Made available in DSpace on 2014-12-17T14:06:55Z (GMT). No. of bitstreams: 1 CarinaGMM_DISSERT.pdf: 2881294 bytes, checksum: 3b5fb2cb077e76e3477ec04b95724ee5 (MD5) Previous issue date: 2009-12-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / One of the major current challenges for oilwell companies is the extraction of oil from evaporitic zones, also known as pre-salt basins. Deep reservoirs are found under thick salt layers formed from the evaporation of sea water. Salt layers seal the flow of oil from underneath rock formations, which store hydrocarbons and increase the probability of success in oil and gas exploration. Oilwells are cemented using Portland-based slurries to promote mechanical stability and zonal isolation. For pre-salt oilwells, NaCl must be added to saturate the cement slurries, however, the presence of salt in the composition of slurries affects their overall behavior. Therefore, the objective of the present study was to evaluate the effect of the addition of 5 to 25% NaCl on selected properties of Portland-based slurries. A series of tests were carried out to assess the rheological behavior, thickening time, free water and ultrassonic compressive strength. In addition, the slurries were also characterized by thermal analysis, X ray diffraction and scanning electron microscopy. The results showed that the addition of NaCl affected the thickening time of the slurries. NaCl contents up to 10% shortened the thickening time of the slurries. On the other hand, concentrations in excess of 20% not only extended the thickening time, but also reduced the strength of hardened slurries. The addition of NaCl resulted in the formation of a different crystalline phase called Friedel?s salt, where free chlorine is bonded to tricalcium aluminate / Atualmente, um dos grandes desafios para as empresas petrol?feras ? a explora??o de petr?leo em bacias dominadas por estruturas salinas, mais conhecidas por zonas evapor?ticas. A camada de sal ? formada pela evapora??o da ?gua do mar, cuja composi??o qu?mica inclui altas concentra??es de cloreto de s?dio (NaCl). Reservat?rios profundos s?o encontrados abaixo de espessas camadas de sal que vedam o fluxo de ?leo para fora da rocha, aprisionando hidrocarbonetos e aumentando, assim, a probabilidade de sucesso na prospec??o de ?leo e g?s. Atendendo ?s condi??es de po?o, s?o utilizadas pastas de cimento do tipo Portland para isolar, promover resist?ncia mec?nica ao po?o e impedir a intercomunica??o zonal das forma??es rochosas produtoras. Deste modo, as pastas de cimento devem atender ?s necessidades do sal, pois este se encontra na natureza com distintas caracter?sticas. Assim, este trabalho teve como objetivo avaliar o comportamento de sistemas de pastas saturadas com NaCl, em concentra??es de 5% a 25%, frente as propriedades f?sicas e qu?micas das mesmas. Tais propriedades foram analisadas atrav?s de ensaios laboratoriais de reologia, tempo de espessamento, ?gua livre e resist?ncia ? compress?o (UCA), bem como com o uso de t?cnicas de caracteriza??o t?rmica, difra??o de raios X e microscopia eletr?nica de varredura. Os resultados mostraram que a presen?a do NaCl, quando em pequenas concentra??es (at? 10%) atua como acelerador de pega. J? quando em altas concentra??es (a partir de 20%), n?o s? apresenta efeito oposto em rela??o ? pega, retardando-a, bem como atua deleteriamente na resist?ncia ? compress?o. Foi observada, tamb?m, a forma??o de uma nova fase denominada sal de Friedel, resultado da liga??o dos cloretos livres ao aluminato tric?lcico, incorporado ?s fases s?lidas do cimento hidratado

Made available in DSpace on 2014-12-17T14:06:56Z (GMT). No. of bitstreams: 1 AnaCeciliaVN.pdf: 4627476 bytes, checksum: 03aa7ea0e615f64c7e42bf3a39bdd226 (MD5) Previous issue date: 2008-04-25 / Portland-polymers composites are promising candidates to be used as cementing material in Northeastern oil wells of Brazil containing heavy oils submitted to steam injection. In this way, it is necessary to evaluate its degradation in the commonly acidizind agents. In addition, to identify how aggressive are the different hostile environments it is an important contribution on the decision of the acidic systems to be used in. It was investigated the performance of the Portland-polymer composites using powdered polyurethane, aqueous polyurethane, rubber tire