of their industrial applications, making the phase change temperature adjustable over a wide range. Therefore, for better controlling of the process, understanding the CO2 hydrates formation kinetics and the slurries flow control are important.For the kinetic study, an in-situ measurement protocol by Fourier Transform InfraRed Spectroscopy made it possible to follow in real time the CO2 concentration in the liquid phase in a stirred reactor under hydrate formation conditions. These measurements were used to quantify the crystal growth driving force, to supply a real time CO2 evolution model in the hydrate phase and to identify the mass transfer at the gas/liquid interface as the limiting step of the process. A semi-empirical model of mass transfer showed that the CO2 consumption rate by hydrates relies on the limiting step of the mass transfer at the gas/liquid under certain conditions. Moreover, various techniques to improve the CO2 hydrates crystallization kinetics showed interesting results concerning the operating parameters evolution (gas and dissolved gas consumption)For the flow study, a rheological and granulometric characterization of the CO2 hydrate slurries in a dynamic loop was conducted in the solid fraction range of 7 to 14 %. Therefore, the pressure drop measurements as a function of the flow regime were measured and the rheological model parameters were obtained, reinforced by crystals size distribution determinations thanks to a Focused Beam Reflectance Measurement probe. Two antiagglomerants additives were showed that the hydrate slurries have a rheofluidifiant behavior. Moreover, the real-time evolution of the CO2 hydrate crystals size and in the presence of additives was obtained and confirmed the effects of the antiagglomerant and threshold of the tested additives in the studied solid fraction range.

Gas hydrate formation and corrosion can cause serious safety and flow assurance problems in subsea environments. One aspect that has been given less attention is the corrosion behavior of materials in gas hydrate formation environment (GHFE). This work introduces a new technique/method for corrosion testing of materials exposed to low temperatures GHFEs. This technique allows pH monitoring, and control of test conditions like temperature. In this work, GHFE is defined as an environment that includes water, methanol and its degraded products in the presence of corrosive agents like CO2 and chloride salt at gas hydrate formation temperatures (GHFT). After 20 hrs immersion in CO2-saturated salinity environment at GHFT, as-deposited Ni-Mo alloy coating has the highest corrosion resistance of 33.28 kΩ cm2. The corrosion resistance dropped to 14.36 kΩ cm2 and 11.11 kΩ cm2 in the sweet low-salinity and sweet high-salinity test solutions respectively. The combined results of SEM/EDX showed that the Ni-Mo coating oxide layer broke down quicker in sweet high-salinity environment than sweet low-salinity environment. When carbon steel was immersed in a CO2-saturated high salinity environment at GHFT, there was slight overall change in corrosion rate (CR) as salt concentration increase from 3 wt% to 25 wt%. In degraded methanol environment, methanol showed an inhibitive effect on the corrosion of carbon steel. Higher methanol content (up to 50 vol. %) increased the corrosion rate of carbon steel at gas hydrate formation temperature, however, the corrosion rates were lower with methanol contents between 10 to 20 vol%.

