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.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-10T19:20:11Z No. of bitstreams: 1 VanessaLimeiraAzevedoGomes_TESE.pdf: 3568027 bytes, checksum: 5b81da1eba84c90799bbf4cc69a3c6c1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-13T20:36:35Z (GMT) No. of bitstreams: 1 VanessaLimeiraAzevedoGomes_TESE.pdf: 3568027 bytes, checksum: 5b81da1eba84c90799bbf4cc69a3c6c1 (MD5) / Made available in DSpace on 2016-06-13T20:36:35Z (GMT). No. of bitstreams: 1 VanessaLimeiraAzevedoGomes_TESE.pdf: 3568027 bytes, checksum: 5b81da1eba84c90799bbf4cc69a3c6c1 (MD5) Previous issue date: 2015-11-20 / Ag?ncia Nacional do Petr?leo - ANP / A inje??o de ?gua em reservat?rios de petr?leo ? uma t?cnica de recupera??o amplamente utilizada para a recupera??o de ?leo. No entanto, a ?gua injetada cont?m part?culas suspensas que podem ser retidas, causando dano ? forma??o e perda de injetividade. Nesses casos, ? necess?rio estimular a forma??o danificada com o intuito de restaurar a injetividade dos po?os injetores. A perda de injetividade causa um grande impacto negativo ? economia de produ??o de petr?leo e, por isso, prever a injetividade ? importante para o gerenciamento de projetos de inje??o de ?gua. Modelos matem?ticos para perda de injetividade permitem estudar o efeito da qualidade da ?gua injetada bem como das caracter?sticas do po?o e da forma??o. Dessa forma, foi desenvolvido um modelo matem?tico da perda de injetividade para po?os injetores canhoneados. A novidade cient?fica deste trabalho refere-se ? modelagem e previs?o da perda de injetividade em po?os canhoneados injetores, considerando a filtra??o profunda e forma??o do reboco externo em canhoneados esferoidais. A modelagem cl?ssica para a filtra??o profunda foi reescrita em coordenadas esferoidais. A solu??o para a concentra??o de part?culas em suspens?o foi obtida analiticamente e a concentra??o de part?culas retidas, que causam dano ? forma??o, foi resolvida numericamente. Considerando uma vaz?o injetada constante e utilizando a lei de Darcy modificada, estimamos a imped?ncia, definida como sendo o inverso da injetividade normalizada pelo inverso da injetividade inicial. Finalmente, foram realizados testes de injetividade cl?ssicos para fluxo linear, em amostras de Arenito Berea, e tamb?m em amostras "canhoneadas". Os par?metros do modelo, coeficientes de filtra??o e de dano ? forma??o, obtidos a partir do tratamento dos dados, foram utilizados para a verifica??o da modelagem proposta. As simula??es mostraram um bom ajuste aos dados experimentais, sendo observado que a raz?o entre o tamanho das part?culas e dos poros tem grande influ?ncia no comportamento da perda de injetividade. / Water injection in oil reservoirs is a recovery technique widely used for oil recovery. However, the injected water contains suspended particles that can be trapped, causing formation damage and injectivity decline. In such cases, it is necessary to stimulate the damaged formation looking forward to restore the injectivity of the injection wells. Injectivity decline causes a major negative impact to the economy of oil production, which is why, it is important to foresee the injectivity behavior for a good waterflooding management project. Mathematical models for injectivity losses allow studying the effect of the injected water quality, also the well and formation characteristics. Therefore, a mathematical model of injectivity losses for perforated injection wells was developed. The scientific novelty of this work relates to the modeling and prediction of injectivity decline in perforated injection wells, considering deep filtration and the formation of external cake in spheroidal perforations. The classic modeling for deep filtration was rewritten using spheroidal coordinates. The solution to the concentration of suspended particles was obtained analytically and the concentration of the retained particles, which cause formation damage, was solved numerically. The acquisition of the solution to impedance assumed a constant injection rate and the modified Darcy?s Law, defined as being the inverse of the normalized injectivity by the inverse of the initial injectivity. Finally, classic linear flow injectivity tests were performed within Berea sandstone samples, and within perforated samples. The parameters of the model, filtration and formation damage coefficients, obtained from the data, were used to verify the proposed modeling. The simulations showed a good fit to the experimental data, it was observed that the ratio between the particle size and pore has a large influence on the behavior of injectivity decline.