residues and a biopolymer, those were reinforced with polished carbon steel SAE 1045 to make the electrochemical measurements. HCl 15,0 %, HCl 6,0 % + HF 1,5 % (soft mud acid), HCl 12,0 % + HF 3,0 % (regular mud acid) and HAc 10 % + HF 1,5 % were used as degrading environment and electrolytes. The more aggressive acid solution to the plain Portland hardened cement paste was the regular mud acid, that showed loss of weight around 23.0 %, followed by the soft mud acid, the showed 11.0 %, 15.0 % HCl with 7,0 % and, at last the 10.0 % HAc plus HF 1.5 % with just 1.0 %. The powdered polyurethane-composite and the aqueous polyurethane one showed larger durability, with reduction around 87.0 % on the loss of weight in regular mud acid. The acid attack is superficial and it occurs as an action layer, where the degraded layer is responsible for the decrease on the kinetic of the degrading process. This behavior can be seen mainly on the Portland- aqueous polyurethane composite, because the degraded layer is impregnated with chemically modified polymer. The fact of the acid attack does not have influence on the compressive strength or fratography of the samples, in a general way, confirms that theory. The mechanism of the efficiency of the Portland-polymers composites subjected to acid attack is due to decreased porosity and permeability related with the plain Portland paste, minor quantity of Ca+2, element preferentially leached to the acidic solution, wave effect and to substitute part of the degrading bulk for the polymeric one. The electrolyte HAc 10 % + HF 1,5 % was the least aggressive one to the external corrosion of the casing, showing open circuit potentials around +250 mV compared to -130 mV to the simulated pore solution to the first 24 hours immersion. This behavior has been performed for two months at least. Similar corrosion rates were showed between both of the electrolytes, around 0.01 μA.cm-2. Total impedance values, insipient arcs and big polarization resistance capacitive arcs on the Nyquist plots, indicating passivity process, confirm its efficiency. In this way, Portlandpolymers composites are possible solutions to be succeed applied to oilwell cementing concomitant submitted to steam injection and acidizing operation and the HAc 10,0 % + HF 1,5 % is the less aggressive solution to the external corrosion of the casing / Comp?sitos Portland-pol?meros s?o promissores candidatos ? cimenta??o de po?os de petr?leo contendo ?leos pesados submetidos ? inje??o de vapor nos campos do Nordeste do Brasil. Assim, faz-se necess?rio avaliar sua degrada??o frente aos ?cidos comumente utilizados em opera??es de acidifica??o. Al?m disso, identificar a agressividade dos diferentes meios hostis ? corros?o externa do revestimento constitui uma importante contribui??o na decis?o dos sistemas ?cidos a serem utilizados. Foram avaliados comp?sitos adicionados de poliuretana em p?, poliuretana em solu??o aquosa, borracha de pneu mo?da e um biopol?mero atrav?s das API Spec. 10, sendo refor?ados com a?o carbono polido SAE 1045 para os ensaios eletroqu?micos. HCl 15,0 %, HCl 6,0 % + HF 1,5 % (soft mud acid), HCl 12,0 % + HF 3,0 % (regular mud acid) e HAc 10,0 % + HF 1,5 % foram aplicadas como meios degradantes e eletr?litos. A solu??o ?cida mais agressiva ? pasta de cimento Portland convencional ? a regular mud acid, que apresenta perda de massa em torno de de 23,0 %, seguida da soft mud acid, com perda de massa de 11,0 % e da solu??o HCl 15,0 %, em torno de 7,0 %. As menores perdas de massa, no entanto, s?o relativas ao meio agressivo HAc 10,0 % + HF 1,5 %, com perdas no patamar de 1,0 %. Os comp?sitos com poliuretana em p? e poliuretana em solu??o aquosa apresentaram maior durabilidade, com redu??o em torno de 87,0 % na perda de massa frente ao regular mud acid. O ataque ?cido ? superficial e ocorre como uma frente de a??o, sendo a camada degradada respons?vel pela minimiza??o da cin?tica do processo de degrada??o, principalmente no comp?sito Portland-poliuretana em dispers?o aquosa, por ser impregnada por pol?mero quimicamente modificado. O fato de n?o haver, de uma forma geral, influ?ncia do ataque ?cido na resist?ncia ? compress?o e fratografia das amostras, ap?s ataque ?cido, ratifica essa teoria. O mecanismo da maior efici?ncia dos comp?sitos Portland-pol?meros frente ao ataque ?cido ? regido por menores