Made available in DSpace on 2014-12-17T14:08:47Z (GMT). No. of bitstreams: 1 JeanCSG_DISSERT.pdf: 2590836 bytes, checksum: a8999e4e7cb4dfe6cb037286ddf5336d (MD5) Previous issue date: 2011-05-27 / Currently the uncertain system has attracted much academic community from the standpoint of scientific research and also practical applications. A series of mathematical approaches emerge in order to troubleshoot the uncertainties of real physical systems. In this context, the work presented here focuses on the application of control theory in a nonlinear dynamical system with parametric variations in order and robustness. We used as the practical application of this work, a system of tanks Quanser associates, in a configuration, whose mathematical model is represented by a second order system with input and output (SISO). The control system is performed by PID controllers, designed by various techniques, aiming to achieve robust performance and stability when subjected to parameter variations. Other controllers are designed with the intention of comparing the performance and robust stability of such systems. The results are obtained and compared from simulations in Matlab-simulink. / Atualmente os sistemas que qpresentam incertezas t?m atra?do muito a comunidade acad?mica do ponto de vista da investiga??o cient?fica e tamb?m das aplica??es pr?ticas. Uma s?rie de abordagens matem?ticas surgem com o objetivo de resolver problemas relacionados ?s incertezas de sistemas f?sicos reais. Nesse contexto, o trabalho aqui apresentado tem como foco a aplica??o da teoria de controle em um sistema din?mico n?o linear e com varia??es param?tricas visando a robustez. Utilizamos, como aplica??o pr?tica deste trabalho, um sistema de tanques associados da Quanser, em uma configura??o cujo modelo matem?tico ? representado por um sistema de segunda ordem com uma entrada e uma sa?da (SISO). O controle do sistema ? realizado por controladores PIDs, projetados por diversas t?cnicas, objetivando alcan?ar o desempenho e estabilidade robusta, quando submetido a varia??es de par?metros. Outros controladores s?o projetados com esse mesmo intuito e os resultados obtidos s?o comparados a partir de simula??es realizadas no Matlabsimulink.

Made available in DSpace on 2014-12-17T14:09:18Z (GMT). No. of bitstreams: 1 AndreLSS_TESE.pdf: 5521921 bytes, checksum: f9408bc166edc779a453c6cc730acf4f (MD5) Previous issue date: 2014-04-04 / The objective of this Doctoral Thesis was monitoring, in trimestral scale, the coastal morphology of the Northeastern coast sections of Rio Grande do Norte State, in Brazil, which is an area of Potiguar Basin influenced by the oil industry activities. The studied sections compose coastal areas with intense sedimentary erosion and high environmental sensitivity to the oil spill. In order to achieve the general objective of this study, the work has been systematized in four steps. The first one refers to the evaluation of the geomorphological data acquisition methodologies used on Digital Elevation Model (DEM) of sandy beaches. The data has been obtained from Soledade beach, located on the Northeastern coast of Rio Grande Norte. The second step has been centered on the increasing of the reference geodetic infrastructure to accomplish the geodetic survey of the studied area by implanting a station in Corta Cachorro Barrier Island and by conducting monitoring geodetic surveys to understand the beach system based on the Coastline (CL) and on DEM multitemporal analysis. The third phase has been related to the usage of the methodology developed by Santos; Amaro (2011) and Santos et al. (2012) for the surveying, processing, representation, integration and analysis of Coastlines from sandy coast, which have been obtained through geodetic techniques of positioning, morphological change analysis and sediment transport. The fourth stage represents the innovation of surveys in coastal environment by using the Terrestrial Laser Scanning (TLS), based on Light Detection and Ranging (LiDAR), to evaluate a highly eroded section on Soledade beach where the oil industry structures are located. The evaluation has been achieved through high-precision DEM and accuracy during the modeling of the coast morphology changes. The result analysis of the integrated study about the spatial and temporal interrelations of the intense coastal processes in areas of building cycles and destruction of beaches has allowed identifying the causes and consequences of the intense coastal erosion in exposed beach sections and in barrier islands / O objetivo da Tese de Doutorado foi o monitoramento da morfologia costeira em escala trimestral de trechos do Litoral Setentrional do Estado do Rio Grande do Norte, ?rea da Bacia Potiguar sob a influ?ncia das atividades petrol?feras. Trata-se de setores costeiros marcados por intensa eros?o sedimentar e de alta sensibilidade ambiental ao derramamento de ?leo. Para atingir o objetivo geral deste estudo, o trabalho foi sistematizado em quatro etapas. A primeira etapa apresenta a avalia??o das metodologias de aquisi??o de dados geomorfol?gicos utilizada na modelagem digital de eleva??o de praias arenosas a partir de dados obtidos na praia de Soledade, localizada no Litoral Setentrional do Rio Grande do Norte. A segunda etapa foi a amplia??o da infraestrutura geod?sica de refer?ncia para a realiza??o dos levantamentos