A brief review is made of the rheology of suspensions in general and cement slurries in particular. The factors influencing the flow behaviour of these systems are discussed. It is pointed out that the rheological properties of cement slurries can not be determined by theory alone from the original constituents, and experimental tests combined with empirical formulae are needed. The co-axial cylinder viscometer was used to characterise the rheological behaviour of the cement slurry used in this investigation, the slurry being made highly thixotropic by the use of additives, It is shown that no single flow model, however complex, can correctly fully describe the flow behaviour of such materials. The cement slurry used in this research programme had a structure which changed continuously with time and, when pumped through a pipe, formed a high water content slip layer on the pipe surface. An accurate theoretical solution for this type of pipe flow is lacking in the literature. A new method to predict the pressure gradient of such suspensions flowing in pipes is proposed and the technique was tested using a small pumping line and also with data extracted from the literature. The shear vane test, commonly used to measure shear strength of soils, was developed to measure gel strength of the cement slurry used in this investigation. It is shown that the gel strength measured with this technique is of considerable benefit when assessing the real material behaviour.

Cement-based materials are of importance in the construction of geothermal wells and high-temperature oil and gas wells. These materials fill the annulus between the well casing and the rock forming a protective layer, known as sealant, which is used primarily to secure and support the casing inside the well. In addition it prevents entry of unwanted fluids into the well and communication between formation fluids at different levels. These cement based sealants need to perform for many years at high temperatures and in severe chemical environments; conditions which can cause the material of the well-casing to degrade resulting in reduced strength and increased permeability. The aim of this study is to develop new materials which will have the potential properties (high strength and low permeability) for use as sealants in geothermal and deep, hot oil wells. In order to do this special cement slurries, based on the CaO−Al2O3−SiO2−H2O (CASH) hydroceramic system, have been synthesised over the temperature range 200 to 350 °C (i.e. the typical working temperature of these wells). The additives used in these cement slurries are silica flour and alumina. A detailed description of a suite of novel hydroceramic compositions over the temperature range 200 to 350 °C is given. X-ray diffraction has been used to determine the mineralogical composition and Rietveld refinement to quantify the known phases present at different temperatures. In addition the chemistry of some of the major phases present has been examined using electron probe microanalysis. Scanning electron microprobe and simulation software have been employed to study the crystal shape of these major minerals. The engineering properties of the hydroceramic materials are very important. A study of the compressive strength and permeability has been carried out over a range of temperature (200 to 350 °C). In addition permeability has been calculated using simulation software and the results compared with experimental values. Hydroceramic formulations with excellent strength and permeability measurements have been found. Some of these formulations have been tested for durability under simulated well conditions. These materials have been immersed into different brines for a certain period of time at temperatures between 200 to 300 °C. Some preliminary results regarding the changes in mineralogy in these samples are presented in this thesis. These experiments have been carried out at the Synchrotron Radiation Source (SRS) using tomographic energy-dispersive diffraction imaging (TEDII).

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Cement has been used in the world, presenting a wide versatility. However, due to its chemical nature, it is subject to several types of chemical damages, especially for agents of acidic nature. With the purpose of increase its life-time, new cement slurries have been modified with the addition of specific additives. The objective of this work is to modify cement slurries with epoxy resins, which promote higher resistance of those materials in relation to acid attacks. Three cement slurries were synthesized with epoxy resins (GY, PY-1 and PY-2) and a standard slurries, which was composed by cement and water (w/c = 0,5). The syntheses were performed according to the API recommendations. After 30 days of hydration, the samples were characterized by XDR, FTIR and thermal analysis (TG and DSC). The slurries characterization