porosidades e permeabilidades que a pasta de cimento convencional, menor quantidade de Ca+2, elemento prioritariamente lixiviado para a solu??o ?cida, efeito tortuosidade e substitui??o de massa degrad?vel por massa polim?rica. O eletr?lito HAc 10,0 % + HF 1,5 % foi o menos agressivo ? corros?o externa do revestimento, com potenciais de circuito aberto superiores ? solu??o simuladora dos poros como eletr?lito, +250 mV frente a -130 mV para as primeiras 24 horas de imers?o, mantendo esse comportamento ao longo de, pelo menos, 2 meses de imers?o. Correntes de corros?o semelhantes entre esses dois eletr?litos, em torno de 0,01 μA.cm-2, e valores de imped?ncia total, arcos incipientes e grandes arcos capacitivos de resist?ncia de polariza??o, indicadores de passiva??o nos diagramas de Nyquist, confirmam sua efici?ncia. Assim, comp?sitos Portland-pol?meros s?o solu??es poss?veis de serem empregadas em cimenta??o de po?os de petr?leo submetidos concomitantemente ? inje??o de vapor e opera??es de acidifica??o, sendo a solu??o HAc 10,0 % + HF 1,5 % menos agressiva ? corros?o externa do revestimento ap?s opera??es de acidifica??o

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 2014-12-17T14:07:05Z (GMT). No. of bitstreams: 1 DiegoBR_DISSERT.pdf: 2561284 bytes, checksum: 728dce6008fc70c37faa4759ea2eba6d (MD5) Previous issue date: 2012-02-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Nowadays, the search for new technologies that are able to follow the upcoming challenges in oil industry is a constant. Always trying properties improvements of the used materials, looking for the best performance and greater life time. Besides the search for technologies that show an improvement of performance, the search for materials environmentally correct along the whole production process. In Oil well cementing, this search for new technologies passes through the development of slurry systems that support these requests and that are also environmentally friendly. In this context, the use of geopolymer slurries is a great alternative route to cementing oil wells. Besides having good properties, comparable to Portland cement slurries, this alternative material releases much less CO2 gas in the production of their root materials when compared the production of Portland cement, which releases tons of CO2. In order to improve the properties of geopolymer slurries has been added Calcium Oxide, as observed in other studies that slurries where the Calcium is present the values of compressive strength is greater. The addition has been realized based in the CaO/SiO2 molar ratio of 0.05, 0.10 and 0.15. Have been performed compressive strength tests, thickening time, rheology and fliud loss control test of the slurries, following NBR 9831, as well as the physical chemical characterization of XRD, SEM and TG. Has been observed in most of the tests the slurries follow a tendency until the ratio of 0.10, which inverses in the ratio 0.15. This behavior can be explained by two phenomena that occur simultaneously, the first one is the break of the polymer chains and a consequent increase in molucules mobility, which prevails until the ratio of 0.1, and the second is possible approach of the chains due to the capacity of the calcium ions stabilize the charges of two different aluminum. There is only one linearity in the mechanical behavior that can be attributed to the appereance of the C-S-H phase. Based on this, it is concluded that the phenomenon of breaking the polymer chains predominates until the ratio of 0.1, causing an increase of the filtrate volume, lower rheological parameters and increasing thickening time. From the ratio of 0.15 the approach of the chains predominates, and the behavior is reversed / Nos dias atuais a busca por novas tecnologias que possam acompanhar os desafios que surgem dia a dia na ind?stria do petr?leo ? constante, sempre tentando melhorar as propriedades dos materiais que s?o utilizados, buscando o melhor desempenho e maior vida ?til. Al?m de buscar novas tecnologias ? de fundamental import?ncia o desempenho dos materiais e que estes sejam ambientalmente corretos. No ramo da cimenta??o de po?os de petr?leo, essa procura por novas tecnologias passa pelo desenvolvimento de sistemas de pastas que suportem as solicita??es requeridas pelas normas internacionais e nacionais para esse