EXPERIMENTAL STUDY OF TWO-PHASE FLOW IN LARGE-DIAMETER ANNULAR DUCTS
Alex Roger Almeida Colmanetti1; Oscar Mauricio Hernandez Rodriguez1; Marcelo Souza de Castro2; Tor Kindsbekken Kjeldby3; Peter W. J. Derks3
1 EESC-USP; 2 UNICAMP; 3 STATOIL
doi:10.20906/CPS/COB-2015-2710
Resumo
Gas-liquid flows in annular ducts are present in many industrial applications, e.g., in directional oil wells. However, even global characteristics of these flows such as flow patterns or two-phase pressure gradient are so far not fully understood. The common design approach of annular ducts used for transport of gas-liquid mixtures has been based on the hydraulic-diameter concept. The limitations of this method have been leading to significant oversizing. This experimental study aims to evaluate the conditions for which this approach is suitable and present new data on vertical gas-liquid flows in an annular geometry. An experimental setup of 10.5 m length was constructed for this work. The investigation was conducted using air and water as working fluids. Comparable experiments were performed in: (i) a reference pipe setup and (ii) a duct of concentric annular configuration. Identical values of the equivalent hydraulic diameter were applied. Flow pattern, pressure drop and void fraction data were obtained for both configurations. The data will be of large importance for development of new models for flow-pattern transition and closure correlations, which are essential for optimized design of oil wells.
Palavras-chave: two-phase flow; gas-liquid flow; annular duct; hydraulic diameter; flow patterns; pressure gradient