has suggested the presence of low amounts of portlandita (Ca(OH)2) in the slurry with the higher content of polymerized epoxy resin. The hydration processes of the cement slurries were studied by heat-conduction microcalorimetry. The energetic and enthalpic hydration data were all exothermic in nature. It was verified that the addition of the polymers delayed the processes of hydration of the slurries, decreasing the flow of heat released as a function of the amount of added resin. The cumulative heat release curves have shown the presence of multilinearity of the kinetic processes. The hydration microcalorimetric data were well fitted to the multistep Avrami kinetic model. A kinetic study of HCl interaction with the new slurries were performed by the batch methodology at 25, 35, 45 e 55°C. The Avrami kinetic model also appears to be the most efficient in describing the kinetic isotherms. It was observed that the kinetic constants of interaction of the acid with the slurries increased with the increase of temperature and decreased as a function of the amount of resin added in the slurries. The speed of reaction of the cement slurries with HCl was determined from the kinetic parameters obtained by the Avrami model. Speed reaction in the order of 10-3 mol.g.h-1 were found for the standard slurry and of the order of 10-5 mol.g.h-1 for the slurries with the epoxy resins. In general, the analysis of the kinetic parameters indicated that increasing the resin amount in the composition of the slurries reduced the reaction speed and increased the resistance of those slurries to the acid attack. / O cimento é um dos materiais mais utilizados no mundo, apresentando uma larga versatilidade. No entanto, devido à sua natureza química, está sujeito a vários tipos de desgastes, especialmente por agentes de natureza ácida. Com a finalidade de prolongar o tempo de vida útil desse material, buscam-se novas formulações de pastas de cimento através da adição de aditivos específicos. O objetivo deste trabalho é a modificação de pastas de cimento com resinas epóxi, as quais promovem maior resistência desses materiais frente aos ataques ácidos. Foram sintetizadas três pastas de cimento com resinas epóxi (GY, PY-1 e PY-2) e uma pasta padrão, composta de cimento e água. Para preparação utilizaram-se dois tipos de resinas epóxi, uma do tipo bisfenol-A e seu endurecedor de isoforonodiamina (GY) e outra, uma combinação do bisfenol-F e do bisfenol-A com endurecedor de poliamidoamina (PY-1 e PY-2). Após 30 dias de hidratação, as amostras foram caracterizadas por DRX, FTIR e por análise térmica (TG e DSC). A caracterização das pastas sugeriu a presença de baixas quantidades de portlandita (Ca(OH)2) nas composições com maior porcentagem de resina epóxi. Os processos de hidratação das pastas de cimento foram estudados por calorimetria isotérmica. Os dados energéticos de entalpia de hidratação foram todos de natureza exotérmica. Foi verificado que a adição do polímero retardou o processo de hidratação das pastas, reduzindo o fluxo de calor liberado em função da porcentagem de resina adicionada. As curvas de liberação do fluxo de calor mostraram a presença de vários processos cinéticos distintos. Os dados de hidratação foram bem ajustados ao modelo cinético de Avrami. O estudo cinético de interação de HCl com as pastas de cimento foi realizado pelo método de batelada nas temperaturas de 25, 35, 45 e 55°C. O modelo cinético de Avrami também foi o que mais se mostrou eficiente em descrever as isotérmicas cinéticas. Foram observados que as constantes cinéticas de interação do ácido com as pastas aumentaram com o aumento da temperatura, e diminuíram em função do aumento da quantidade de polímero adicionado nas pastas. A velocidade de reação das pastas de cimento com o HCl foi estimada a partir dos parâmetros cinéticos obtidos pelo modelo de Avrami. Foram verificados valores de velocidade de reação da ordem de 10-3 mol.g.h-1 para a pasta padrão e da ordem de 10-5 mol.g.h-1 para as pastas aditivadas. Em geral, a análise dos parâmetros cinéticos indicou que o aumento da porcentagem de resina na composição das pastas reduziu a velocidade de reação e, aumentou a resistência dessas pastas ao ataque ácido.