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-23T21:42:48Z No. of bitstreams: 1 TiagoCavalcantiDaRocha_DISSERT.pdf: 2006470 bytes, checksum: 040fe0cabeb92d020f46f16a7d13eca9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-28T21:30:50Z (GMT) No. of bitstreams: 1 TiagoCavalcantiDaRocha_DISSERT.pdf: 2006470 bytes, checksum: 040fe0cabeb92d020f46f16a7d13eca9 (MD5) / Made available in DSpace on 2016-06-28T21:30:50Z (GMT). No. of bitstreams: 1 TiagoCavalcantiDaRocha_DISSERT.pdf: 2006470 bytes, checksum: 040fe0cabeb92d020f46f16a7d13eca9 (MD5) Previous issue date: 2016-02-01 / Na ?rea do petr?leo os dados s?smicos geralmente s?o irregulares e esparsamente amostrados ao longo das coordenadas espaciais em raz?o de obst?culos na coloca??o dos geofones. M?todos de Fourier s?o eficientes se os dados de entrada est?o em uma grade de amostragem regular. Entretanto, quando o m?todo de Fourier ? aplicado a um conjunto de dados amostrados irregularmente, a ortogonalidade entre as componentes de Fourier deixam de existir e a energia de uma componente de Fourier pode ?vazar? para outros componentes, fen?meno chamado de ?vazamento espectral?. O objetivo da pesquisa desta disserta??o ? estudar a representa??o espectral de dados amostrados irregularmente. Em particular, ser? apresentada a estrutura b?sica da representa??o da transformada de Fourier n?o igualmente espa?ada (NDFT - nonuniform discrete Fourier transform), estudo de suas propriedades e demonstra??o do seu potencial no processamento do sinal s?smico. Para isso, estudamos a transformada de Fourier r?pida (FFT? - fast Fourier transform) e a transformada de Fourier r?pida n?o igualmente espa?ada (NFFT - nonuniform fast Fourier transform) que calculam rapidamente a transformada de Fourier discreta (DFT - discrete Fourier transform) e a NDFT, respectivamente. Comparamos a recupera??o do sinal usando a FFT, NDFT e NFFT. Abordamos a interpola??o do tra?o s?smico usando a transformada de Fourier anti-vazamento (ALFT - antileakage Fourier transform) para superar o problema do vazamento espectral causado pela amostragem irregular. As aplica??es a dados sint?ticos e dados reais mostraram que o m?todo ALFT funciona bem em dados s?smicos de geologia complexa, sofre pouco com a amostragem espacial irregular dos dados e os efeitos de borda e ? robusto e est?vel com dados com ru?do. Entretanto, n?o ? t?o eficiente quanto o FFT e sua reconstru??o n?o ? t?o boa no caso de preenchimento irregular de grandes buracos na aquisi??o. / In the oil prospection research seismic data are usually irregular and sparsely sampled along the spatial coordinates due to obstacles in placement of geophones. Fourier methods provide a way to make the regularization of seismic data which are efficient if the input data is sampled on a regular grid. However, when these methods are applied to a set of irregularly sampled data, the orthogonality among the Fourier components is broken and the energy of a Fourier component may "leak" to other components, a phenomenon called "spectral leakage". The objective of this research is to study the spectral representation of irregularly sampled data method. In particular, it will be presented the basic structure of representation of the NDFT (nonuniform discrete Fourier transform), study their properties and demonstrate its potential in the processing of the seismic signal. In this way we study the FFT (fast Fourier transform) and the NFFT (nonuniform fast Fourier transform) which rapidly calculate the DFT (discrete Fourier transform) and