Slug Dynamics in Gas-Liquid Pipe Flow

2000 ◽  
Vol 122 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Hong-Quan Zhang ◽  
Subash S. Jayawardena ◽  
Clifford L. Redus ◽  
James P. Brill
Keyword(s):  
Pressure Gradient ◽  
Flow Pattern ◽  
Pipe Flow ◽  
Film Flow ◽  
Control Volume ◽  
Experimental Results ◽  
Liquid Holdup ◽  
Flow Pattern Transition ◽  
Slug Flows

The continuity and momentum equations for fully developed and spatially developing slug flows are established by considering the entire film zone as the control volume. They are used for the calculations of pressure gradient, slug frequency, liquid holdup in the film, flow pattern transition, slug dissipation, and slug tracking. Comparison with available experimental results shows that these equations correctly describe the slug dynamics in gas-liquid pipe flow. [S0195-0738(00)00701-9]

Unified Model for Gas-Liquid Pipe Flow Via Slug Dynamics: Part 1 — Model Development

2002 ◽  
Author(s):  
Hong-Quan Zhang ◽  
Qian Wang ◽  
Cem Sarica ◽  
James P. Brill
Keyword(s):  
Flow Pattern ◽  
Pipe Flow ◽  
Slug Flow ◽  
Control Volume ◽  
Model Development ◽  
Flow Patterns ◽  
Hydrodynamic Characteristics ◽  
Momentum Exchange ◽  
Two Phase ◽  
Inclination Angles

A unified hydrodynamic model is developed for predictions of flow pattern transitions, pressure gradient, liquid holdup and slug characteristics in gas-liquid pipe flow at different inclination angles from −90 to 90 deg. The model is based on the dynamics of slug flow, which shares transition boundaries with all the other flow patterns. By use of the entire film zone as the control volume, the momentum exchange between the slug body and the film zone is introduced into the momentum equations for slug flow. The equations of slug flow are used not only to calculate the slug characteristics, but also to predict transitions from slug flow to other flow patterns. Significant effort has been made to eliminate discontinuities among the closure relationships through careful selection and generalization. The flow pattern classification is also simplified according to the hydrodynamic characteristics of two-phase flow.

Pressure Effects on Low-Liquid-Loading Oil/Gas Flow in Slightly Upward Inclined Pipes: Flow Pattern, Pressure Gradient, and Liquid Holdup

SPE Journal ◽  
2019 ◽  
Vol 24 (05) ◽  
pp. 2221-2238 ◽  
Author(s):  
Hendy T. Rodrigues ◽  
Eduardo Pereyra ◽  
Cem Sarica
Keyword(s):  
Pressure Gradient ◽  
Flow Pattern ◽  
Slug Flow ◽  
Annular Flow ◽  
Flow Patterns ◽  
Pressure Effects ◽  
Liquid Holdup ◽  
Liquid Loading ◽  
Interfacial Roughness ◽  
Oil Gas

Summary This paper studied the effects of system pressure on oil/gas low–liquid–loading flow in a slightly upward inclined pipe configuration using new experimental data acquired in a high–pressure flow loop. Flow rates are representative of the flow in wet–gas transport pipelines. Results for flow pattern observations, pressure gradient, liquid holdup, and interfacial–roughness measurements were calculated and compared to available predictive models. The experiments were carried out at three system pressures (1.48, 2.17, and 2.86 MPa) in a 0.155–m–inside diameter (ID) pipe inclined at 2° from the horizontal. Isopar™ L oil and nitrogen gas were the working fluids. Liquid superficial velocities ranged from 0.01 to 0.05 m/s, while gas superficial velocities ranged from 1.5 to 16 m/s. Measurements included pressure gradient and liquid holdup. Flow visualization and wire–mesh–sensor (WMS) data were used to identify the flow patterns. Interfacial roughness was obtained from the WMS data. Three flow patterns were observed: pseudo-slug, stratified, and annular. Pseudo-slug is characterized as an intermittent flow where the liquid does not occupy the whole pipe cross section as does a traditional slug flow. In the annular flow pattern, the bulk of the liquid was observed to flow at the pipe bottom in a stratified configuration; however, a thin liquid film covered the whole pipe circumference. In both stratified and annular flow patterns, the interface between the gas core and the bottom liquid film presented a flat shape. The superficial gas Froude number, FrSg, was found to be an important dimensionless parameter to scale the pressure effects on the measured parameters. In the pseudo-slug flow pattern, the flow is gravity–dominated. Pressure gradient is a function of FrSg and liquid superficial velocity, vSL. Liquid holdup is independent of vSL and a function of FrSg. In the stratified and annular flow patterns, the flow is friction–dominated. Both pressure gradient and liquid holdup are functions of FrSg and vSL. Interfacial–roughness measurements showed a small variation in the stratified and annular flow patterns. Model comparison produced mixed results, depending on the specific flow conditions. A relation between the measured interfacial roughness and the interfacial friction factor was proposed, and the results agreed with the existing measurements.

scholarly journals Engineering Simulation Tests on Multiphase Flow in Middle- and High-Yield Slanted Well Bores

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2591 ◽  
Author(s):  
Dan Qi ◽  
Honglan Zou ◽  
Yunhong Ding ◽  
Wei Luo ◽  
Junzheng Yang
Keyword(s):  
Multiphase Flow ◽  
Prediction Model ◽  
Flow Pattern ◽  
Pipe Flow ◽  
Slug Flow ◽  
High Yield ◽  
Transition Flow ◽  
Liquid Holdup ◽  
Flow Pattern Map ◽  
Flow Pressure