Made available in DSpace on 2014-12-17T14:06:59Z (GMT). No. of bitstreams: 1 FilipeSO_DISSERT.pdf: 3900853 bytes, checksum: b933d50c7767f35ccf84d3eb5899b023 (MD5) Previous issue date: 2011-05-23 / Novel cementing materials formulations containing flexible polymeric admixtures have been studied aiming at improving the mechanical behavior of oil well cement slurries submitted to steam injection. However, research activities in this sector are still under development. The steam injected directly into the well causes casing dilation, which after a reduction in temperature, tends to return to its original dimensions, resulting in crack formation and hydraulic isolation loss of the well, which will result in shortening of well life. In this scenario, the objective of the present study was to evaluate the mechanical behavior of Portland-based slurries containing SBR latex, applied in oil well cementing of wells submitted to steam injection. Were formulated slurries with densities of 1.797 g/cm3 (15.0 lb/Gal) and 1.869 g/cm3 (15.6 lb/Gal), containing admixtures with a latex concentration of 0; 66.88; 133.76; 200.64 and 267.52 L/m3 (0, 0.5, 1.0, 1.5 and 2.0 gpc). Tests including rheology, fluid loss control, thickening time, API compressive strength and splitting tensile strength, beyond steam injection simulation. Microstrutural characteristics of the slurries were also performed (XRD, TG, FTIR and SEM). The results showed that increasing the polymer concentration increased in the rheological properties and fluid loss, and a decrease in the elasticity modulus of the cement slurries. The results obtained showed that the slurries can be applied in cementing operations of oil wells submitted to steam injection. / Novas formula??es de pastas de cimento, aditivadas com materiais polim?ricos com caracter?sticas flex?veis, t?m sido estudadas para aplica??o em po?os sujeitos a inje??o de vapor. Entretanto, pesquisas neste setor ainda s?o atividades em desenvolvimento. O vapor injetado diretamente no po?o provoca a dilata??o do revestimento, o que ap?s redu??o na temperatura, tende a voltar as suas dimens?es iniciais, provocando forma??o de trincas e conseq?ente perda do isolamento hidr?ulico do po?o, que resultar? no encurtamento do tempo de sua vida ?til. Dentro deste contexto, este trabalho tem como objetivo estudar o comportamento mec?nico de sistemas de pastas de cimento Portland, aditivadas com l?tex SBR, para cimenta??o de po?os de petr?leo sujeitos a inje??o de vapor. Foram formuladas pastas com densidades de 1,797 g/cm3 (15,0 lb/Gal) e 1,869 g/cm3 (15,6 lb/Gal), aditivadas com concentra??o de 0; 66,88; 133,76; 200,64 e 267,52 L/m3 (0, 0,5, 1,0, 1,5 e 2,0 gpc) de l?tex. Foram realizados ensaios de reologia, controle de filtrado, tempo de espessamento, resist?ncia ? compress?o API e tra??o por compress?o diametral, al?m de simula??es de inje??o de vapor. Tamb?m foram realizadas caracteriza??es microestruturais das pastas de cimento (DRX, TG, FTIR e MEV). Os resultados mostraram que com o aumento da concentra??o do pol?mero ocorreram mudan?as nas propriedades reol?gicas e no volume de filtrado, al?m de uma diminui??o do m?dulo de elasticidade das pastas de cimento. A partir dos resultados obtidos verificou-se que as pastas podem ser aplicadas em opera??es de cimenta??o de po?os de petr?leo sujeitos a inje??o de vapor.

Made available in DSpace on 2014-12-17T14:07:02Z (GMT). No. of bitstreams: 1 MarcosASA_capa_ate_cap5.pdf: 2919360 bytes, checksum: 8bb04eb85df77f75f3f1de37bbecc19d (MD5) Previous issue date: 2009-04-02 / The Potiguar basin has large fields of viscous oil where the used method for recovering is based on vapor injection; this operation is carried out by injecting vapor in the oilwell directly, without the protection of a revetment through thermal insulation, what causes its dilation and, consequently, cracks in the cement placed on the annular, and lost of hydraulic insulation; this crack is occasioned by the phenomenon of retrogression of the compressive resistance due to the conversion of the hydrated calcium silicate in phases calcium-rich, caused by the high temperatures in the wells, subjected to thermal recuperation. This work has evaluated the application of composite pastes with addition of residue of biomass of ground sugar-cane bagasse as anti-retrogression mineral admixture for cementation of oil-wells subjected to thermal recuperation. The addition of the mineral residue was carried out considering a relative amount of 10, 20, 30, 40 and 59% in relation to cement mass, trying to improve the microstructure of the paste, still being developed a reference paste only with cement and a paste with addition of 40% of silica flour - renowned material in the oil industry as anti-retrogression additive. Pozzolanic activity of the ash was evaluated through XRD, TG/DTG, as the resistance to compression, and it was also determined the physical and mechanical behavior of the pastes when submitted to cure at low temperatures (22 and 38? C); besides it was evaluated the behavior of the pastes when submitted to two cycles of cure at high temperature (280?C) and pressure (7 MPa). It was verified that the ash of the sugar-cane biomass presents pozzolanic reaction and has great efficiency in decrease the permeability of the paste by filler effect, as well as that addition of ash in a relative amount of 10, 20 e 30% increases cured compressive resistance at low temperatures. It was also showed that the ash in a relative amount of 40% and 59% has very significant efficiency as anti-retrogression additive, since it prevents the decrease of compressive resistance