setor. Nesse contexto, lan?a o desafio de se produzir novos sistemas de pastas para o revestimento de po?os petrol?feros, sejam eles para po?os on shore ou off shore. As pastas geopolim?ricas apresentam-se como uma boa alternativa para a cimenta??o de po?os de petr?leo, pois alem de possuir boas propriedades, compar?veis as pastas de cimento Portland, esse material libera muito menos CO2 na produ??o das suas meterias primas quando comparados ? produ??o do cimento Portland. Com o intu?do de melhorar as propriedades das pastas geopolim?ricas foi adicionado o ?xido de c?lcio, pois foi observado em outros trabalhos que pastas onde o c?lcio esta presente os valores de resist?ncia a compress?o s?o maiores. A adi??o foi realizada baseada na raz?o molar CaO/SiO2 de 0,05, 0,10 e 0,15, foram realizados ensaios de resist?ncia a compress?o, tempo de espessamento, reologia e filtrado das pastas seguindo a NBR 9831, bem como as caracteriza??es f?sico qu?micas de DRX, MEV, TG. Foi observado que na maioria dos ensaios as pastas seguem uma tend?ncia ate a raz?o de 0,10 que se inverte na raz?o de 0,15. Esse comportamento pode ser explicado por dois fen?menos que ocorrem simultaneamente: o primeiro ? a quebra das cadeias polim?ricas com um conseq?ente aumento da mobilidade das mol?culas, que prevalece ate a raz?o de 0,1, e o segundo ? a poss?vel aproxima??o das cadeias devido a capacidade do ?on c?lcio estabilizar as cargas de dois alum?nios diferentes. Existe apenas a linearidade no comportamento mec?nico que pode ser atribu?do ao aparecimento da fase C-S-H. Com base nisso pode se concluir que o fen?meno de quebra das cadeias polim?ricas predomina at? a raz?o de 0,1, provocando o aumento no volume de filtrado, diminui??o dos par?metros reol?gicos e aumento do tempo de espessamento. A partir da raz?o 0,15 a aproxima??o das cadeias predomina e assim o comportamento se inverte

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 2014-12-17T14:07:08Z (GMT). No. of bitstreams: 1 EricaNMGP_TESE.pdf: 149123 bytes, checksum: d13a2a775b94d69d52d9e403106d2117 (MD5) Previous issue date: 2011-06-01 / The development of activities the of oil and gas sector have promoted the search for suitable materials for cementing oil wells. In the state of the Rio Grande do Norte, the integrity of the cement sheath tends to be impaired during steam injection, a procedure necessary to increase oil recovery in reservoirs with low-viscosity oil. The geopolymer is a material that can be used as alternative cement, since it has been used in the production of fire-resistant components, building structures, and for the control of toxic or radioactive residues. Geopolymers result from condensation polymer alkali aluminosilicates and silicates resulting three-dimensional polymeric structures. They are produced in a manner different from that of Portland cement, which is made an activating solution that is mixed with geopolymer precursor. Among the few works studied allowed us to conclude that the pastes prepared with metakaolin as precursor showed better performance of its properties. Several studies show the addition of waste clay as a means of reducing cost and improving end of the folder properties. On this basis, the goal is to study the influence of the addition of ceramic waste in geopolymer paste. To develop the study of rheology tests were carried out, filtered, thickening time, compressive strength, free water, specific gravity and permeability, according to the American Pretoleum Institute (API). The results for all formulations studied show that the folders have high mechanical strength to a light paste; low filtrate volume, absence of free water, very low permeability, slurry, consistent with a light paste, and thickening time low that can be corrected with the use of a retardant handle. For morphological characterization, microstructural, physical, chemical and thermal tests were carried out by XRD, MEV, DTA, TG, FTIR. In the trial of XRD, it was found that geopolymer is an amorphous material, with a peak of crystalline kaolinite. In tests of TG / DTA, revealed the presence of a significant event, which represents the mass loss related to water, and also observed the reduction of weight loss by increasing the concentration of ceramic waste. In the trial of MEV, we found a uniform matrix without the presence of other phases. In the