Estudo de emulsões de petróleos brasileiros por ressonância magnética nuclear (RMN) de baixo campo bidimensional

Detalhes bibliográficos
Ano de defesa: 2012
Autor(a) principal: Carneiro, Giovanna da Fraga
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal do Espírito Santo
BR
Mestrado em Química
Centro de Ciências Exatas
UFES
Programa de Pós-Graduação em Química
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
54
Link de acesso: http://repositorio.ufes.br/handle/10/4679
Resumo: Emulsions are a common issuein crude oil exploration, since water is also found in hydrocarbon reservoirs or can be injected in enhanced recovery projects. Although common, emulsions are a problem in oil industry and low-field 1H Nuclear Magnetic Resonance (NMR) can be a powerful tool for studying them. Longitudinal and transverserelaxation times(T1and T2, respectively)and diffusion coefficient (D) are properties measured through low-field NMR that can help inferring many properties of the fluids involved in the oil production.Two-dimensional NMR, specially, has a high potential for emulsion characterization for combining in one experiment, for example, T2and Dinformation. In this study4 oils were analyzedthrough bidimensional NMR techniques, resulting in T1-T2and D-T2plots. Two of the crude oils studied were water free, so emulsions were prepared by the addition ofMnCl2doped water. The other crudes already presentedemulsions. T2distribuition curves allowed the quantification of water in oil in the cases where water and oil presented different T2values, yielding 23% error for one crude oil and an average of 10% for a set of prepared emulsions.For theemulsions preparedin the laboratory, the separation of the phases was recordedby NMR measurements. For some of these prepared emulsions demulsifiers were added and their speed of action could be evaluated. D-T2plots allowed the visualization of different water behaviors–more or less restricted –due to water in oil emulsion, which can be correlated to droplet size distribution. Quantification of water in oil through Ddistribution curves was not possible.