and forms hydrated calcium silicate type xenotlita and tobermorita which have more resistance and stability in high temperatures / A bacia Potiguar tem grandes campos de ?leo viscoso, onde o m?todo de recupera??o utilizado ? a inje??o de vapor; essa opera??o ? realizada injetando-se vapor diretamente no po?o, sem a prote??o do revestimento atrav?s de isolamento t?rmico, o que provoca a dilata??o do mesmo, provocando assim falhas no cimento colocado no anular, e conseq?entemente, perda do isolamento hidr?ulico, esta falha tem origem no fen?meno de retrogress?o da resist?ncia ? compress?o devido a convers?o do silicato de c?lcio hidratado em fases ricas em c?lcio, provocada pelas elevadas temperaturas nos po?os, sujeitos ? recupera??o t?rmica. O presente trabalho avaliou a aplica??o de pastas comp?sitas com adi??o de res?duos de biomassa do baga?o da cana-de-a??car mo?das como aditivo mineral anti-retrogress?o para cimenta??o de po?os petrol?feros sujeitos a recupera??o t?rmica. A adi??o do res?duo mineral foi realizada teores de 10, 20, 30, 40 e 59% em rela??o a massa do cimento, visando melhorar a microestrutura da pasta, sendo ainda produzidas uma pasta de refer?ncia, apenas com cimento e uma pasta com adi??o de 40% de silica flour material consagrado na ind?stria de petr?leo como aditivo antiretrogress?o. Foram avaliados a atividade pozol?nica da cinza atrav?s de DRX, TG/DTG e resist?ncia ? compress?o, determinando-se tamb?m o comportamento f?sico e mec?nico das pastas submetidas a cura com baixas temperaturas (22 e 38?C), al?m da avalia??o do comportamento das pastas submetidas a dois ciclos de cura a alta temperatura (280?C) e press?o (7 MPa). Verificou-se que a cinza de biomassa da cana apresenta rea??o pozol?nica, tendo grande efici?ncia na diminui??o da permeabilidade da pasta por efeito filler, e que as adi??es de cinza em teores de 10, 20 e 30% aumentam a resist?ncia ? compress?o das pastas curadas a baixas temperaturas. Constatou-se ainda que a cinza em teores de 40% e 59% tem ?tima efici?ncia como aditivo antiretrogress?o, pois evitam a diminui??o da resist?ncia ? compress?o e formam silicato de c?lcio hidratado do tipo xenotlita e tobermorita que se apresentam mais resistentes e est?veis as altas temperaturas

Made available in DSpace on 2014-12-17T14:07:06Z (GMT). No. of bitstreams: 1 BrunoLSC_DISSERT.pdf: 3848053 bytes, checksum: 28828821b0f45645fb6dc741dc2505bf (MD5) Previous issue date: 2013-09-28 / One of the great challenges at present time related with the materials area concerns of products and processes for use in petroleum industry, more precisely related to the Pre-salt area. Progresses were reached in the last years allowing the drilling of the salt layer, with the time reduction for drilling and larger success at the end. For the oil wells companies the preponderant factor is the technology, however, in spite of the progress, a series of challenges is still susceptible to solutions and one of them refers to the slurries preparation for cementing in those areas. Inside of this context, this study had for objective to analyze the influence of the salts NaCl, KCl, CaSO4 and MgSO4 in strength and chemical structure of the hydrated products. As methodology, they were prepared and analyzed cement slurries with varied concentrations of these salts that are commonly found in the saline formations. The salts concentrations used in formulations of the slurries were of 5%, 15% and 30%. The slurries were formulated with specific weight of 15,8 lb / gal and the cement used was Class G. Strength tests were accomplished in samples cured by 24 hours and 28 days. Also were realized crystallographic characterization (XRD) and morphologic (SEM). In agreement with the presented results, it is observed that the largest resistance values are attributed to the slurries with concentration of 15%. There was reduction of the strength values of the slurries formulated with concentration of 30%. Through the characterization microstructural it was possible to note the salts influence in the main cement hydrated products / Um dos grandes desafios da atualidade relacionado com a ?rea de materiais diz respeito ? produ??o de produtos e processos para uso na ind?stria do petr?leo, mais precisamente relacionado ? ?rea do Pr?-sal. Avan?os foram alcan?ados nos ?ltimos anos permitindo a perfura??o da camada de sal, com a redu??o do tempo para perfura??o dos po?os e maior ?xito ao final da opera??o. Apesar dos avan?os, uma s?rie de desafios ainda ? pass?vel de solu??es e um deles refere-se ? prepara??o de pastas para a cimenta??o de po?os nessas zonas com camadas evapor?ticas. Dentro deste contexto, este estudo teve por objetivo analisar a influ?ncia dos sais NaCl, KCl, CaSO4 e MgSO4 no comportamento mec?nico e estrutura qu?mica dos produtos hidratados. Como metodologia, foram preparadas e analisadas pastas de cimento com concentra??es variadas destes sais que s?o comumente encontrados nas forma??es salinas do reservat?rio do Pr?