NDFT. We compare the recovery of the signal using the FFT, DFT and NFFT. We approach the interpolation of seismic trace using the ALFT (antileakage Fourier transform) to overcome the problem of spectral leakage caused by uneven sampling. Applications to synthetic and real data showed that ALFT method works well on complex geology seismic data and suffers little with irregular spatial sampling of the data and edge effects, in addition it is robust and stable with noisy data. However, it is not as efficient as the FFT and its reconstruction is not as good in the case of irregular filling with large holes in the acquisition.

Made available in DSpace on 2014-12-17T15:03:18Z (GMT). No. of bitstreams: 1 LucianoRCM.pdf: 1122130 bytes, checksum: 38b3caf9fc80157bb441aa6fd22b04ce (MD5) Previous issue date: 2007-08-24 / One of the most evident and actual concern, not only in the scientific means, but also of the public knowledge in general, is the lack problem of the potable water, that come increasing more each time, motivated mainly for the po llution of the sources, the bad use of the water and the increase of the population. In such a way, the necessity of looking for new water sources and the development of techniques to use sources minus explored is becoming even more important and urgent. T he rainwater comes being used since a long time like a supplying source, but, due the few knowledge of its characteristics, the generated preconception and the discrimination around its consumption and to the bad use of the technique of collection and stor age, it comes being little used, wasting consequently a significant parcel of this source. Trying to develop the knowing of some characteristics of the rainwater, the present work looks for to define the curve of variation of the quality of the rainwater i n three points with distinct characteristics of the city of Natal -RN, in the course of the precipitation, in some situations of time and space. For describe the curve of variation of the water s quality, some variables must be analyzed, and to be identifie d when they modify themselves in the endurance of rain, showing in which moment the purification of the water is more or less quickly. The pH, the Turbidity and the Electric Conductivity can be related with a big part of the physicist -chemistries variables found in the water and, like its analyses don't spend any material, they have easy access and measurement. The present work analyzes the curves of decline of these three variables, in three points with distinct characteristics in the city of Natal -RN, being these points: one next to the sea, another one in region with great buildings concentration and the last point in a less polluted area. For the studied region, it was during the five first millimeters of rain that occurs the biggest reduction of the exi sting impurities in the atmosphere, mainly between the first and the second millimeter, and after the five first millimeters the values of the variables stabilize. With exception of the University Campus, where initially the rainwater already has very good quality, the values of Turbidity and Electric Conductivity suffer a brusque reduction after the first millimeter of rain / Uma das preocupa??es mais evidentes e atuais, n?o s? no meio cient?fico, mas tamb?m de conhecimento do p?blico em geral, ? o problema da falta de ?gua pot?vel, que v?m aumentando cada vez mais, devido principalmente ? polui??o dos mananciais, ao mau uso da ?gua e ao aumento da popula??o. Desta forma, a necessidade de se procurar novas fontes d e ?gua e de aperfei?oar as t?cnicas de utiliza??o de fontes pouco exploradas se torna cada vez mais importante e urgente. A ?gua de chuva j? ? utilizada h? muito tempo como fonte de abastecimento, por?m, devido ao pouco conhecimento de suas caracter?sticas , ao preconceito e descrimina??o gerados em torno do seu consumo e ao mau uso da t?cnica de coleta e armazenamento, ela vem sendo subutilizada, desperdi?ando -se assim uma parcela significativa deste manancial. Buscando desenvolver o conhecimento de algumas caracter?sticas