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Previous issue date: 2012-12-14 / One of the major challenges faced nowadays by oil companies is the exploration of pre-salt basins. Thick salt layers were formed in remote ages as a consequence of the evaporation of sea water containing high concentrations of NaCl and KCl. Deep reservoirs can be found below salt formations that prevent the outflow of oil, thus improving the success in oil prospection. The slurries used in the cement operations of salt layers must be adequate to the properties of those specific formations. At the same time, their resulting properties are highly affected by the contamination of salt in the fresh state. It is t herefore important to address the effects of the presence of salt in the cement slurries in order to assure that the well sheath is able to fulfill its main role to provide zonal isolation and mechanical stability. In this scenario, the objective of the present thesis work was to evaluate the effect of the presence of NaCl and KCl premixed with cement and 40% silica flour on the behavior of cement slurries. Their effect in the presence of CO2 was also investigated. The rheological behavior of slurries containing NaCl and KCl was evaluated along with their mechanical strength. Thermal and microstructural tests were also carried out. The results revealed that the presence of NaCl and KCl affected the pozzolanic activity of silica flour, reducing the strength of the hardened slurries containing salt. Friedel?s salt was formed as a result of the bonding between free Cl- and tricalcium aluminate. The presence of CO2 also contributed to the degradation of the slurries as a result of a process of carbonation/bicarbonataion / 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 ? natureza dos sais, pois estes se encontram na natureza com distintas caracter?sticas. Assim, este trabalho teve como objetivo avaliar o comportamento da adi??o de sais NaCl e KCl em sistemas de pastas de cimento contendo 40% de s?lica flour e avaliar o comportamento dessas pastas frente a presen?a de CO2. As propriedades foram avaliadas atrav?s de ensaios de reologia, resist?ncia ? compress?o pelo m?todo ultrass?nico (UCA) e resist?ncia mec?nica pelo m?todo destrutivo, bem como com o uso de t?cnicas de caracteriza??o t?rmica (TG/DTG), difra??o de raios X (DRX), microscopia eletr?nica de varredura (MEV) e an?lise de EDS em microanalisadores de sonda eletr?nica (EPMA). Os resultados mostraram que a presen?a do NaCl e KCl, interferem na atividade pozol?nica da s?lica, reduzindo a resist?ncia das pastas quando adicionado altas concentra??es dos sais. Essa interfer?ncia foi comprovada devido a forma??o do sal de Friedel, resultado da liga??o dos cloretos livres ao aluminato tric?lcico, incorporado ?s fases s?lidas do cimento hidratado. Para o estudo da influ?ncia de meios ricos em CO2 em pastas de cimento, foi observada a degrada??o das pastas atrav?s do processo de carbonata??o seguido da bicarbonata??o, resultando na perda da resist?ncia mec?nica
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/12802 |
| Date | 14 December 2012 |
| Creators | Barbosa, Carina Gabriela de Melo e Melo |
| Contributors | CPF:15724520800, http://lattes.cnpq.br/0022988322449627, Melo, Dulce Maria de Ara?jo, CPF:06117988320, http://lattes.cnpq.br/3318871716111536, Silva, Lucineide Balbino da, CPF:78921147420, http://lattes.cnpq.br/2926581493300295, Anjos, Marcos Alyssandro Soares dos, CPF:02262184496, http://lattes.cnpq.br/3904325866154130, Delmonte, Mauricio Roberto Bomio, CPF:27816279841, http://lattes.cnpq.br/9558299312183852, Martinelli, Ant?nio Eduardo |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncia e Engenharia de Materiais, UFRN, BR, Processamento de Materiais a partir do P?; Pol?meros e Comp?sitos; Processamento de Materiais a part |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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