-sal. As concentra??es dos sais empregadas nas formula??es das pastas foram de 5%, 15% e 30%. As pastas foram formuladas com peso espec?fico de 15,8 lb/gal e o cimento utilizado na prepara??o das pastas foi o do tipo Portland Classe G. Foram realizados ensaios de resist?ncia ? compress?o em corpos de prova curados por 24 horas e 28 dias. Tamb?m foram realizados ensaios de caracteriza??o cristalogr?fica (DRX) e morfol?gica (MEV). De acordo com os resultados apresentados, observa-se que os maiores valores de resist?ncia s?o atribu?dos ?s pastas com concentra??o de 15 % para todos os sais. Houve, tamb?m, redu??o dos valores de resist?ncia das pastas formuladas com concentra??o de 30 % para todos os sais. Atrav?s das an?lises de caracteriza??o micro estrutural foi poss?vel observar a influ?ncia dos sais nos principais produtos hidratados do cimento Portland

Made available in DSpace on 2014-12-17T14:08:39Z (GMT). No. of bitstreams: 1 Julio Cezar de oliveira Freitas_nao permite publicacao_pdf.pdf: 2629498 bytes, checksum: 933e76a7de6f0be7c8d579af7a68bb18 (MD5) Previous issue date: 2010-06-18 / The primary cementing is an important step in the oilwell drilling process, ensuring the mechanical stability of the well and the hydraulic isolation between casing and formation. For slurries to meet the requirements for application in a certain well, some care in the project should be taken into account to obtain a cement paste with the proper composition. In most cases, it is necessary to add chemicals to the cement to modify its properties, according to the operation conditions and thus obtain slurries that can move inside the jacket providing a good displacement to the interest area. New technologies of preparation and use of chemicals and modernization of technological standards in the construction industry have resulted in the development of new chemical additives for optimizing the properties of building materials. Products such as polycarboxylate superplasticizers provide improved fluidity and cohesion of the cement grains, in addition to improving the dispersion with respect to slurries without additives. This study aimed at adapting chemical additives used in civil construction to be used use in oilwell cement slurries systems, using Portland cement CPP-Special Class as the hydraulic binder. The chemical additives classified as defoamer, dispersant, fluid loss controller and retarder were characterized by infrared absorption spectroscopy, thermogravimetric analyses and technological tests set by the API (American Petroleum Institute). These additives showed satisfactory results for its application in cement slurries systems for oil wells. The silicone-based defoamer promoted the reduction of air bubbles incorporated during the stirring of the slurries. The dispersant significantly reduced the rheological parameters of the systems studied. The tests performed with the fluid loss controller and the retarder also resulted in suitable properties for application as chemical additives in cement slurries / A cimenta??o prim?ria ? uma etapa importante durante o processo de perfura??o de po?os petrol?feros, garantindo a estabilidade mec?nica do po?o e o isolamento hidr?ulico entre o tubo de revestimento e a forma??o. Para que a pasta de cimento atenda aos requisitos estabelecidos para sua aplica??o em um determinado po?o, alguns cuidados no seu projeto de execu??o devem ser levados em considera??o para a obten??o de uma pasta de cimento com composi??o adequada. Na grande maioria dos casos, ? necess?ria a adi??o de produtos qu?micos ao cimento para modificar suas propriedades, conforme as condi??es do po?o ou opera??o e, assim, obter pastas que possam se deslocar no interior do revestimento promovendo um bom deslocamento at? a zona de interesse. Novas tecnologias de prepara??o e uso de produtos qu?micos e a moderniza??o dos padr?es tecnol?gicos no setor da constru??o civil t?m resultado no desenvolvimento de novos aditivos qu?micos para a otimiza??o das propriedades dos materiais construtivos. Produtos como superplastificantes a base de policarboxilato proporcionam maior fluidez e coes?o dos gr?os de cimento, al?m de melhorar a dispers?o em rela??o ?s pastas sem aditivos. Este trabalho tem como objetivo adequar aditivos qu?micos utilizados na constru??o civil para aplica??o em sistemas de pastas de cimento de po?os petrol?feros, utilizando como aglomerante hidr?ulico o cimento Portland CPP-Classe Especial. Os aditivos qu?micos classificados como antiespumantes, dispersantes, controladores de filtrado e retardadores de pega foram caracterizados por espectroscopia de absor??o na regi?o do infravermelho, an?lise termogravim?trica e ensaios tecnol?gicos estabelecidos pelo API (American Petroleum Institute). Estes aditivos apresentaram resultados satisfat?rios para sua aplica??o em sistemas de pasta de cimento para po?os de petr?leo. O antiespumante, a base de silicone, promoveu redu??o do aprisionamento de ar durante o processo de agita??o das pastas. O aditivo dispersante reduziu consideravelmente os par?metros reol?gicos dos sistemas estudados. Os testes realizados com o controlador de filtrado e o retardador de pega tamb?m apresentaram propriedades adequadas para aplica??o como aditivos qu?micos em pastas para cimenta??o