geod?sicos da ?rea de estudo atrav?s da implanta??o de uma esta??o na ilha barreira de Corta Cachorro e de levantamentos geod?sicos de monitoramento para o entendimento do sistema praial com uso de an?lises multitemporal de LC e MDE. A terceira etapa consistiu na utiliza??o da metodologia geod?sica para o levantamento, processamento, representa??o, integra??o e an?lises de Linhas de Costa (LC) de litorais arenosos obtidos por t?cnicas geod?sicas de posicionamento, an?lise das altera??es morfol?gicas e transporte de sedimentos A quarta etapa foi definida pela inova??o de levantamentos em ambientes costeiros com a utiliza??o do Laser Esc?ner Terrestre (LiDAR) para avalia??o de um trecho submetido a intensa eros?o na praia de Soledade onde est?o instaladas infraestruturas da ind?stria petrol?fera, por meio de MDE de alta precis?o e acur?cia no modelamento das modifica??es na morfologia costeira. As an?lises dos resultados do estudo integrado das interrela??es espaciais e temporais dos intensos processos costeiros atuantes na ?rea ao longo de ciclos de constru??o e destrui??o das praias permitiram identificar as causas e consequ?ncias da intensa eros?o costeira em setores de praias expostas e ilhas barreiras

Submitted by Automação e Estatística (sst@bczm.ufrn.br) on 2018-04-11T21:18:24Z No. of bitstreams: 1 MarcusViniciusDantasDeAssuncao_TESE.pdf: 3924049 bytes, checksum: 2bd07814ac26aecc1ce04a7267e5a41d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-04-17T22:59:55Z (GMT) No. of bitstreams: 1 MarcusViniciusDantasDeAssuncao_TESE.pdf: 3924049 bytes, checksum: 2bd07814ac26aecc1ce04a7267e5a41d (MD5) / Made available in DSpace on 2018-04-17T22:59:55Z (GMT). No. of bitstreams: 1 MarcusViniciusDantasDeAssuncao_TESE.pdf: 3924049 bytes, checksum: 2bd07814ac26aecc1ce04a7267e5a41d (MD5) Previous issue date: 2018-02-26 / A indústria petrolífera possui uma significativa e importante parcela na matriz energética mundial com uma produção estimada de 1/3 da energia global. Com o elevado consumo mundial de petróleo, o gerenciamento dos recursos necessita ser melhor administrado a fim de reduzirem os impactos ambientais associados. Uma das principais preocupações ambientais associadas a exploração e produção dos campos de petróleo está relacionada a geração de água produzida de petróleo. A água produzida de petróleo constitui um desafio de natureza estratégica para as empresas, uma vez que gera a maior parcela dos resíduos da indústria do petróleo. Nessa perspectiva, este trabalho tem como objetivo avaliar o desempenho da sustentabilidade ambiental, a partir da geração de água produzida de petróleo, dos campos onshore das bacias petrolíferas costeiras do Brasil. Os dados foram disponibilizados pela ANP (Agência Nacional de Petróleo) em seu sítio eletrônico perfazendo um total de 156 campos pertencentes às bacias de Alagoas, Camamu, Espírito Santo, Potiguar e Sergipe. Os anos analisados foram 2014, 2015 e 2016. Os resultados foram apresentados em seis etapas: etapa I – apresentação dos resultados das estatísticas descritivas; etapa II – análise das regressões múltiplas; etapa III – aplicação da mediana; etapa IV – Análise da modelagem dinâmica (DDEA); etapa V - apresentação de uma análise gráfica bidimensional do DDEA; e, etapa VI - análise das regressões logísticas. Utilizaram-se dois testes estatísticos para validação das hipóteses: teste T e teste de Wald. Os resultados apresentaram efeito positivo das variáveis poços direcionais, poços verticais e idade, e, tendo essas duas primeiras, papel fundamental na determinação das eficiências ambientais. Os campos de petróleo produziram baixos índices de eficiência dinâmica tanto para o Grupo 1 (27,30%) quanto para o Grupo 2 (38,58%), representados por meio da representação gráfica bidimensional dinâmica e seus índices confirmados por meio da regressão logística. Os resultados autorizam dizer que há um mau gerenciamento dos recursos tecnológicos dos campos onshore das bacias costeiras brasileiras, provocando quantidades excessivas da água produzida de petróleo. / The oil industry has a significant and important share in the world energy matrix with an estimated production of 1/3 of the global energy. With the high world oil consumption, resource management needs to be better managed in order to reduce the associated environmental impacts. One of the main environmental concerns associated with the exploration and production of oil fields is related to the generation of water produced from petroleum. The water produced from the production of oil and gas is a strategic challenge for companies, as it generates the largest share of waste from the oil industry. In this perspective, this work aims to evaluate the performance of environmental sustainability, based on the generation of oil produced water, from the onshore fields of the coastal oil basins of Brazil. The data were made available by the ANP (National Agency of Petroleum) in its electronic site making a total of 156 oilfields belonging to the basins of Alagoas, Camamu, Espírito Santo, Potiguar and Sergipe. The years analyzed were 2014, 2015 and 2016. The results were presented in six stages: stage I - presentation of the results of the descriptive statistics; stage II - analysis of multiple regressions; stage III - application of the median; stage IV - Dynamic modeling analysis (DDEA); Stage V - presentation