Les sucres ont un rôle dans de nombreux phénomènes biologiques dont, notamment, la reconnaissance cellulaire. Par exemple, les cellules cancéreuses expriment des antigènes composés de sucres qui leurs sont propres, modifiant ainsi leur identité glycosidique par rapport à celle d’une cellule saine. Ces sucres sont reconnus spécifiquement pas des protéines que l’on nomme des lectines. Ces interactions sont faibles et non-covalentes donc difficiles à capturer. L’objectif de ce projet est de concevoir un outil permettant de capturer ces interactions ce qui en permettra une meilleure compréhension. Les stratégies déjà utilisées consistent en l’utilisation de photoréticulants. Ces molécules permettent de former un lien covalent entrer la protéine d’étude et son substrat. Bien que de nombreuses améliorations ont été effectuées depuis la création de ces outils, il reste difficile de pouvoir étudier ces interactions. Pour pallier à cela, nous avons ajouté une dimension visuelle a notre outil en incorporant un motif coumarine à notre photoréticulant qui, une fois soumise à une irradiation UV, permet de créer une liaison covalente entre notre sonde et notre protéine d’intérêt et de laisser en même temps, une trace fluorescente sur ladite protéine. Nous avons ensuite utilisé notre coumarine en présence d’une fucolectine, la BambL, en conditions dénaturantes pour laisser une trace fluorescente sur celle-ci. Notre sonde a également été utilisé pour cibler des protéines d’intérêts dans des lysats cellulaires. / Carbohydrates are involved in many biological phenomena, such as cellular recognition. As an example, cancer cells expressed there on sugared antigens and it’s modifiying their glycosidic identity compare to an healthy cell. These sugars can be recognized by proteins which are also called lectins. Interactions between the biomolecules are weak and difficult to capture. The aim of the project is to design a tool which let us able to capture and have a better understanding of theses interactions. Previous studies have shown the usefulness of the photocrosslinkers. These molecules can create a covalent bond between the protein of interest and its substrat. Although all the improvements since the creation of these tools, it is still difficult to underline sugar-protein interactions. To overcome the problem, visual parameters were incorporated to our probe with a coumarin scaffold whom, after UV irradiations, can generate a nitrene and formed a covalent bond between our probe and our targeting probe letting a fluorescent tag on the protein. The probe has been tested in presence of a fucolectine; the BambL, in denaturing conditions to check the fluorescent tag. Our probe was also tested in cell lysats conditions.

[pt] A indústria de Petróleo e Gás enfrenta desafios, particularmente a formação de hidratos em equipamentos submarinos, que podem bloquear válvulas de controle e colocar em risco a segurança e a produtividade. Os métodos atuais de remoção de hidratos são frequentemente subótimos devido aos altos custos, ao tempo de consumo e ao potencial dano ambiental. Este projeto está desenvolvendo uma ferramenta a laser de alta potência como uma solução alternativa para a remoção de hidratos, aproveitando a recente disponibilidade comercial de tais lasers. A ferramenta, projetada para ser operada por um Veículo Operado Remotamente (ROV) subaquático a profundidades de 600 m - 3500 m, é baseada em um laser de diodo azul de alta potência. Funciona transferindo calor para o hidrato, seja por absorção direta da radiação laser ou por condução de calor de partes adjacentes que absorvem a radiação. Dois protótipos foram projetados e construídos, equipados com lasers de 700 W e 1800 W, respectivamente. Esses protótipos consistem em cinco módulos: refrigeração, energia, principal, óptico e skid. Simulações e testes experimentais estão sendo conduzidos em um ambiente de laboratório para facilitar o avanço da ferramenta e garantir um design compacto e eficiente antes dos testes de campo. / [en] The Oil and Gas industry faces challenges, particularly the formation of hydrates on subsea equipment, which can block control valves and risk safety and productivity. Current hydrate removal methods are often suboptimal due to high costs, time consumption, and potential environmental damage. This project is developing a high-power laser tool as an alternative solution for hydrate removal, leveraging the recent commercial availability of such lasers. The tool, designed to be operated by an underwater Remotely Operated Vehicle (ROV) at depths of 600 m - 3500 m, is based on a high-power blue diode laser. It works by transferring heat to the hydrate either by direct absorption of the laser radiation or by heat conduction from adjacent parts absorbing the radiation. Two prototypes have been designed and constructed, equipped with 700 W and 1800 W lasers respectively. These prototypes consist of five modules: cooling, power, main, optical, and skid. Simulations and experimental tests are being conducted in a laboratory setting to facilitate the tool s advancement and ensure a compact and efficient design before field trials.

