Made available in DSpace on 2014-12-17T14:06:57Z (GMT). No. of bitstreams: 1 AntonioNF_DISSERT.pdf: 3720151 bytes, checksum: 9b23d51efb071c929717b8ea4387b379 (MD5) Previous issue date: 2011-06-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Physical-chemical properties of Ti are sensible to the presence of interstitial elements. In the case of thermochemical treatments plasma assisted, the influence of different active species is not still understood. In order to contribute for such knowledge, this work purposes a study of the role played by the active species atmosphere into the Ar N2 CH4 carbonitriding plasma. It was carried out a plasma diagnostic by OES (Optical Emission Spectroscopy) in the z Ar y N2 x CH4 plasma mixture, in which z, y and x indexes represent gas flow variable from 0 to 4 sccm (cm3/min). The diagnostic presents abrupt variations of emission intensities associated to the species in determined conditions. Therefore, they were selected in order to carry out the chemical treatment and then to investigate their influences. Commercial pure Ti disks were submitted to plasma carbonitriding process using pre-established conditions from the OES measurements while some parameters such as pressure and temperature were maintained constant. The concentration profiles of interstitial elements (C and N atoms) were determined by Resonant Nuclear Reaction Analysis (NRA) resulting in a depth profile plots. The reactions used were 15N(ρ,αγ)12C and 12C(α,α)12C. GIXRD (Grazing Incidence X-Ray Diffraction) analysis was used in order to identify the presence of phases on the surface. Micro-Raman spectroscopy was used in order to qualitatively study the carbon into the TiCxN1 structure. It has been verified which the density species effectively influences more the diffusion of particles into the Ti lattice and characteristics of the layer formed than the gas concentration. High intensity of N2 + (391,4 nm) and CH (387,1 nm) species promotes more diffusion of C and N. It was observed that Hα (656,3 nm) species acts like a catalyzer allowing a deeper diffusion of nitrogen and carbon into the titanium lattice. / As propriedades f?sico-qu?micas do Ti s?o sens?veis ? presen?a de intersticiais. No caso do tratamento termoqu?mico auxiliado por plasma, a influ?ncia das diferentes esp?cies ativas ainda n?o ? bem entendida. A fim de colaborar para tal conhecimento, esse trabalho prop?e um estudo das esp?cies ativas do plasma carbonitretante de N2+Ar+CH4. Foi realizado o diagn?stico por espectroscopia de emiss?o ?ptica (OES) do plasma na mistura xAr+yN2+zCH4, onde x, y e z s?o fluxos vari?veis de 0 a 4 sccm (cm3/min.). Esse diagn?stico apresentou varia??es abruptas de intensidades de emiss?o das esp?cies em determinadas condi??es e estas foram selecionadas para realizar o tratamento termoqu?mico e assim investigar suas influ?ncias. Em seguida, discos de Ti comercialmente puros foram submetidos ao processo de carbonitreta??o por plasma com as condi??es pr?-estabelecidas pelo diagn?stico de plasma enquanto que os par?metros de press?o e temperatura foram mantidos constantes. O perfil de concentra??o dos intersticiais, carbono e nitrog?nio, foi determinado por rea??o nuclear ressonante (NRA) resultando numa curva de perfil em profundidade. As rea??es usadas foram 15N(ρ,αγ)12C e 12C(α,α)12C. Utilizou-se difra??o de raios-X em ?ngulo rasante (GIDRX) para identificar as fases presentes na superf?cie. A espectroscopia micro-Raman foi usada para estudar, de forma qualitativa a estrutura do carbono no TiCxN1-xVerificou-se que a densidade das esp?cies influencia, de maneira mais efetiva que o fluxo de g?s, no processo de difus?o e nas caracter?sticas da camada formada. Alta intensidade das esp?cies N2 + (391,4 nm) e CH (387,1 nm) favorecem a difus?o dos intersticiais C e N. Foi observado que o Hα (656,3 nm) atua como catalisador permitindo a difus?o em maiores profundidades desses intersticiais na estrutura do Ti.