Made available in DSpace on 2014-12-17T14:08:40Z (GMT). No. of bitstreams: 1 MariaRPF_DISSERT_partes_autorizadas.pdf: 435614 bytes, checksum: 36615dc20f70f58a222f546b112da5b2 (MD5) Previous issue date: 2009-12-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The production of heavy oil fields, typical in the Northeastern region, is commonly stimulated by steam injection. High bottom hole temperatures are responsible not only for the development of deleterious stresses of the cement sheath but also for cement strength retrogression. To overcome this unfavorable scenario, polymeric admixtures can be added to cement slurries to improve its fracture energy and silica flour to prevent strength retrogression. Therefore, the objective of the present study was to investigate the effect of the addition of different concentrations of polyurethane (5-25%) to cement slurries containing 40% BWOC silica flour. The resulting slurries were characterized using standard API (American Petroleum Institute) laboratory tests. In addition to them, the mechanical properties of the slurries, including elastic modulus and microhardness were also evaluated. The results revealed that density, free water and stability of the composite cement/silica/polyurethane slurries were within acceptable limits. The rheological behavior of the slurries, including plastic viscosity, yield strength and gel strength increased with the addition of 10% BWOC polyurethane. The presence of polyurethane reduced the fluid loss of the slurries as well as their elastic modulus. Composite slurries also depicted longer setting times due to the presence of the polymer. As expected, both the mechanical strength and microhardness of the slurries decreased with the addition of polyurethane. However, at high bottom hole temperatures, the strength of the slurries containing silica and polyurethane was far superior than that of plain cement slurries. In summary, the use of polyurethane combined with silica is an interesting solution to better adequate the mechanical behavior of cement slurries to heavy oil fields subjected to steam injection / Em campos que possuem ?leos pesados ? necess?rio um meio para estimular o ?leo a fluir pela forma??o, tais reservas s?o caracter?sticas da Regi?o Nordeste do Brasil e necessitam da inje??o de vapor para sua recupera??o. Temperatura elevada no fundo do po?o proporciona tens?es induzidas na bainha de cimento, al?m de favorecer a retrogress?o de resist?ncia do cimento, comprometendo a qualidade da cimenta??o. Sendo assim, adiciona-se em pastas cimentantes, o pol?mero, afim de se promover maior plasticidade e s?lica a para evitar o efeito da perda de resist?ncia mec?nica (retrogress?o). Diante disso, o presente trabalho teve como objetivo estudar o comportamento de pastas de cimento contendo poliuretana em diferentes concentra??es (5% a 25%) e 40% BWOC de s?lica flour. Foram realizados ensaios padronizados pelo API (American Petroleum Institute) e ensaios para obten??o do m?dulo de elasticidade e microdureza, al?m da caracteriza??o das pastas formuladas. Os resultados mostraram que as pastas comp?sitas cimento/s?lica/poliuretana apresentaram valores de peso espec?fico, ?gua livre e estabilidade dentro dos estabelecidos por norma. As propriedades reol?gicas foram modificadas, a viscosidade pl?stica, o limite de escoamento e os g?is aumentaram com a adi??o a partir de 10% BWOC de poliuretana. A poliuretana favoreceu melhor controle de filtrado e diminuiu o m?dulo de elasticidade das pastas. A mesma tamb?m promoveu retardamento da pega do cimento. As propriedades mec?nicas de resist?ncia e microdureza diminu?ram com a adi??o de s?lica e/ou s?lica/poliuretana, entretanto, em alta temperatura a resist?ncia mec?nica das pastas com s?lica e poliuretana tiveram um valor bem superior quando comparado com a pasta de cimento padr?o. A caracteriza??o das pastas mostrou que a adi??o de s?lica e pol?mero diminui o teor de c?lcio do cimento e que h? a forma??o do filme polim?rico. Pol?mero combinado com cimento e s?lica pode ser usado como aditivo para diminuir o m?dulo de elasticidade e, desta forma, fornecer maior plasticidade e resist?ncia ?s ciclagens t?rmicas ocasionadas pelo processo de inje??o de vapor

