Estudo do escoamento laminar sólido-líquido em anular excêntrico empregando a técnica de dinâmica de fluidos computacional

• Ano de defesa: 2014
• Autor(a) principal: Facuri, Rafael Manache
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Energia; UFES; Programa de Pós-Graduação em Energia
• Palavras-chave em Português: Multiphase flow; Eulerian Granular Model; Hole cleaning; CFD; Limpeza de poço; Fluidodinâmica computacional; Escoamento multifásico; Modelo Euleriano Granular; Engenharia/Tecnologia/Gestão; 620.9
• Link de acesso: http://repositorio.ufes.br/handle/10/5342

Exploration techniques such as horizontal wells to increase production efficiency have been practiced but it brings a challenging scenario for the operation, which includes the transport of cuttings during the drilling operation. Several parameters affect the efficiency of the transport including mainly properties of the drilling fluid and the characteristics of the drilling system. Besides the wide range of variables, and their interactions, which affects this efficiency and makes this study difficult, the real conditions in which these variables are applied as high temperature and pressure, it makes the challenge even more complex, especially because these conditions are not always possible to be reproduced in experimental units. In this sense the multiphase flow phenomenon of carrying cuttings by the drilling fluid was modeled through the technique of CFD (Computational Fluid Dynamics). The computational model was based on the Eulerian Granular approach for simulating the solid-liquid multiphase flow in a laminar regime and the model was validated by the experimental data from Yu et al. (2007). With this model the fluid dynamics of a non-Newtonian fluid Bingham plastic was analyzed in a horizontal column with eccentricity of 13.74 mm (offset) studying the effects of the drilling fluid flow, the drilling pipe rotation and penetration rate in the efficiency of cuttings removal, using central composite design with 16 runs. The comparison of the experimental results of Yu et al. (2007) and the model showed good agreement with average deviations of |6.6%|. That said, it was possible to elucidate the order of magnitude of the effects of the variables on the cutting removal and the pressure drop, giving special attention for the maximizing effect of drilling pipe rotation on the hole cleaning efficiency and for the important effect of fluid flow on the pressure drop. However, the flow had insignificant effect on the cuttings concentration, showing that within the tested range of laminar flow, the hole cleaning efficiency is little affected by flow of the drilling fluid. The results of the numerical simulations agreed with the results found in the literature.