of a two-dimensional graphical analysis of DDEA; and stage VI - analysis of logistic regressions. Two statistical tests were used to validate the hypotheses: T-test and Wald test. The expected results will help the managers in the managerial decision making from the model proposed for the petroleum sector. The results had a positive effect on the variables directional wells, vertical wells and age, and, with these two first ones, a fundamental role in the determination of the environmental efficiencies. The oilfields produced low rates of dynamic efficiency for both Group 1 (27.30%) and Group 2 (38.58%), represented by dynamic two-dimensional graphical representation and their indices confirmed by logistic regression. The results allow to say that there is a poor management of the technological resources of the onshore fields of the Brazilian coastal basins, causing excessive amounts of the oil produced water.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-04T22:04:54Z No. of bitstreams: 1 ErnestoVargasBautista_TESE.pdf: 4056194 bytes, checksum: 4254be419758b8c4d81ac80a522fc9b3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-07T21:31:17Z (GMT) No. of bitstreams: 1 ErnestoVargasBautista_TESE.pdf: 4056194 bytes, checksum: 4254be419758b8c4d81ac80a522fc9b3 (MD5) / Made available in DSpace on 2016-01-07T21:31:17Z (GMT). No. of bitstreams: 1 ErnestoVargasBautista_TESE.pdf: 4056194 bytes, checksum: 4254be419758b8c4d81ac80a522fc9b3 (MD5) Previous issue date: 2014-11-13 / A distribui??o e mobiliza??o ou n?o dos fluidos num meio poroso dependem das for?as capilar, viscosa e gravitacional. Em campo, os processos de recupera??o avan?ada de ?leo envolvem a import?ncia e a altera??o destas for?as para incrementar o fator de recupera??o de ?leo. No caso do processo de drenagem gravitacional assistida por g?s (GAGD ? GasAssisted Gravity Drainage) ? importante entender a f?sica e mecanismos que mobilizam o ?leo atrav?s da intera??o destas for?as. Para isso, v?rios autores desenvolveram modelos f?sicos em escala de laborat?rio e testemunhos do GAGD para estudar o desempenho destas for?as atrav?s de grupos adimensionais. Estes modelos apresentaram resultados conclusivos. Por?m, modelos de simula??o num?rica foram pouco usados. O objetivo deste trabalho ? estudar a inter-rela??o das for?as capilar, viscosa e gravitacional no GAGD e suas influ?ncias no fator de recupera??o de ?leo atrav?s de um modelo de simula??o num?rica 2D. Para analisar cada uma dessas for?as, foram usados os grupos adimensionais reportados na literatura, N?mero Capilar (Nc), N?mero de Bond (Nb) e N?mero Gravitacional (Ng). Uma compara??o dos resultados obtidos neste trabalho tamb?m foi realizada com os resultados da literatura. Os resultados mostraram que antes da erup??o do g?s injetado, quanto menor ? o Nc e Nb, maior ? a recupera??o de ?leo, e ap?s da erup??o, quanto menor ? o Ng, maior ? a recupera??o de ?leo no GAGD. Uma boa rela??o foi encontrada entre os resultados deste trabalho e os resultados publicados na literatura / The distribution and mobilization of fluid in a porous medium depend on the capillary, gravity, and viscous forces. In oil field, the processes of enhanced oil recovery involve change and importance of these forces to increase the oil recovery factor. In the case of gas assisted gravity drainage (GAGD) process is important to understand the physical mechanisms to mobilize oil through the interaction of these forces. For this reason, several authors have developed physical models in laboratory and core floods of GAGD to study the performance of these forces through dimensionless groups. These models showed conclusive results. However, numerical simulation models have not been used for this type of study. Therefore, the objective of this work is to study the performance of capillary, viscous and gravity forces on GAGD process and its influence on the oil recovery factor through a 2D numerical simulation model. To analyze the interplay of these forces, dimensionless groups reported in the literature have been used such as Capillary Number (Nc), Bond number (Nb) and Gravity Number (Ng). This was done to determine the effectiveness of each force related to the other one. A comparison of the results obtained from the numerical simulation was also carried out with the results reported in the literature. The results showed that before breakthrough time, the lower is the injection flow rate, oil recovery is increased by capillary force, and after breakthrough time, the higher is the injection flow rate, oil recovery is increased by gravity force. A good relationship was found between the results obtained in this research with those published in the literature. The simulation results indicated that before the gas breakthrough, higher oil recoveries were obtained at lower Nc and Nb and, after the gas breakthrough, higher oil recoveries were obtained at lower Ng. The numerical models are consistent with the reported results in the literature