trial of FT-IR, we observed the presence of the band related to water. From all results it was determined that the optimum concentration range of use is between 2.5 and 5% of waste ceramic / O desenvolvimento das atividades do setor de petr?leo e g?s tem promovido a busca de materiais mais adequados para cimenta??o de po?os de petr?leo. No estado do RN, a integridade da bainha cimentante tende a ser prejudicada durante a inje??o de vapor, procedimento necess?rio para aumentar a recupera??o do petr?leo em reservat?rios com ?leo de alta viscosidade. O geopol?mero ? um material que pode ser utilizado como cimento alternativo, uma vez que vem sendo empregado na produ??o de componentes resistentes ao fogo, na constru??o de estruturas, e para o controle de res?duos t?xicos ou radioativos. Geopol?meros resultam da condensa??o polim?rica de aluminosilicatos e silicatos alcalinos originando estruturas polim?ricas tridimensionais. S?o produzidos de uma maneira distinta daquela do cimento Portland, onde ? feita uma solu??o ativadora que ? misturada ao precurssor geopolim?rico. Dentre os trabalhos estudados, alguns permitiram-nos concluir que as pastas preparadas com metacaulim como precursor apresentaram melhor desempenho de suas propriedades. V?rios estudos apresentam a adi??o de res?duos argilosos como forma de redu??o do custo final e melhoria das propriedades da pasta. Com base nisso, o objetivo do trabalho ? estudar a influ?ncia da adi??o de rejeito cer?mico em pastas geopolim?ricas. Para o desenvolvimento do estudo foram realizados testes de reologia, filtrado, tempo de espessamento, resist?ncia ? compress?o, ?gua livre, peso espec?fico e permeabilidade, de acordo com o American Pretoleum Institute (API). Os resultados encontrados para todas as formula??es demonstram que as pastas estudadas apresentam resist?ncia mec?nica elevada para uma pasta leve; volume de filtrado baixo; aus?ncia de ?gua livre; permeabilidade muito baixa; pasta flu?da, coerente com uma pasta leve; e tempo de espessamento baixo, que pode ser corrigido com a utiliza??o de um retardador de pega. Para caracteriza??o morfol?gica, microestrutural, f?sico-qu?mica, qu?mica e t?rmica, foram realizadas caracteriza??es por DRX, MEV, DTA, TG, FT-IR. No ensaio de DRX, verificou-se que o geopol?mero ? um material amorfo, com um pico cristalino de caulinita. Nos testes de TG/DTA, foi observado a presen?a de um evento significativo, que representa a perda de massa referente a ?gua, sendo observado tamb?m a redu??o da perda de massa com o aumento da concentra??o de rejeito cer?mico. No ensaio de MEV, encontrou-se uma matriz uniforme e nos espectros de FT-IR, observou-se a presen?a da banda referente ? ?gua. A partir de todos os resultados foi poss?vel determinar que a faixa de concentra??o ?tima de rejeito cer?mico para uso em pastas geopolim?ricas ? entre 2,5 e 5 %

Made available in DSpace on 2014-12-17T14:07:08Z (GMT). No. of bitstreams: 1 ManoelIQJ_DISSERT.pdf: 1658589 bytes, checksum: 30023fa8ec2e11231777b5b0249ad3cc (MD5) Previous issue date: 2013-05-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The oil wells cementing is a critical step during the phase of well drilling, because problems during the operation of slurry pumping and an incomplete filling of the annular space between the metal casing and the formation can cause the slurry loss. Therefore, the slurry adopted in primary cementing an oil well must be properly dosed so that these problems are avoided during its pumping. When you drill a well in a weak rock formation requires even more careful, because should be a limit of hydrostatic pressure exerted during cementation, that does not occur rock collapse. With the objective of performing the cementing of a well whose formation is weak or unconsolidated are employed lighter slurries. Thus, this study used slurries with sodium silicate and nano silica in concentrations of 0,1; 0,4; 0,7 e 1,0 gpc, in which the slurries with nano silica showed the rheological parameters higher concentrations of up to 0.7 gpc and for concentration of 1.0 the slurry with sodium silicate obtained the highest values, remaining above the limits for application in fields, mainly wells with low fracture gradient, because a significant increase in viscosity may result in an increase in pressure pumping in operations of secondary cementations. Furthermore, there