da ?gua pluvial, o presente trabalho procura definir a curva de varia??o da qualidade da ?gua da chuva em tr?s pontos com caracter?sticas distintas da cidade de Natal -RN, ao longo da precipita??o, em v?rias situa??es de tempo e de espa?o. Para que se possa descrever a curva de varia??o da qualidade da ?gua, algumas vari?veis devem ser analisadas, de forma a identificar como elas se modificam no decorrer da chuva, mostrando em qual momento a purifica??o da ?gua ? mais e menos acelerada. O pH, a Turbidez e a Condutividade El?trica podem ser relacionados com grande parte das vari?veis f?sico -qu?micas encontradas na ?gua e, como suas an?lises n?o s?o consumpt?veis, tem f?cil acesso e medi??o. O presente trabalho analisa as curvas de decaimento d estas tr?s vari?veis, em tr?s pontos com caracter?sticas distintas na cidade de Natal RN, sendo estes pontos: um pr?ximo ao mar, outro em regi?o com grande concentra??o imobili?ria e o ?ltimo ponto em ?rea menos polu?da. Para a regi?o estudada, foi durante os primeiros 5,0 mil?metros de chuva que ocorreu a grande redu??o percentual das impurezas existentes na atmosfera, principalmente entre o 1? e o 2? mil?metro, e ap?s os primeiros 5,0 mil?metros os valores das vari?veis se estabilizam. Com exce??o do Campus Universit?rio, onde inicialmente a ?gua de chuva j? apresenta qualidade muito boa, os valores de Turbidez e Condutividade El?trica sofrem redu??o brusca ap?s o 1? mil?metro de chuva

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-01-24T12:15:33Z No. of bitstreams: 1 IzabelKalineDaSilvaOliveira_TESE.pdf: 1323354 bytes, checksum: 0c2134eae1c9170e6277290fc8a4b9da (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-01-26T13:30:04Z (GMT) No. of bitstreams: 1 IzabelKalineDaSilvaOliveira_TESE.pdf: 1323354 bytes, checksum: 0c2134eae1c9170e6277290fc8a4b9da (MD5) / Made available in DSpace on 2018-01-26T13:30:04Z (GMT). No. of bitstreams: 1 IzabelKalineDaSilvaOliveira_TESE.pdf: 1323354 bytes, checksum: 0c2134eae1c9170e6277290fc8a4b9da (MD5) Previous issue date: 2017-07-28 / Ag?ncia Nacional de Petr?leo - ANP / O cloreto ? considerado um dos principais contaminantes do petr?leo, pois interfere no processo de transporte e refino e pode ser transferido para os produtos derivados finais. Durante o refino, a presen?a de cloreto pode levar a forma??o de HCl, causando s?rios problemas de corros?o. Nesse sentido, foi desenvolvida uma metodologia para determina??o de cloro em amostras de petr?leo, preparadas sob a forma de emuls?es, por espectrometria de absor??o molecular de alta resolu??o com fonte cont?nua atrav?s da mol?cula diat?mica MgCl no comprimento de onda 377,01 nm. O preparo da emuls?o foi otimizado atrav?s de um planejamento experimental Centroid-Simplex. As condi??es ?timas de preparo das emuls?es foram: 0,5mL HNO3 5% (v/v), 0,5mL de xileno e 2 mL de uma mistura dos solventes n-Propanol/ Triton X-100 na propor??o 5:1. A massa de amostra de petr?leo foi de cerca de 0,20g. Magn?sio foi usado como precursor da mol?cula de MgCl, e a concentra??o otimizada foi de 10 g L-1. Os estudos da propor??o entre Mg e Cl para favorecimento da forma??o da mol?cula mostraram que para garantir a m?xima forma??o da mol?cula de MgCl ? necess?rio utilizar uma raz?o em massa de pelo menos 500 Mg:1 Cl. Uma massa de 5 ?g de Pd foi introduzida ? cada ciclo de inje??o como modificador qu?mico, para aumentar a estabilidade t?rmica da esp?cie molecular. As temperaturas de pir?lise e vaporiza??o otimizadas foram 800 ?C e 2300 ?C, respectivamente. Para an?lise de cloro, foram utilizadas oito amostras de petr?leo da Bacia Potiguar e dois materiais de refer?ncia certificados, ?leo lubrificante aditivado (NIST 1848) e a de ?leo combust?vel (NIST 1634c), foram utilizados para a verifica??o da exatid?o do m?todo. A estrat?gia de calibra??o contra padr?es aquosos foi poss?vel, obtendo-se o LOD de 5 mg kg-1. Testes de adi??o/recupera??o foram realizados e os valores obtidos ficaram na faixa entre 92 e 117%. A metodologia proposta mostra-se simples, r?pida com preparo de amostra simplificado. / Chloride is considered