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-14T20:06:38Z No. of bitstreams: 1 CamilaGiseleDamascenoPeixoto_DISSERT.pdf: 4730926 bytes, checksum: d89e75f06427057e5b75359107c6228a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-18T22:06:35Z (GMT) No. of bitstreams: 1 CamilaGiseleDamascenoPeixoto_DISSERT.pdf: 4730926 bytes, checksum: d89e75f06427057e5b75359107c6228a (MD5) / Made available in DSpace on 2016-01-18T22:06:35Z (GMT). No. of bitstreams: 1 CamilaGiseleDamascenoPeixoto_DISSERT.pdf: 4730926 bytes, checksum: d89e75f06427057e5b75359107c6228a (MD5) Previous issue date: 2014-09-24 / Um dos principais problemas relacionados ? utiliza??o do ?leo diesel como combust?vel ? a presen?a de enxofre (S) que provoca polui??o no meio ambiente e corros?o nos motores. Com o intuito de minimizar as consequ?ncias decorrentes da libera??o deste poluente, a legisla??o brasileira estabeleceu limites m?ximos de teor de enxofre que os combust?veis podem apresentar. Para atender ?s exig?ncias, o ?leo diesel com concentra??o m?xima de enxofre igual a 10 mg/kg (S10) vem sendo amplamente comercializado no pa?s. Entretanto, a redu??o no teor de enxofre pode acarretar mudan?as nas propriedades f?sico-qu?micas do combust?vel, as quais s?o essenciais para o desempenho dos ve?culos. Este trabalho tem como objetivo a identifica??o das principais mudan?as nas propriedades f?sico-qu?micas do ?leo diesel e como elas est?o relacionadas ? redu??o do teor de enxofre. Foram testadas amostras de ?leo diesel dos tipos S10, S500 e S1800 de acordo com as metodologias da American Society for Testing and Materials (ASTM). As propriedades f?sico-qu?micas de massa espec?fica, ponto de fulgor, viscosidade cinem?tica e propriedades a baixa temperatura foram determinadas. Os ?leos tamb?m foram caracterizados por termogravimetria (TG) e submetidos ? destila??o f?sica (ASTM D86) e destila??o simulada por cromatografia gasosa (ASTM D2887). Os resultados da caracteriza??o f?sico-qu?mica mostraram que a redu??o do enxofre tornou os combust?veis mais leves e fluidos, permitindo uma maior aplicabilidade a ambientes com baixas temperaturas e uma maior seguran?a para o transporte e armazenamento. Atrav?s dos dados de destila??o simulada foi observado que a diminui??o do teor de enxofre provocou aumento das temperaturas de ebuli??o das fra??es iniciais e a redu??o das temperaturas de ebuli??o das fra??es m?dias e pesadas. A TG revelou um evento de perda de massa, atribu?do ? volatiliza??o ou destila??o de hidrocarbonetos leves e m?dios. A partir destes dados, o comportamento cin?tico das amostras foi estudada e verificou-se que as energias de ativa??o (Ea) pouco variaram ao longo da convers?o. v Considerando a m?dia dessas energias, o S1800 apresentou a Ea mais elevada no decorrer da convers?o e o S10 os menores valores / One of the main problems related to the use of diesel as fuel is the presence of sulfur (S) which causes environmental pollution and corrosion of engines. In order to minimize the consequences of the release of this pollutant, Brazilian law established maximum sulfur content that diesel fuel may have. To meet these requirements, diesel with a maximum sulfur concentration equal to 10 mg/kg (S10) has been widely marketed in the country. However, the reduction of sulfur can lead to changes in the physicochemical properties of the fuel, which are essential for the performance of road vehicles. This work aims to identify the main changes in the physicochemical properties of diesel fuel and how they are related to reduction of sulfur content. Samples of diesel types S10, S500 and S1800 were tested according with the methods of the American Society for Testing and Materials (ASTM). The fuels were also characterized by thermogravimetric analysis (TG) and subjected to physical distillation (ASTM D86) and simulated distillation gas chromatography (ASTM D2887). The results showed that the reduction of sulfur turned the fuel lighter and fluid, allowing a greater applicability to low temperature environments and safer for transportation and storage. Through the simulated distillation data was observed that decreasing sulfur content resulted in higher initial boiling point temperatures and the decreasing of the boiling temperature of the medium and heavy fractions. Thermogravimetric analysis showed a loss event mass attributed to volatilization or distillation of light and medium hydrocarbons. Based on these data, the kinetic behavior of the samples was investigated and it was observed that the activation energies (Ea) did not show significant changes throughout conversion. Considering the average of these energies, the S1800 had the highest Ea during the conversion and the S10 the lowest values

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-20T21:22:09Z No. of bitstreams: 1 RobivalAlvesRibeiro_TESE.pdf: 2206825 bytes, checksum: 2cb9e24716fd72830d590b545945791d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-22T20:33:51Z (GMT) No. of bitstreams: 1 RobivalAlvesRibeiro_TESE.pdf: 2206825 bytes, checksum: 2cb9e24716fd72830d590b545945791d (MD5) / Made available in DSpace on 2016-01-22T20:33:51Z (GMT). No. of bitstreams: 1 RobivalAlvesRibeiro_TESE.pdf: 2206825 bytes, checksum: 2cb9e24716fd72830d590b545945791d (MD5) Previous issue date: 2014-12-17 / Esta pesquisa tem como objetivo verificar se ? poss?vel construir padr?es espaciais em reservat?rios de petr?leo, usando expoentes de DFA (Detrended Fluctuation Analysis) dos diferentes perfis geol?gicos como: s?nico, densidade, porosidade, resistividade e raios gama. Fizeram parte da amostra 54 po?os de petr?leo do campo de Namorado, localizados na bacia de Campos, no estado do Rio de Janeiro, Brasil. Com o intuito de verificar a correla??o linear, constru?ram-se