was no decrease in strength with increasing concentration of additive. Then, it is possible use of these additives to formulate Lighter slurry / A cimenta??o de po?os de petr?leo ? uma das etapas mais criticas durante a fase de perfura??o de um po?o, pois problemas durante a opera??o de bombeio da pasta e um preenchimento incompleto do espa?o anular, entre o revestimento e a parede do po?o, podem causar a perda do mesmo. Portanto, a pasta adotada na cimenta??o prim?ria de um po?o de petr?leo deve ser calculada adequadamente para que sejam evitados estes problemas durante seu bombeamento. Ao se perfurar um po?o em uma forma??o rochosa fraca requer-se, ainda, mais cuidado, pois, em geral, deve existir um limite de press?o hidrost?tica exercida durante a cimenta??o, para que n?o haja o colapso da forma??o. Com o objetivo de se realizar a cimenta??o de um po?o cuja forma??o ? fraca ou inconsolidada s?o empregadas pastas leves. Desta forma, neste trabalho foram utilizadas pastas com silicato de s?dio e nano s?lica em concentra??es de 0,1; 0,4; 0,7 e 1,0 gpc, onde as pastas com nano s?lica apresentaram os par?metros reol?gicos superiores at? a concentra??o de 0,7 gpc e para a concentra??o de 1,0 gpc a pasta com silicato de s?dio obteve os maiores valores, ficando acima dos limites estabelecidos para aplica??o em campos, principalmente em po?os com baixo gradiente de fratura, pois o aumento significativo da viscosidade pode resultar no incremento da press?o de bombeio em opera??es de recimenta??o. Al?m disto, n?o foi observado em decr?scimo de resist?ncia mec?nica com aumento de concentra??o dos aditivos. Sendo poss?vel utiliza??o destes aditivos para formula??o de pastas leves

Made available in DSpace on 2014-12-17T14:07:12Z (GMT). No. of bitstreams: 1 UlissesTB.pdf: 2103703 bytes, checksum: 784868c57be7336a1a7601f71664ac81 (MD5) Previous issue date: 2006-10-31 / The oil production in mature areas can be improved by advanced recovery techniques. In special, steam injection reduces the viscosity of heavy oils, thus improving its flow to surrounding wells. On the other hand, the usually high temperatures and pressures involved in the process may lead to cement cracking, negatively affecting both the mechanical stability and zonal isolation provided by the cement sheath of the well. The addition of plastic materials to the cement is an alternative to prevent this scenario. Composite slurries consisting of Portland cement and a natural biopolymer were studied. Samples containing different contents of biopolymer dispersed in a Portland cement matrix were prepared and evaluated by mechanical and rheological tests in order to assess their behavior according to API (American Petroleum Institute) guidelines. FEM was also applied to map the stress distribution encountered by the cement at bottom bole. The slurries were prepared according to a factorial experiment plan by varying three parameters, i.e., cement age, contents of biopolymer and water-to-cement ratio. The results revealed that the addition of the biopolymer reduced the volume of free water and the setting time of the slurry. In addition, tensile strength, compressive strength and toughness improved by 30% comparing hardened composites to plain Portland slurries. FEM results suggested that the stresses developed at bottomhole may be 10 to 100 times higher than the strength of the cement as evaluated in the lab by unconfined mechanical testing. An alternative approach is proposed to adapt the testing methodology used to evaluate the mechanical behavior of oilwell cement slurries by simulating the confined conditions encountered at bottornhole / A cimenta??o de po?os ? pr?tica comum na ind?stria do petr?leo. Po?os antigos que apresentam baixo rendimento passam a produzir mais quando se adota o processo de recupera??o secund?ria. Um dos procedimentos que pode ser adotado nestes po?os ? a introdu??o de vapor d'?gua sob press?o para que o petr?leo tenha sua viscosidade reduzida e flua com mais facilidade para os po?os da circunvizinhan?a. A temperatura elevada provoca fissura??o nas bainhas dos po?os e conseq?ente perda de estanqueidade devido ao car?ter r?gido das bainhas de cimento Portland. Comp?sitos de cimento Portland aditivados com biopol?mero foram analisados com rela??o a tr?s aspectos: propriedades mec?nicas previstas nas normas