Made available in DSpace on 2014-12-17T14:07:09Z (GMT). No. of bitstreams: 1 Marcus VCB_DISSERT_PARCIAL.pdf: 2643130 bytes, checksum: 5d46e76949be4c4eb0ad9dfdafb24bcb (MD5) Previous issue date: 2013-02-18 / The materials engineering includes processes and products involving several areas of engineering, allowing them to prepare materials that fulfill the needs of various new products. In this case, this work aims to study a system composed of cement paste and geopolymers, which can contribute to solving an engineering problem that directly involves the exploitation of oil wells subject to loss of circulation. To correct it, has been already proposed the use of granular materials, fibers, reducing the drilling fluid or cement paste density and even surface and downhole mixed systems. In this work, we proposed the development of a slurry mixed system, the first was a cement-based slurry and the second a geopolymer-based slurry. The cement-based slurry was formulated with low density and extenders, 12.0 ppg (1.438 g/cm ?), showing great thixotropic characteristics. It was added nano silica at concentrations of 0.5, 1.0 and 1.5 gps (66.88, 133.76 and 200.64 L/m3) and CaCl2 at concentrations of 0.5, 1, 0 and 1.5%. The second system is a geopolymer-based paste formulated from molar ratios of 3.5 (nSiO2/nAl2O3), 0.27 (nK2O/nSiO2), 1.07 (nK2O/nAl2O3) and 13.99 (nH2O/nK2O). Finally, we performed a mixture of these two systems, for their application for correction of circulation lost. To characterize the raw materials, XRD, XRF, FTIR analysis and titration were performed. The both systems were characterized in tests based on API RP10B. Compressive strength tests were conducted after curing for 24 hours, 7 and 28 days at 58 ?C on the cement-based system and the geopolymer-based system. From the mixtures have been performed mixability tests and micro structural characterizations (XRD, SEM and TG). The results showed that the nano silica, when combined with CaCl2 modified the rheological properties of the cement slurry and from the concentration of 1.5 gpc (200.64 L / m?) it was possible to obtain stable systems. The system mixture caused a change in the microstructure of the material by favoring the rate of geopolymer formation to hinder the C3S phase hydration, thus, the production of CSH phases and Portlandite were harmed. Through the mixability tests it can be concluded that the system, due to reduced setting time of the mixture, can be applied to plug lost circulation zones when mixed downhole / A engenharia de materiais abrange processos e produtos envolvendo v?rias ?reas da engenharia, permitindo que sejam preparados materiais que atendam a v?rias necessidades de novos produtos. Neste caso, este trabalho tem por objetivo estudar um sistema de pasta composto por cimento e geopol?meros, que possa contribuir para a resolu??o de um problema de engenharia que envolve diretamente a explora??o de po?os de petr?leo sujeitos ? perda de circula??o. Para corrigi-la, j? foi proposto na literatura o uso de materiais granulares, fibrosos, redu??o da densidade do fluido de perfura??o ou pasta de cimento e at? mesmo sistemas mistos de fluidos misturados na superf?cie ou no fundo do po?o. Neste trabalho, foi proposto o desenvolvimento de um sistema misto de pastas, sendo o primeiro ? base de cimento Portland e o segundo ? base de geopol?mero. A pasta ? base de cimento, foi formulada com baixa massa espec?fica e aditivos extendedores, 12,0 lb/gal (1,438 g/cm?), apresentando grande car?ter tixotr?pico. Essa pasta foi aditivada com nanoss?lica, em concentra??es de 0,5; 1,0 e 1,5 gpc (66,88; 133,76 e 200,64 L/m3) e CaCl2, em concentra??es de 0,5; 1,0 e 1,5 %. A segunda pasta se constitui ? base de geopol?mero, sendo formulada a partir das raz?es molares de 3,5 (nSiO2/nAl2O3); 0,27 (nK2O/nSiO2); 1,07 (nK2O/nAl2O3) e 13,99 (nH2O/nK2O). E por fim, foi realizada a mistura desses dois sistemas, visando sua aplica??o para corre??o de perda de circula??o. Para caracterizar os precursores foram utilizadas as t?cnicas de DRX, FRX, FTIR e titula??o. Foram realizados os ensaios de caracteriza??o baseados na API RP10B para ambas as pastas puras. Ensaios de resist?ncia ? compress?o foram realizados ap?s a cura por 24 horas, 7 e 28 dias ? 58 ?C, para os sistemas de pasta de cimento e geopol?mero, separadamente. A partir das misturas, foi realizado o ensaio de misturabilidade e caracteriza??es microestruturais (DRX, TG e MEV). Os resultados mostraram que a nanoss?lica, quando combinada ao CaCl2 modificou as propriedades reol?gicas da pasta de cimento e a partir da concentra??o de 1,5 gpc (200,64 L/m?) foi poss?vel se obter sistemas est?veis. A mistura dos sistemas ocasionou uma modifica??o da microestrutura do material, atrav?s do favorecimento da rea??o de geopolimeriza??o em detrimento da hidrata??o da fase C3S, com isso, a produ??o das fases Portlandita e C-S-H foram prejudicadas. Atrav?s dos ensaios de misturabilidade, devido ao reduzido tempo de pega das misturas, pode-se concluir que o sistema misturado, pode ser aplicado para tamponar zonas de perda de circula??o quando misturado no fundo do po?o