matrizes de dist?ncias entre os po?os e matrizes de diferen?as entre os DFA dos po?os, comparadas duas a duas e utilizado como m?todo estat?stico o teste de Mantel. A hip?tese nula consiste em afirmar que n?o existe correla??o linear entre as estruturas espaciais formadas pelas matrizes de dist?ncias euclidianas e das diferen?as dos expoentes de DFA dos perfis geol?gicos. Os perfis s?nicos (p=0,18) e da densidade (p=0,26) foram os que revelaram uma tend?ncia ? correla??o ou correla??o fraca. Estudo complementar, utilizando o contour plot, mostra os padr?es s?nicos e da densidade compat?veis com presen?a de correla??o espacial, corroborando os revelados pelo teste de Mantel / This research aims to set whether is possible to build spatial patterns over oil fields using DFA (Detrended Fluctuation Analysis) of the following well logs: sonic, density, porosity, resistivity and gamma ray. It was employed in the analysis a set of 54 well logs from the oil field of Campos dos Namorados, RJ, Brazil. To check for spatial correlation, it was employed the Mantel test between the matrix of geographic distance and the matrix of the difference of DFA exponents of the well logs. The null hypothesis assumes the absence of spatial structures that means no correlation between the matrix of Euclidean distance and the matrix of DFA differences. Our analysis indicate that the sonic (p=0.18) and the density (p=0.26) were the profiles that show tendency to correlation, or weak correlation. A complementary analysis using contour plot also has suggested that the sonic and the density are the most suitable with geophysical quantities for the construction of spatial structures corroborating the results of Mantel test

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T21:31:59Z No. of bitstreams: 1 JhonMoronTarifa_DISSERT.pdf: 6817189 bytes, checksum: 7bd9115ec364a2c40e8f294d8dd1dcb2 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-02-02T19:37:55Z (GMT) No. of bitstreams: 1 JhonMoronTarifa_DISSERT.pdf: 6817189 bytes, checksum: 7bd9115ec364a2c40e8f294d8dd1dcb2 (MD5) / Made available in DSpace on 2016-02-02T19:37:55Z (GMT). No. of bitstreams: 1 JhonMoronTarifa_DISSERT.pdf: 6817189 bytes, checksum: 7bd9115ec364a2c40e8f294d8dd1dcb2 (MD5) Previous issue date: 2014-12-15 / A combust?o in situ (CIS) ? o m?todo de recupera??o t?rmico mais antigo. Este m?todo consiste na queima parcial do ?leo in situ, cujo objetivo ? gerar uma frente de combust?o que ajude no movimento do ?leo. Essa frente de combust?o aquece as zonas pr?ximas, logrando a redu??o da viscosidade do ?leo e permitindo o seu deslocamento at? o po?o produtor. Apesar de parecer um processo f?cil, a combust?o in situ engloba uma s?rie de mecanismos complexos que mesmo na atualidade a torna dif?cil de representar atrav?s de modelos anal?ticos, f?sicos e de simula??o num?rica. O objetivo do trabalho ? analisar e determinar os par?metros que t?m influ?ncia no processo, destacando a cin?tica (energia de ativa??o, coeficiente de Arrhenius e porcentagem de craqueamento para a produ??o de coque durante o processo) de tr?s diferentes modelos de rea??es qu?micas e da vaz?o de inje??o do ar. Para verificar a aplicabilidade do processo no Brasil foi realizado um estudo de simula??o em reservat?rios de ?leo pesado com caracter?sticas do Nordeste Brasileiro. As simula??es foram realizadas utilizando o m?dulo ?STARS? da ?Computer Modelling Group?, com o objetivo de realizar estudos de m?todos de recupera??o avan?ada de ?leo. Dentre todos os par?metros analisados, a energia de ativa??o-fator pr?-exponencial apresentou a maior influ?ncia, ou seja, quanto menor o valor da energia de ativa??o-fator pr?-exponencial maior a fra??o de ?leo recuperada. A porcentagem de craqueamento mostrou uma forte influ?ncia no processo, devido a que enquanto menor for a quantidade de coque formado maior ? volume de ?leo recuperado. / In situ Combustion (CIS) is the oldest thermal method of oil recovery. This method consists of partial combustion of in situ oil, its goal is to generate a combustion front that helps to move the oil. This combustion front will heat the surrounding areas, achieving a reduction in oil viscosity and allowing its displacement into the production well. It may seem a simple process, however in situ combustion involves a series of complex mechanisms that difficult until today its representation through analytical models, physical models and numerical simulation. The aim of this investigation is to analyze and determine the parameters that influence the process, highlighting the kinetics of the process (activation energy, Arrhenius coefficient and percentage of cracking for the production of coke) three different models of chemical reactions and the air injection rate. To verify the applicability of the process in Brazil a simulation study was conducted in heavy oil reservoirs with characteristics of the Brazilian Northeast. The simulations were performed using the "STARS" module from the "Computer Modelling Group", which objective is to study methods of enhanced oil recovery. Among all the analyzed parameters, the activation energy-pre-exponential factor showed the greatest influence, that is, the lower the value of the activation energy-preexponential factor the higher the fraction of oil recovery. The cracking percentage also showed a strong influence in the process, the smaller the amount of coke formed the larger volume of oil recovery.