an important contaminant of petroleum as it interferes with the process of transportation and refining and can be transferred to the final product derivatives. During refining, the presence of chloride may lead to the formation of HCl, causing serious corrosion problems. A methodology for the determination of chlorine in petroleum samples prepared by emulsions was developed by high resolution molecular absorption spectrometry with continuum source through the diatomic molecule MgCl, in the wavelength 377.01 nm. The preparation of the emulsion was optimized through centroid-simplex design. The conditions of preparation of the emulsions were: 0.5 mL of 5% (v / v) HNO3, 0.5 mL of xylene and 2 mL of a mixture of n-Propanol / Triton X-100 solvents in the ratio 5:1. The crude oil mass used was about 0.20 g. Magnesium was used as the precursor of the molecule, the optimized concentration was 10 g L-1. The proportional studies between Mg and Cl for the formation of molecules show that to ensure the formation of a MgCl molecule is required for a mass ratio of at least 500 Mg: 1 Cl. A mass of 5 ?g of Pd was introduced at each cycle that chemical modifier for increase the thermal stability of the molecular species. The optimized pyrolysis and vaporization temperatures were 800 ? C and 2300 ? C, respectively. For chlorine analysis, eight crude oil samples from the Potiguar Basin and two certified reference materials, lubricated oil (NIST 1848) and fuel oil (NIST 1634c) were used, to verify the accuracy of the method. The calibration strategy against aqueous standards was possible, obtaining the LOD of 5 mg kg-1. Addition / recovery tests were performed and the values obtained were between 92 and 117%, values acceptable analytically. The proposed methodology is simple, fast with simplified sample preparation.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-12T19:01:44Z No. of bitstreams: 1 JuanDeMedeirosTrindade_DISSERT.pdf: 8169895 bytes, checksum: 72cfef7f6cfc4e3b5aa05025683c319e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-16T15:05:15Z (GMT) No. of bitstreams: 1 JuanDeMedeirosTrindade_DISSERT.pdf: 8169895 bytes, checksum: 72cfef7f6cfc4e3b5aa05025683c319e (MD5) / Made available in DSpace on 2018-03-16T15:05:15Z (GMT). No. of bitstreams: 1 JuanDeMedeirosTrindade_DISSERT.pdf: 8169895 bytes, checksum: 72cfef7f6cfc4e3b5aa05025683c319e (MD5) Previous issue date: 2017-11-08 / No processamento de dados s?smicos, os dados s?o amostrados de forma irregular e muitas vezes com tra?os faltantes, em raz?o de restri??es log?sticas na distribui??o dos geofones e fontes. Isso faz com que seja necess?ria uma regulariza??o pr?via desse dado, de modo a podermos dar prosseguimento as demais t?cnicas de processamento. Esses dados irregulares podem ser manipulados no dom?nio de Fourier e em seguida interpolados para malhas regulares por uma transformada inversa de Fourier, uma vez que uma estimativa correta dos coeficientes de Fourier reconstr?i de forma eficiente o dado de entrada. Nesta disserta??o ser?o apresentados os m?todos de regulariza??o s?smica MWNI (Minimum Weighted Norm Interpolation) e Matching Pursuit nos casos mais simples, considerando a interpola??o em apenas uma dimens?o espacial. Depois ser?o mostrados os resultados num?ricos, obtidos pelas interpola??es com uma e duas dimens?es espaciais, de modo a validar os m?todos; o resultado das reconstru??es de uma se??o s?smica (um tiro do dado Marmousi) com ambos os m?todos na regulariza??o 2D (com uma dimens?o espacial); e por fim, a regulariza??o 3D (com duas dimens?es espaciais) de um dado s?smico completo do Marmousi e de um dado s?smico terrestre real. Ser?o analisadas as vantagens da regulariza??o s?smica 3D em rela??o a regulariza??o 2D e em seguida ser? feita uma compara??o entre os m?todos. Os testes num?ricos mostram que o MWNI ? mais r?pido que o Matching Pursuit, por?m esse produz resultados ligeiramente melhores. / In seismic data processing, the data are irregularly sampled and often with missing traces, due to logistic restrictions in the geophones and sources distribution. Therefore