Made available in DSpace on 2014-12-17T14:08:56Z (GMT). No. of bitstreams: 1 LuannaCMP_DISSERT.pdf: 3195149 bytes, checksum: 9c2b834c5beeb3439f6a0d1955159637 (MD5) Previous issue date: 2013-09-02 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Although there are a wide variety of additives that act in fresh state, to adjust the properties of cement, there is also a search by additions that improve the tenacity of the cement in the hardened state. This, in turn, can often be increased by inserting fibers, which act on the deflection of microcracks. This study aimed to use a microfiber glass wool (silica-based) as an additive reinforcing the cement matrix, improving the rupture tenacity, in order to prevent the propagation of microcracks in the cement sheath commonly found in oil wells submitted to high temperatures. The fibers were added at different concentrations, 2 to 5% (BWOC) and varied average sizes, grinding for 90 s, 180 s, 300 s, 600 s. The cement slurries were made with a density of 1,90 g/ cm3 (15,6 lb/gal), using Portland cement CPP- Special Class as the hydraulic binder and 40% silica flour. The characterization of the fiber was made by scanning electron microscopy (SEM), particle size by sieving, X-ray fluorescence (XRF), X-ray diffraction (XRD) and thermogravimetry (TG / DTG). Were performed technological tests set by the API (American Petroleum Institute) by rheology, stability, free water, compressive strength, as well as testing rupture energy, elastic modulus and permeability. The characterization results showed good thermal stability of the microfiber glass wool for application in oil wells submitted to steam injection and, also, that from the particle size data, it was possible to suggest that microfibers milled up to 300 s, are ideal to act as reinforcement to the cement slurries. The rheological parameters, there was committal of plastic viscosity when larger lengths were inserted of microfiber (F90). The values obtained by free water and stability were presented according to API. The mechanical properties, the incorporation of microfiber to the cement slurries gave better rupture tenacity, as compared to reference cement slurries. The values of compressive strength, elastic modulus and permeability have been maintained with respect to the reference cement slurries. Thus, cement slurries reinforced with microfiber glass wool can ensure good application for cementing oil wells submitted to steam injection, which requires control of microcracks, due to the thermal gradients / Embora exista uma grande variedade de aditivos que atuam no estado fresco, para ajuste das propriedades do cimento, existe tamb?m uma busca por adi??es que melhorem a tenacidade do cimento no estado endurecido. Esta, por sua vez, pode comumente ser aumentada pela inser??o de fibras, as quais agem na deflex?o de microtrincas. Este trabalho tem como objetivo utilizar microfibras de l? de vidro (? base de s?lica) como aditivo de refor?o ? matriz ciment?cia, melhorando a tenacidade ? ruptura, a fim de evitar a propaga??o de microfissuras na bainha cimentante comumente encontradas em po?os de petr?leo submetidos a altas temperaturas. As fibras foram adicionadas em diferentes teores, de 2 a 5% (BWOC), e variados tamanhos m?dios, obtidos variando o tempo de moagem de 90 s, 180 s, 300 s e 600 s. As pastas foram formuladas com densidade de 1,90 g/ cm3 (15,6 lb/gal), utilizando o cimento Portland CPP-Classe Especial como aglomerante hidr?ulico e 40% de s?lica flour. A caracteriza??o da fibra foi feita por microscopia eletr?nica de varredura (MEV), granulometria por peneiramento, fluoresc?ncia de raios X (FRX), difra??o de raios X (DRX) e termogravimetria (TG/DTG). Foram realizados ensaios tecnol?gicos padronizados pela API (American Petroleum Institute) de reologia, estabilidade, ?gua livre, resist?ncia ? compress?o, bem como testes de energia de ruptura, m?dulo de elasticidade e permeabilidade. Os resultados da caracteriza??o mostraram boa estabilidade t?rmica da microfibra de l? de vidro para aplica??o em po?os submetidos ? inje??o de vapor. A partir dos dados de granulometria, foi poss?vel verificar que microfibras mo?das at? 300 s s?o ideais para agirem como refor?o ? pasta de cimento. Dos par?metros reol?gicos, houve o comprometimento da viscosidade pl?stica quando foram inseridos comprimentos maiores de microfibra (F90). Os valores obtidos de ?gua livre e estabilidade se apresentaram conformes ? norma API. Das propriedades mec?nicas, a incorpora??o de microfibra ? pasta de cimento conferiu melhor tenacidade ? ruptura, comparada a pasta de refer?ncia. Os valores obtidos de resist?ncia ? compress?o, m?dulo de elasticidade e permeabilidade foram mantidos com rela??o ? pasta padr?o. Desse modo, pastas ciment?cias refor?adas com microfibra de l? de vidro podem garantir boas aplica??es em cimenta??o de po?os de petr?leo sujeitas ? inje??o de vapor, que exija o controle de microfissuras em virtude do gradiente de temperatura