Análise do overreading dos sistemas de medição de vazão de gás natural úmido com placa de orifício

• Ano de defesa: 2022
• Autor(a) principal: Aguiar, Pedro Henrique Vidal
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Energia; Centro Universitário Norte do Espírito Santo; UFES; Programa de Pós-Graduação em Energia
• Palavras-chave em Português: Ponto de orvalho; Gás úmido; Overreading; Placa de orifício; Medição de vazão; Murdock (1962); Chisholm (1977); Lin (1982); Separated Flow Model (1982); subject.br-rjbn; Engenharia/Tecnologia/Gestão
• Link de acesso: http://repositorio.ufes.br/handle/10/16374

In the Exploration and Production stage of the oil industry, the natural gas flow measurement systems must operate with a temperature higher than the dew point temperature or, otherwise, the natural gas will condense inside the gas pipelines and, in addition to causing increased corrosion and wear in piping and equipment, it can cause the flow measurement to be oversized. This phenomenon of overreading has a direct impact on the total gas production and, consequently, on the distribution of royalties. The most employed equations to estimate overreading use the LockhartMartinelli parameter. However, for real-time monitoring, the use of this parameter becomes complex, as it requires knowledge of the mass flows of liquid and gas and their respective relative densities, and such parameters are difficult to determine when they occur together with the gas and for small amounts of liquid. Thus, the objective of the present work is to analyze orifice plate-type measurement systems flowing wet natural gas through the correlations of Murdock (1962), Chisholm (1977), Lin (1982) and Separated Flow Model (1982) and in the development of overreading equations based on the pressure and temperature of the measurement system. For this, real data of pressure, temperature, molar composition of ten measuring systems of natural gas were simulated in the software DWSIM® 8.0.4 – Chemical Process Simulator for construction of the dew curves and definition of properties of the gas and liquid fractions and later analyzed in SigmaPlot® 14.5 software, used to determine surface and contour plots, as well as overreading equations as a function of pressure and temperature. The results obtained show that the four correlations chosen in this work increase linearly with the increment of the Lockhart-Martinelli parameter and the liquid volume fraction and decrease linearly with the decrement of the quality and gas volume fraction and that the overreading increases with the reduction of the temperature and with the increase of the pressure, being the Chisholm's model (1977) which presents the highest values and the Separated Flow Model (1982) the lowest values of overreading.