Estudo numérico da aplicação do sistema gerador de nitrogênio para remoção de depósitos de parafina

• Ano de defesa: 2024
• Autor(a) principal: Cavalcante, Rafael Ferreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Engenharia Química; Centro de Ciências Agrárias e Engenharias; UFES; Programa de Pós-Graduação em Engenharia Química
• Palavras-chave em Português: Engenharia química; Equações diferenciais - Soluções numéricas; Indústria offshore de petróleo; Cera de parafina; Exploração de petróleo offshore; Sistema gerador de nitrogênio (SGN); Sistemas Pipe-in-pipe (PIP); Condução de calor não linear; Offshore oil exploration; Nitrogen generation system (SGN); Pipe-in-pipe systems (PIP); Nonlinear heat conduction; Engenharia Química
• Link de acesso: http://repositorio.ufes.br/handle/10/17679

Offshore oil exploration has significant challenges, including the formation of hydrate and paraffin wax deposits, causing billionaire losses to the oil and natural gas industry. The nitrogen generating system (SGN) is a thermal and chemical technique applied to remove these deposits, employing an exothermic chemical reaction that promotes paraffin wax melting. Pipe-in-pipe (PIP) systems with thermal insulation layers are common in this scenario, aiming to optimize the system’s thermal efficiency. This dissertation conducts to a numerical study of an SGN application in a multilayer PIP system with paraffin wax blockage, to investigate the efficiency and feasibility of the technique in removing the deposit without compromising the PIP’s insulation materials. The mathematical formulation yields to a nonlinear transient two dimensional heat conduction model with chemical reaction and phase change. The solution of the transient problem employs the explicit Euler method for time integration, with spatial derivatives computed directly from the temperature nodal values. The results demonstrate that the SGN’s chemical reagents are quickly consumed, generating a high amount of heat, sufficient to remove the paraffin wax deposit. The simulation reaches a liquid fraction of 0.95. The results also show that the temperature of the thermal insulation layers exceeds their ideal working temperature, but remains below their melting point, reaching 140 ◦C in the innermost insulation layer. Additionally, the results indicate that the released heat is strongly dependent on the pH at which the reaction occur