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-05T23:04:43Z No. of bitstreams: 1 JacquelineFerreiraSantosMarques_DISSERT.pdf: 3556359 bytes, checksum: 513ccd80d1faa0aa4ab0703236b85dc4 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-02-16T22:34:40Z (GMT) No. of bitstreams: 1 JacquelineFerreiraSantosMarques_DISSERT.pdf: 3556359 bytes, checksum: 513ccd80d1faa0aa4ab0703236b85dc4 (MD5) / Made available in DSpace on 2016-02-16T22:34:40Z (GMT). No. of bitstreams: 1 JacquelineFerreiraSantosMarques_DISSERT.pdf: 3556359 bytes, checksum: 513ccd80d1faa0aa4ab0703236b85dc4 (MD5) Previous issue date: 2015-02-09 / A cimenta??o ? uma das opera??es mais importantes executadas entre as fases de perfura??o de um po?o. Quando essa cimenta??o n?o ? bem realizada, h? o risco de ocorrer falhas e fraturas, tanto na forma??o quanto no pr?prio cimento. Quando os reservat?rios possuem uma baixa profundidade, eles tendem a fraturar mais facilmente, devido ao seu baixo gradiente de fratura, por isso, a densidade da pasta de cimento ? de suma import?ncia para equil?brio das press?es, evitando problemas de fraturas. ? ela que vai garantir a estabilidade das press?es atuantes entre o po?o e a forma??o. Tendo em vista que s?o necess?rias pastas mais leves para promover o isolamento, sem que haja esse faturamento, ? necess?rio formular sistemas cimentantes que reduzam a press?o hidrost?tica da coluna de cimento. Para isso, s?o adicionados, ?s pastas, materiais com fun??es de reduzir a densidade. Portanto, este trabalho teve como objetivo otimizar formula??es de pastas de cimento de baixa densidade, contendo bentonita para aplica??o em po?os rasos e com baixo gradiente de fratura, como tamb?m comparar a efici?ncia do aditivo estendedor bentonita adicionado a estas pastas, atrav?s da varia??o das densidades e concentra??es e observa??o do comportamento das propriedades reol?gicas, estabilidade e resist?ncia ? compress?o. As pastas foram formuladas com os seguintes valores de densidades: 12,0 lb/gal; 12,5 lb/gal; 13,0 lb/gal e 13,5 lb/gal, com diferentes concentra??es de bentonita (1,0; 2,0; 3,0 e 4,0 %) para cada composi??o. Os resultados obtidos atrav?s dos testes reol?gicos mostraram que o incremento da concentra??o de bentonita proporcionou o aumento das part?culas dispersas no meio, provocando o aumento dos par?metros reol?gicos para todas as densidades. Nos testes de estabilidade os melhores resultados obtidos foram para densidades mais elevadas, se tornando mais est?veis com concentra??es a partir de 3 %, n?o apresentando rebaixamento. Nos testes de resist?ncia ? compress?o, a pasta com densidade de 13,5 lb/gal com concentra??o de 4,0% de bentonita obteve uma maior resist?ncia mec?nica, por?m, muito viscosa, o que pode ser dificultoso para o bombeamento. Atrav?s das caracteriza??es de difra??o de raios-X (DRX) da bentonita pura foi observado a presen?a das fases montmonrilonita e quartzo, caracter?sticos dessa argila. No DRX das pastas de cimento de 13,5 lb/gal foi observado que houve a presen?a de Etringita, portlandita, silicato de c?lcio e quartzo. Observou-se tamb?m que nas imagens obtidas por microscopia eletr?nica de varredura (MEV) a pasta de 13,5 lb/gal com 4 % de bentonita mostrou notoriamente a presen?a de agulhas de etringita, como tamb?m as fases de portlandita e silicato de c?lcio, produtos da hidrata??o do cimento. Por fim, pode-se considerar que as pastas que obtiveram melhores resultados, s?o as pastas com densidade de 13,5 lb/gal, com concentra??es de 2,0 % e 3,0 %, por serem mais est?veis e resistentes mecanicamente, comparadas com as demais com densidades menores. / The cementing is one of the most important operations executed between the stages of drilling a oil well. When the cementation isn?t well performed, there?s the risk of to occur failures and fractures, both in formation as in the cement itself. When the reservoirs have low depth, they tend to fracture more easily, due to his low gradient of fracture, therefore, the density of the cement slurry is of utmost importance to balance the pressures, avoiding fractures problems. It?ll ensure the stability of the pressures acting between the oil well and the formation. Having in mind that are necessary paste more lightweight to promote the insulation, without there being this billing, is necessary to formulate cementing systems to reduce the hydrostatic pressure of the cement column. Thereunto, are added to folders, materials with functions to reduce the density. Therefore, this study had as objective formulations optimize of a cement slurry of low density containing bentonite for application in shallow oil wells and with low gradient of fracture, as well as to compare the efficiency of the bentonite extender additive added to these pastes, by of variations of the density and concentrations and observing of behavior of the rheological properties, stability and resistance to compression. The pastes were formulated with the follows density values: 12,0 lb/gal; 12,5 lb/gal; 13,0 lb/gal to 13,5 lb/gal with different concentrations of bentonite (1,0; 2,0; 3,0 and 4,0 %) for each composition. The results obtained through the rheological tests showed that the increase in the bentonite concentration afforded the increase in particles dispersed in the middle, leading to an increased