da ABNT e espec?ficas para a ind?stria do petr?leo; propriedades reol?gicas tamb?m previstas em norma e avalia??o num?rica por elementos finitos simulando bainhas de po?os de petr?leo. As pastas foram preparadas seguindo planejamento fatorial pr?vio, com varia??o de tr?s fatores: idade do cimento Portland, concentra??o de biopol?mero e fator ?gua/cimento. Os resultados mostraram que a presen?a do biopol?mero elimina forma??o de ?gua livre; funciona como acelerador de pega, reduzindo o tempo de espessamento; aumenta as resist?ncias ? compress?o e ? tra??o em at? 30 % e a tenacidade-resili?ncia em at? 30 %. A an?lise por elementos finitos mostrou que a ordem de grandeza das tens?es despertadas pela temperatura no fundo do po?o chega a ser 10 e 100 vezes superior ?s resist?ncias ? compress?o e ? tra??o, respectivamente, das pastas ensaiadas em laborat?rio. Isto levou ? constata??o de que os ensaios n?o confinados de propriedades mec?nicas n?o conseguem medir o comportamento real das pastas, sendo necess?ria a adapta??o dos mesmos para a condi??o confinada. Um ensaio alternativo ? proposto por meio de um equipamento (SCERB) que simula as condi??es de fundo de po?o

Made available in DSpace on 2014-12-17T14:07:17Z (GMT). No. of bitstreams: 1 FlankML.pdf: 1510639 bytes, checksum: 80a343cff9d15e912e4b6cbd66703104 (MD5) Previous issue date: 2006-10-16 / The isolation of adjacent zones encountered during oilwell drilling is carried out by Portland-based cement slurries. The slurries are pumped into the annular positions between the well and the casing. Their rheological behavior is a very important component for the cementing process. Nowadays, several alternative materials are used in oilwell cementing, with goal the modification and the improvement of their properties, mainly the increase of the fluidity. And this can be reached by using plasticizers additives able to account for different oilwell conditions, yielding compatible cement slurries and allowing enough time for the complete cementing operation. If the rheological properties of the slurry are properly characterized, the load loss and flow regime can be correctly predicted. However, this experimental characterization is difficult. Rheological models capable of describing the cement slurry behavior must be capable of predicting the slurry cement deformation within reasonable accuracy. The aim of this study was to characterize rheologically the slurries prepared with a especial class of Portland cement, water and plasticizers based on lignosulfonate, melamine and polycarboxylate at temperatures varying from 27?C to 72?C. The tests were carried out according to the practical recommendations of the API RP 10B guidelines. The results revealed a great efficiency and the dispersive power of the polycarboxylate, for all temperatures tested. This additive promoted high fluidity of the slurries, with no sedimentation. High lignosulfonate and melamine concentrations did not reduce the rheological parameters (plastic viscosity and yield stress) of the slurries. It was verified that these additives were not compatible with the type of cement used. The evaluated rheological models were capable of describing the behavior of the slurries only within concentration and temperature ranges specific for each type of additive / Pastas de cimento do tipo Portland s?o usadas para isolamento de po?os de petr?leo. Esse procedimento ? realizado por meio do bombeio da pasta no espa?o anular entre o po?o e a coluna de revestimento, de modo a se obter fixa??o e veda??o eficiente e permanente. Para isso o comportamento reol?gico da pasta de cimento ? um componente de extrema import?ncia para o processo de cimenta??o. Atualmente, diversos materiais alternativos s?o utilizados em pastas para cimenta??o, objetivando a modifica??o e a melhoria de suas propriedades, principalmente no que diz respeito ao aumento de fluidez. Isso pode ser alcan?ado por meio da utiliza??o de novos aditivos do tipo plastificantes, capazes de suportar as diversas condi??es de po?os, promovendo ?s pastas propriedades compat?veis ?s condi??es encontradas, permitindo, ainda, um tempo suficiente de trabalhabilidade para a completa execu??o do servi?o de cimenta??o. Assim, se as propriedades reol?gicas da pasta s?o bem caracterizadas, a perda de carga e o regime de fluxo podem ser prognosticados