Upward Vertical Two-Phase Flow Through an Annulus—Part I: Single-Phase Friction Factor, Taylor Bubble Rise Velocity, and Flow Pattern Prediction

Abstract

Upward gas-liquid flow through vertical concentric and fully eccentric annuli was studied both experimentally and theoretically. A flow system was designed and constructed for this study. The system consists of a 16-m long vertical annulus with 76.2-mm i.d. casing and 42.2-mm o.d. tubing. A comprehensive experimental investigation was conducted for both concentric and fully eccentric annuli configurations, using air-water and air-kerosene mixtures as the flowing fluids. Included were definition and classification of the existing flow patterns and development of flow pattern maps. Measurements of volumetric average liquid holdup and average total pressure gradient were made for each flow pattern for a wide range of flow conditions. Additional data include single-phase friction factor values and Taylor bubble rise velocities in a stagnant liquid column. Data analysis revealed that application of the hydraulic diameter concept for annuli configurations is not always adequate, especially at low Reynolds number flow conditions. A more rigorous approach was thus required for accurate prediction of the flow behavior, especially for two-phase flow. Part I of the study includes experimental data and analyses of single-phase friction factor, Taylor bubble rise velocity, and flow pattern transition boundaries.

Upward Gas-Liquid Flow in Concentric and Eccentric Annular Spaces

“…In relation to the present case study, the two-phase flow patterns for concentric and fully eccentric annulus configurations are shown in Figure 3 taken from Caetano et al (1992). According to this study, the flow regimes in the annulus can be described as follows:…”

“…Even fewer works have tried to establish mechanistic models to predict flow pattern transitions: Caetano et al (1992) and Lage and Time (2000) modified the model from Taitel et al (1980) for open pipes to predict flow patterns in an annular space. Das et al (2002) modified the previous models to account for asymmetric flow regimes seen in annular spaces.…”

“…Das et al (2002) modified the previous models to account for asymmetric flow regimes seen in annular spaces. (Caetano et al, 1992).…”

Estudo experimental, simulação numérica e modelagem fenomenológica da separação gravitacional de gás no fundo de poços direcionais

“…--São Carlos, 2012. Figura 4.2 -Padrão de escoamento bolhas dispersas em um duto anular, Caetano et al (1992a). .... 81…”

Modelo de mistura aplicado para a previsão de Holdup e gradiente de pressão bifásico em duto anular de grande diâmetro

“…Figura 2-5: Padrões de escoamento em um duto anular, para um escoamento vertical ascendente [Caetano et al (1992) …”