of rheological parameters for all densities. In the stability tests the best results were obtained at higher densities, becoming more stable with concentrations from 3 %, showing no relegation. In the compressive strength tests, the paste with a density of 13,5 lb/gal with concentration of 4,0 % of bentonite got a higher mechanical strength, but very viscous, which may hinder the pumping. Through the characterization of X-ray diffraction (XRD) of pure bentonite was observed the presence of montmonrilonita and quartz phases which are typical of clay. The XRD of the cement pastes of 13,5 lb/gal was observed that there was the presence of etringite, portlandite, calcium silicate and quartz. It was also observed that the images obtained by scanning electron microscopy (SEM) the paste of 13,5 lb/gal with 4 % bentonite showed notoriously the presence of ettringite needles, as well as the steps of portlandite and calcium silicate cement hydration products. Finally, it can be considered that the paste have worked best, are the pastes with a density of 13,5 lb/gal, with concentrations of 2,0 % and 3,0 %, because they are more stable and mechanically strong, compared with the other with lower densities.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-10T20:31:31Z No. of bitstreams: 1 AnaCarlaCostaAndrade_DISSERT.pdf: 4395616 bytes, checksum: 7bd9d9d5693c356b8df430de0f64bae2 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-17T19:21:33Z (GMT) No. of bitstreams: 1 AnaCarlaCostaAndrade_DISSERT.pdf: 4395616 bytes, checksum: 7bd9d9d5693c356b8df430de0f64bae2 (MD5) / Made available in DSpace on 2016-03-17T19:21:33Z (GMT). No. of bitstreams: 1 AnaCarlaCostaAndrade_DISSERT.pdf: 4395616 bytes, checksum: 7bd9d9d5693c356b8df430de0f64bae2 (MD5) Previous issue date: 2015-05-29 / Uma das diversas t?cnicas aplicadas aos processos de produ??o de petr?leo ? a eleva??o artificial, que utiliza equipamentos a fim de reduzir a press?o de fluxo no fundo do po?o, promovendo um diferencial de press?o, resultando em um aumento de vaz?o. A escolha do m?todo de eleva??o artificial depende de uma an?lise de diversos fatores, como custos iniciais de instala??o, manuten??o e condi??es existentes no campo produtor. O m?todo de Bombeio Centr?fugo Submerso (BCS) mostra-se bastante eficiente quando a finalidade ? produzir altas vaz?es de l?quido, tanto em ambientes terrestres como mar?timos, em condi??es adversas de temperatura e na presen?a de fluidos viscosos. Por defini??o, o BCS ? um m?todo de eleva??o artificial em que um motor el?trico de subsuperf?cie transforma a energia el?trica em mec?nica para acionar uma bomba centr?fuga de m?ltiplos est?gios sobrepostos, formada por um impelidor (rotor) e um difusor (estator). A bomba converte a energia mec?nica do motor em energia cin?tica sob a forma de velocidade, elevando o fluido ? superf?cie. O objetivo desse trabalho ? a implementa??o do m?todo de otimiza??o dos poliedros flex?veis, conhecido como M?todo Simplex Modificado (MSM), aplicado ao estudo da influ?ncia na modifica??o dos par?metros de entrada e sa?da no canal do impelidor de uma bomba centr?fuga de um sistema BCS. Na utiliza??o do m?todo de otimiza??o modificando os par?metros angulares da bomba, os dados resultantes aplicados nas simula??es permitiram a obten??o de valores otimizados do Head (altura de eleva??o), uma efici?ncia sem perdas e a pot?ncia com resultados diferenciados. / One of several techniques applied to production processes oil is the artificial lift, using equipment in order to reduce the bottom hole pressure, providing a pressure differential, resulting in a flow increase. The choice of the artificial lift method depends on a detailed analysis of the some factors, such as initial costs of installation, maintenance, and the existing conditions in the producing field. The Electrical Submersible Pumping method (ESP) appears to be quite efficient when the objective is to produce high liquid flow rates in both onshore and offshore environments, in adverse conditions of temperature and in the presence of viscous fluids. By definition, ESP is a method of artificial lift in which a subsurface electric motor transforms electrical into mechanical energy to trigger a centrifugal pump of multiple stages, composed of a rotating impeller (rotor) and a stationary diffuser (stator). The pump converts the mechanical energy of the engine into kinetic energy in the form of velocity, which pushes the fluid to the surface. The objective of this work is to implement the optimization method of the flexible polyhedron, known as Modified Simplex Method (MSM) applied to the study of the influence of the modification of the input and output parameters of the centrifugal pump impeller in the channel of a system ESP. In the use of the optimization method by changing the angular parameters of the pump, the resultant data applied to the simulations allowed to obtain optimized values of the Head (lift height), lossless efficiency and the power with differentiated results.