corretamente. Contudo, essa caracteriza??o ? dif?cil do ponto de vista experimental. Modelos reol?gicas capazes de descrever o que ocorre, dever?o ser capazes de predizer a deforma??o da pasta de cimento com razo?vel exatid?o. Portanto, a finalidade deste trabalho foi o estudo e a caracteriza??o reol?gica de pastas constitu?das de cimento Portland classe especial, ?gua e aditivos do tipo plastificante, a base de lignossulfonato, melamina e policarboxilato, em temperaturas na faixa de 27?C a 72?C. Os testes foram realizados de acordo com as recomenda??es pr?ticas da norma API RP 10B. Os resultados dos ensaios demonstraram a grande efici?ncia e o poder dispersivo do policarboxilato, para todas as temperaturas estudadas. O aditivo promoveu uma alta fluidez, sem efeitos de sedimenta??o. O aumento das concentra??es de lignossulfonato e melamina n?o reduziu os par?metros reol?gicos (viscosidade pl?stica e limite de escoamento). Tamb?m foi verificado que esses aditivos n?o foram compat?veis com o tipo de cimento utilizado. Por fim, os modelos reol?gicos avaliados foram capazes de descrever o comportamento das pastas apenas para faixas de temperatura e concentra??o de cada tipo de aditivo

Made available in DSpace on 2014-12-17T14:08:29Z (GMT). No. of bitstreams: 1 JulioCOF.pdf: 983441 bytes, checksum: df3a42267608b9d7ed2fd356c7ba1094 (MD5) Previous issue date: 2008-07-16 / Chemical admixtures, when properly selected and quantified, play an important role in obtaining adequate slurry systems for quality primary cementing operations. They assure the proper operation of a well and reduce costs attributed to corrective cementing jobs. Controlling the amount lost by filtering through the slurry to permeable areas is one of the most important requirements in an operation, commonly controlled by chemical admixtures, such as carboxymethylcellulose (CMC). However, problems related to temperature, salttolerance and the secundary retarding effect are commonly reported in the literature. According to the scenario described above, the use of an aqueous dispersion of non-ionic poliurethane was proposed to control the filter loss, given its low ionic interaction with the free ions present in the slurries in humid state. Therefore, this study aims at assessing the efficiency of poliurethane to reduce filter loss in different temperature and pressure conditions as well as the synergistic effect with other admixtures. The temperatures and pressures used in laboratory tests simulate the same conditions of oil wells with depths of 500 to 1200 m. The poliurethane showed resistance to thermal degradation and stability in the presence of salts. With the increase in the concentration of the polymer there was a considerable decrease in the volume lost by filtration, and this has been effective even with the increase in temperature / Os aditivos qu?micos, quando devidamente selecionados e quantificados, s?o importantes aliados na obten??o de sistemas adequados de pastas para cimenta??es prim?rias de qualidade, fundamentais para o ciclo de vida ?til de um po?o, visto que opera??es de cimenta??o corretiva geram custos adicionais. Controlar a quantidade perdida por filtra??o pela pasta de cimento para as zonas perme?veis ? um dos requisitos mais importantes em uma opera??o, comumente controlado por aditivos qu?micos, como a carboximetilcelulose (CMC). Entretanto, problemas associados ? temperatura, toler?ncia a sais e o efeito secund?rio como retardador de pega, s?o comumente reportados na literatura. De acordo com o cen?rio descrito acima foi proposta a utiliza??o de uma dispers?o aquosa n?o i?nica de poliuretana para controle de filtrado, dada sua baixa intera??o i?nica com os ?ons livres presentes na pasta no estado fresco. Assim, este trabalho tem como objetivo avaliar a efici?ncia da poliuretana como redutor de filtrado em diferentes condi??es de temperatura e press?o, bem como o efeito sin?rgico com outros aditivos. As temperaturas e press?es utilizadas nos ensaios em laborat?rio simulam as mesmas condi??es de po?os de petr?leo com profundidades de 500 a 1200 m. A poliuretana apresentou resist?ncia ? degrada??o t?rmica e estabilidade na presen?a de sais. Com o aumento da concentra??o do pol?mero observou-se uma consider?vel diminui??o do volume perdido por filtra??o, mantendo-se eficiente mesmo com o incremento da temperatura