Reservoir testing and analysis are fundamental tools in understanding reservoir hydraulics and hence forecasting reservoir responses. The quality of the analysis is very dependent on the conceptual model used in investigating the responses under different flowing conditions. The use of reservoir testing in the characterization and derivation of reservoir parameters is widely established, especially in conventional oil and gas reservoirs. However, with depleting conventional reserves, the quest for unconventional reservoirs to secure the increasing demand for energy is increasing; which has triggered intensive research in the fields of reservoir characterization. Gas hydrate reservoirs, being one of the unconventional gas reservoirs with huge energy potential, is still in the juvenile stage with reservoir testing as compared to the other unconventional reservoirs. The endothermic dissociation hydrates to gas and water requires addressing multiphase flow and heat energy balance, which has made efforts to develop reservoir testing models in this field difficult. As of now, analytically quantifying the effect on hydrate dissociation on rate and pressure transient responses are till date a huge challenge. During depressurization, the heat energy stored in the reservoir is used up and due to the endothermic nature of the dissociation; heat flux begins from the confining layers. For Class 3 gas hydrates, just heat conduction would be responsible for the heat influx and further hydrate dissociation; however, the moving boundary problem could also be an issue to address in this reservoir, depending on the equilibrium pressure. To address heat flux problem, a proper definition of the inner boundary condition for temperature propagation using a Clausius-Clapeyron type hydrate equilibrium model is required. In Class 1 and 2, crossflow problems would occur and depending on the layer of production, convective heat influx from the free fluid layer and heat conduction from the cap rock of the hydrate layer would be further issues to address. All these phenomena make the derivation of a suitable reservoir testing model very complex. However, with a strong combination of heat energy and mass balance techniques, a representative diffusivity equation can be derived. Reservoir testing models have been developed and responses investigated for different boundary conditions in normally pressured Class 3 gas hydrates, over-pressured Class 3 gas hydrates (moving boundary problem) and Class 1 and 2 gas hydrates (crossflow problem). The effects of heat flux on the reservoir responses have been addressed in detail.

Reservoir testing and analysis are fundamental tools in understanding reservoir hydraulics and hence forecasting reservoir responses. The quality of the analysis is very dependent on the conceptual model used in investigating the responses under different flowing conditions. The use of reservoir testing in the characterization and derivation of reservoir parameters is widely established, especially in conventional oil and gas reservoirs. However, with depleting conventional reserves, the quest for unconventional reservoirs to secure the increasing demand for energy is increasing; which has triggered intensive research in the fields of reservoir characterization. Gas hydrate reservoirs, being one of the unconventional gas reservoirs with huge energy potential, is still in the juvenile stage with reservoir testing as compared to the other unconventional reservoirs. The endothermic dissociation hydrates to gas and water requires addressing multiphase flow and heat energy balance, which has made efforts to develop reservoir testing models in this field difficult. As of now, analytically quantifying the effect on hydrate dissociation on rate and pressure transient responses are till date a huge challenge. During depressurization, the heat energy stored in the reservoir is used up and due to the endothermic nature of the dissociation; heat flux begins from the confining layers. For Class 3 gas hydrates, just heat conduction would be responsible for the heat influx and further hydrate dissociation; however, the moving boundary problem could also be an issue to address in this reservoir, depending on the equilibrium pressure. To address heat flux problem, a proper definition of the inner boundary condition for temperature propagation using a Clausius-Clapeyron type hydrate equilibrium model is required. In Class 1 and 2, crossflow problems would occur and depending on the layer of production, convective heat influx from the free fluid layer and heat conduction from the cap rock of the hydrate layer would be further issues to address. All these phenomena make the derivation of a suitable reservoir testing model very complex. However, with a strong combination of heat energy and mass balance techniques, a representative diffusivity equation can be derived. Reservoir testing models have been developed and responses investigated for different boundary conditions in normally pressured Class 3 gas hydrates, over-pressured Class 3 gas hydrates (moving boundary problem) and Class 1 and 2 gas hydrates (crossflow problem). The effects of heat flux on the reservoir responses have been addressed in detail.