a prior regularization of this data is necessary, so that we can continue the other processing techniques. These irregular data can be manipulated in the Fourier domain and then interpolated to regular grid by an inverse Fourier transform, since a correct estimate of Fourier coefficients efficiently reconstructs the input data. In this work will be presented the MWNI (Minimum Weighted Norm Interpolation) and Matching Pursuit seismic regularization methods in the simplest cases, considering the interpolation in only one spatial dimension. Then, the numerical results obtained by interpolations with one and two spatial dimensions will be shown. Then, the results of the reconstructions of a seismic section (one shot of the Marmousi data) with both methods in the 2D regularization (with one spatial dimension) will be shown, and finally, the 3D regularization (with two spatial dimensions) of a complete seismic data of the Marmousi and a real land seismic data. We will show the advantages of 3D seismic regularization in relation to 2D regularization, and then a comparison will be made between the methods. In the numerical tests it will be shown that MWNI is faster than Matching Pursuit, but the last one produces slightly better results.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-04-02T15:10:38Z No. of bitstreams: 1 RaphaelEliedsonDaSilva_DISSERT.pdf: 2649607 bytes, checksum: bad08b3318784ee9ebd2199937f889b0 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-04-06T11:22:05Z (GMT) No. of bitstreams: 1 RaphaelEliedsonDaSilva_DISSERT.pdf: 2649607 bytes, checksum: bad08b3318784ee9ebd2199937f889b0 (MD5) / Made available in DSpace on 2018-04-06T11:22:05Z (GMT). No. of bitstreams: 1 RaphaelEliedsonDaSilva_DISSERT.pdf: 2649607 bytes, checksum: bad08b3318784ee9ebd2199937f889b0 (MD5) Previous issue date: 2017-11-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Este trabalho apresenta um modelo aperfei?oado de funcionamento bomba de fundo usado como condi??o de contorno da Equa??o de Onda Amortecida proposta por Gibbs (1963). O modelo descrito prev? as principais condi??es operacionais de uma bomba, por exemplo, bomba completa ou parcialmente preenchida por l?quido, bomba sujeita a interfer?ncia de g?s e tubing n?o ancorado. A valida??o do novo modelo, como condi??o de contorno, foi feita pela compara??o entre as cartas dinamom?tricas previstas e as cartas dinamom?tricas medidas (obtidas no Sistema Supervis?rio para Eleva??o Artificial - SISAL). Os dados de entrada para obten??o das cartas previstas foram coletados tamb?m no SISAL. Dados de um total de 14 po?os verticais da Bacia Potiguar foram coletados. Os resultados do novo modelo, como condi??o de contorno, foram coerentes com as cartas medidas. As cartas de fundo previstas foram capazes de representar as principais condi??es operacionais de uma bomba. J? as cartas de superf?cie previstas tiveram boa aproxima??o em rela??o as medidas, mas carecem de inclus?o de alguns outros fen?menos f?sicos para proporcionar a atenua??o das vibra??es de cargas. / This work presents an improved model of operation of downhole pump used as a boundary condition of the Damped Wave Equation proposed by Gibbs (1963). The described model predicts the main operating conditions of a pump, for example, complete or partial pump fillage, gas interference and unanchored tubing. The validation of the new model, as a boundary condition, was made by the comparison between predicted dynamometer cards and measured dynamometer cards (obtained in the Supervisory System for Oil Wells ? SISAL). The input data for obtaining the predicted cards were also collected in SISAL. A total of 14 vertical wells from the Potiguar Basin was collected. The results of the new model, as a boundary condition, were coherent with the measured cards. The predicted downhole cards were able to represent the main operating conditions of a pump. The predicted surface cards had a good approximation in relation to the measured cards, but the model needs some other physical phenomena to provide the attenuation of the vibrations of loads.