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-30T19:21:48Z No. of bitstreams: 1 RosineyAraujoMartins_TESE.pdf: 7437829 bytes, checksum: d70e2a5bdc24f23fa0e528ff3972109f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-30T23:50:23Z (GMT) No. of bitstreams: 1 RosineyAraujoMartins_TESE.pdf: 7437829 bytes, checksum: d70e2a5bdc24f23fa0e528ff3972109f (MD5) / Made available in DSpace on 2016-03-30T23:50:23Z (GMT). No. of bitstreams: 1 RosineyAraujoMartins_TESE.pdf: 7437829 bytes, checksum: d70e2a5bdc24f23fa0e528ff3972109f (MD5) Previous issue date: 2014-07-01 / A distribui??o das altera??es diagen?ticas em reservat?rio silicicl?stico do Cenomaniano Superior da Bacia Potiguar sofreu influ?ncia do arcabou?o estratigr?fico e do sistema deposicional. Se??es s?smicas e perfis geof?sicos de dois po?os perfurados na por??o SW da citada bacia registram superf?cies estratigr?ficas regionais representativas de inunda??es m?ximas relacionadas a evento transgressivo. Na an?lise sequencial de oitenta metros de testemunhos (~450m de profundidade) foram reconhecidas nove f?cies deposicionais cujo padr?o de empilhamento granodecrescente ascendente limita ciclos com base conglomer?tica erosiva (lag) sobreposta por intercala??es de arenitos m?dios a muito finos com estratifica??es cruzadas (acanalada, planar e de baixo ?ngulo) e horizontais (plano-paralela, wave e flaser). O topo dos ciclos ? marcado pela deposi??o de pelitos e desenvolvimento de paleossolos e laguna. A correla??o de f?cies geneticamente relacionadas revela associa??es de preenchimento de canal, crevasse e plan?cie de inunda??o, depositadas em trato de sistema transgressivo. Descri??es detalhadas de setenta e nove l?minas delgadas auxiliadas por an?lises de MEV-EBSD/EDS, DRX e is?topos est?veis em arenitos revelaram composi??o arcosiana e arranjos texturais complexos com abundantes franjas de esmectita cobrindo continuamente constituintes prim?rios, cut?culas mecanicamente infiltradas e poros m?ldicos e intragranulares. Crescimentos epitaxiais de K-feldspato cobrem continua ou descontinuamente gr?os de microcl?nio e ortocl?sio antes de qualquer outra fase. Abundante pseudomatriz da compacta??o de intraclastos lamosos, concentrados ao longo de planos de estratifica??o, localmente substitu?da por calcita macrocristalina e pirita microcristalina e framboidal. Caulinita (livrinhos e vermicular), esmectita microcristalina, minerais de tit?nio microcristalinos e pirita substituem constituintes prim?rios. Porosidade intergranular predomina sobre a m?ldica, intragranular e de contra??o. Os poros s?o mal conectados devido ? presen?a intergranular de esmectita, crescimentos de K-feldspato, argilas infiltradas e pseudomatriz. Os arenitos foram sujeitos a condi??es eodiagen?ticas pr?ximas ? superf?cie e mesodiagen?ticas de soterramento raso. As altera??es diagen?tica reduziram a porosidade e permeabilidade deposicionais principalmente pela precipita??o de franjas de esmectita, compacta??o de intraclastos lamosos ? pseudomatriz e cimenta??o por calcita poiquilot?pica, caracterizando diferentes petrof?cies de reservat?rio. Esses produtos diagen?ticos atuaram como barreiras e desvios ao fluxo de fluido reduzindo qualidade do reservat?rio. / The distribution of diagenetic alterations in Late Cenomanian siliciclastic reservoirs from Potiguar Basin was influenced by the stratigraphic framework and the depositional system. Seismic sections and geophysical logs of two wells drilled in the SW portion of the mentioned basin above register regional stratigraphic surfaces representing maximum floods related to a transgressive event. The sequential analysis of 80 m of drill core (~450 m deep) recognized nine depositional facies with an upwards granodecrescent standard piling that limits cycles with an erosional conglomeratic base (lag) overlain by intercalations of medium to very fine sandstones showing cross bedding (channel, planar and low angled) and horizontal bedding (plane-parallel , wave and flaser). The top of the cycles is marked by the deposition of pelites and the development of paleosoils and lagoons. The correlation of genetically related facies reveals associations of channel fillings, crevasse, and flood plains deposited in a transgressive system. Detailed descriptions of seventy nine thin sections aided by MEV-EBSD/EDS, DRX and stable isotope analyses in sandstones revealed an arcosian composition and complex textural arrays with abundant smectite fringes continuously covering primary components, mechanically infiltrated cuticles and moldic and intragrain pores. K-feldspar epitaxial overgrowth covers microcline and orthoclase grains before any other phase. Abundant pseudomatrix due to the compactation of mud intraclasts concentrate along the stratification planes, locally replaced by macrocristalline calcite and microcrystalline and framboidal pyrite. Kaolinite (booklets and vermicular), microcrystalline smectite, microcrystalline titanium minerals and pyrite replace the primary components. The intergrain porosity prevails over the moldic, intragrain and contraction porosities. The pores are poorly connected due to the presence of intergranular smectite, k-feldspar overgrowth, infiltrated mud and pseudomatrix. The sandstones were subjected to eodiagenetic conditions next to the surface and shallow burial mesodiagenetic conditions. The diagenetic alterations reduced the porosity and the permeability mainly due to the precipitation of smectite fringes, compactation of mud intraclasts onto the pseudomatrix and cementing by poikilotopic calcite characterizing different reservoir petrofacies. These diagenetic products acted as barriers and detours to the flow of fluids thus reducing the quality of the reservoir.