Made available in DSpace on 2014-12-17T14:08:41Z (GMT). No. of bitstreams: 1 DanielAL_DISSERT.pdf: 4502082 bytes, checksum: bb1da1d41014731b0af8c1e4537a4030 (MD5) Previous issue date: 2009-07-05 / The scale is defined as chemical compounds from inorganic nature, initially soluble in salt solutions, which may precipitate accumulate in columns of production and surface equipment. This work aimd to quantify the crystalline phases of scale through the Rietveld method. The study was conducted in scale derived from columns production wells in development and recipients of pigs. After collecting samples of scale were performed the procedure for separations of inorganic and organic phase and preparation to be analyzed at the X-ray Laboratory. The XRD and XRF techniques were used to monitor whether identifying and quantifying crystalline phases present in the deposits. The SEM technique was used to visualize the morphology of the scales and assess their homogeneity after the milling process. XRD measurements were performed with and without milling and with or without the accessory spinner. For quantify crystalline phases the program DBWStools was used. The procedure for conducting the first refinement was instrumental in setting parameters, then the structural parameters of the phases in the sample and finally the parameters of the function profile used. In the diffraction patterns of samples of scale observed that the best measures were those that passed through the mill and used the accessory spinner. Through the results, it was noted that the quantitative analysis for samples of scale is feasible when need to monitor a particular crystalline phase in a well, pipeline or oil field. Routinely, the quantification of phases by the Rietveld method is hardwork because in many scale was very difficult to identify the crystalline phases present / Incrusta??es s?o precipitados de compostos qu?micos de natureza inorg?nica que podem se acumularem em colunas de produ??o e equipamentos de superf?cie. Este trabalho tem como objetivo quantificar as fases cristalinas de amostras de incrusta??o atrav?s do M?todo Rietveld. O estudo foi realizado em produtos de incrusta??o oriundos de colunas de produ??o de po?os em desenvolvimento e recebedores de pigs. Ap?s a coleta das amostras de incrusta??o, realizou o procedimento de separa??o da fase org?nica da inorg?nica e prepara??o das amostras para an?lise. As t?cnicas de difra??o de raios X e espectrometria por fluoresc?ncia de raios X foram utilizadas para monitorar identificando e quantificando as fases cristalinas presentes nas incrusta??es. A t?cnica de microscopia eletr?nica de varredura foi utilizada para visualizar a morfologia das incrusta??es e avaliar sua homogeneidade ap?s o processo de moagem. Na difra??o de raios X foram realizadas medidas com e sem moagem e com e sem utiliza??o do acess?rio spinner. Para quantifica??o das fases cristalinas utilizou o programa DBWStools 2.25. O procedimento para realiza??o do refinamento consistiu primeiramente em ajustar par?metros instrumentais, em seguida ajustou-se os par?metros estruturais das fases contidas na amostra e por ?ltimo os par?metros da fun??o perfil usada. Nos padr?es de difra??o das amostras de incrusta??o observou-se que os melhores resultados foram os das amostras que passaram pela moagem e que utilizaram o acess?rio spinner. Atrav?s dos resultados obtidos, percebem-se que a an?lise quantitativa para as amostras de incrusta??o ? vi?vel quando se deseja fazer o monitoramento de uma determinada fase cristalina em um po?o, duto ou campo de petr?leo. Rotineiramente, a quantifica??o de fases pelo M?todo Rietveld ? mais trabalhoso visto que em muitas incrusta??es houve grandes dificuldades de identificar as fases cristalinas presentes

Made available in DSpace on 2014-12-17T14:08:34Z (GMT). No. of bitstreams: 1 TiagoRS.pdf: 224853 bytes, checksum: a7ecf3c3cba57ff6b3ea1ac7c4fb7f05 (MD5) Previous issue date: 2009-06-02 / Petr?leo Brasileiro SA - PETROBRAS / Cementation operation consists in an extremely important work for the phases of perforation and completion of oil wells, causing a great impact on the well productivity. Several problems can occur with the cement during the primary cementation, as well as throughout the productive period. The corrective operations are frequent, but they are expensive and demands production time. Besides the direct cost, prejudices from the interruption of oil and gas production till the implementation of a corrective operation must be also taken into account. The purpose of this work is the development of an alternative cement paste constituted of Portland cement and porcelainized stoneware residue produced by ceramic industry in order to achieve characteristics as low permeability, high tenacity, and high mechanical resistance, capable of supporting various operations as production or oil wells recuperation. Four different concentration measures of hydrated paste were evaluated: a reference paste, and three additional ones with ceramic residue in concentrations of the order of 10%, 20% and 30% in relation to cement dough. High resistance and low permeability were found in high concentration of residues, as well as it was proved the pozolanic reactivity of the residue in relation to Portland cement, which was characterized through x-ray and thermogravimetry assays. It was evident the decrease of calcium hydroxide content, once it was substituted by formation of new hydrated products as it was added ceramic residue / A opera??o de cimenta??o consiste em um trabalho de extrema import?ncia para as fases de perfura??o e completa??o de po?os de petr?leo e tem grande impacto sobre a produtividade do po?o. Muitos problemas podem ocorrer com o cimento, tanto durante a cimenta??o prim?ria do po?o como tamb?m durante seu per?odo produtivo. As opera??es para corre??o destes problemas s?o freq?entes, por?m onerosas e demandam tempo de produ??o. Al?m do custo direto da opera??o corretiva, deve m ser ontabilizados, ainda, preju?zos devidos ? interrup??o da produ??o de ?leo e g?s at? que uma opera??o de corre??o seja realizada. Este trabalho tem como objetivo o desenvolvimento de pastas cimentantes alternativas, constitu?das por cimento Portland e um res?duo de porcelanato produzido pela ind?stria cer?mica, a fim de obter caracter?sticas como baixa permeabilidade, alta tenacidade e alta resist?ncia mec?nica, capazes de suportar as diversas opera??es, tanto de produ??o como de recupera??o de po?os de petr?leo. Foram avaliadas quatro concentra??es diferentes de pastas hidratadas: uma pasta de refer?ncia e tr?s pastas contendo res?duo cer?mico nas concentra??es de 10%, 20% e 30%, em rela??o ? massa do cimento. Foram encontradas, para as maiores concentra??es de res?duo, maior resist?ncia mec?nica e menor permeabilidade, al?m de ser comprovada a reatividade pozol?nica do res?duo com o cimento Portland. Esta foi caracterizada atrav?s dos ensaios de Difra??o de Raios X e Termogravimetria, ficando clara a diminui??o do teor de hidr?xido de c?lcio, substitu?do pela forma??o de novos produtos hidratados ? medida que se adicionava o res?duo cer?mico