Previous multiphase pipe flow tests have mainly been conducted in horizontal and vertical pipes, with few tests conducted on multiphase pipe flow under different inclined angles. In this study, in light of mid–high yield and highly deviated wells in the Middle East and on the basis of existent multiphase flow pressure research on well bores, multiphase pipe flow tests were conducted under different inclined angles, liquid rates, and gas rates. A pressure prediction model based on Mukherjee model, but with new coefficients and higher accuracy for well bores in the study block, was obtained. It was verified that the newly built pressure drawdown prediction model tallies better with experimental data, with an error of only 11.3%. The effect of inclination, output, and gas rate on the flow pattern, liquid holdup, and friction in the course of multiphase flow were analyzed comprehensively, and six kinds of classical flow regime maps were verified with this model. The results showed that for annular and slug flow, the Mukherjee flow pattern map had a higher accuracy of 100% and 80–100%, respectively. For transition flow, Duns and Ros flow pattern map had a higher accuracy of 46–66%.

Unified Model for Gas-Liquid Pipe Flow via Slug Dynamics—Part 1: Model Development

2003 ◽  
Vol 125 (4) ◽  
pp. 266-273 ◽  
Author(s):  
Hong-Quan Zhang ◽  
Qian Wang ◽  
Cem Sarica ◽  
James P. Brill
Keyword(s):  
Flow Pattern ◽  
Pipe Flow ◽  
Slug Flow ◽  
Control Volume ◽  
Model Development ◽  
Flow Patterns ◽  
Hydrodynamic Characteristics ◽  
Momentum Exchange ◽  
Two Phase ◽  
Inclination Angles

A unified hydrodynamic model is developed for predictions of flow pattern transitions, pressure gradient, liquid holdup and slug characteristics in gas-liquid pipe flow at all inclination angles from −90° to 90° from horizontal. The model is based on the dynamics of slug flow, which shares transition boundaries with all the other flow patterns. By use of the entire film zone as the control volume, the momentum exchange between the slug body and the film zone is introduced into the momentum equations for slug flow. The equations of slug flow are used not only to calculate the slug characteristics, but also to predict transitions from slug flow to other flow patterns. Significant effort has been made to eliminate discontinuities among the closure relationships through careful selection and generalization. The flow pattern classification is also simplified according to the hydrodynamic characteristics of two-phase flow.

Frictional Pressure Drops of Two-Phase R-134A Flow in Horizontal and Vertical U-Type Wavy and Straight Tubes

2006 ◽  
Author(s):  
Ing Youn Chen ◽  
Yu-Shi Wu ◽  
Yu-Juei Chang ◽  
Chi-Chuan Wang
Keyword(s):  
Pressure Gradient ◽  
Flow Pattern ◽  
Straight Tube ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Pattern Transition ◽  
The Difference ◽  
R 134A ◽  
Gradient Ratio ◽  
Phase Pressure

This study presents the measurements of R-134a two-phase frictional pressure gradient subject to vertical and horizontal arrangements of a U-type wavy tube with inner diameter of 5.07 mm and a curvature ratio of 5. The ratio between two-phase pressure gradients of U-bend and straight tube is about 2.5 - 3.5. For the straight tube, the frictional two-phase pressure gradient ratio between the vertical and horizontal arrangements is marginally higher (1.0 - 1.2) for annular flow pattern at x > 0.5, and is 1.0 - 1.4 for the U-bend in the wavy tube. The higher resistance in the vertical arrangement is due to the buoyancy force against the flow inertia. However, for x < 0.5, this ratio is gradually increased due to the difference of flow pattern. The ratio is increased to 1.8 in the straight tube. For the U-bend, the ratio is 2.1 for flow entering the upper tube and is 1.5 for flow entering the lower tube at x = 0.1 and G = 200 kg/m2·s. For the vertical wavy tube, additional effects like the flow pattern transition, liquid flow reversal, and freezing slug may cause additional pressure drops.

A Model for Wetted-Wall Fraction and Gravity Center of Liquid Film in Gas/Liquid Pipe Flow

SPE Journal ◽  
2011 ◽  
Vol 16 (03) ◽  
pp. 692-697 ◽  
Author(s):  
Hong-Quan Zhang ◽  
Cem Sarica
Keyword(s):  
Liquid Film ◽  
Flow Pattern ◽  
Pipe Flow ◽  
Present Model ◽  
Stratified Flow ◽  
Gravity Center ◽  
Transition Prediction ◽  
Flow Pattern Transition ◽  
Circle Model ◽  
Geometrical Relationship

Summary The model presented in this study unifies the predictions of liquid wetted-wall fraction, film gravity center, and flow-pattern transition between stratified and annular flows. It is based on the instability of the liquid film in an equilibrium stratified flow proposed by Taitel and Dukler (1976) for flow-pattern transition prediction from stratified flow to nonstratified flows. The geometrical relationship between the wetted-wall fraction and the gravity center of the liquid film is established based on the double-circle model proposed by Chen et al. (1997), and is further simplified with explicit approximation. The predictions of the present model are compared and agree well with experimental wetted-wall-fraction measurements and flow-pattern observations from different authors.

Effects of Density and Viscosity in Vertical Zero Net Liquid Flow

2000 ◽  
Vol 122 (2) ◽  
pp. 49-55 ◽  
Author(s):  
Hyoung-Jin An ◽  
Julius P. Langlinais ◽  
S. L. Scott
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Petroleum Industry ◽  
Flow Distribution ◽  
Liquid Holdup ◽  
Cylindrical Cyclone ◽  
Flow Pattern Transition ◽  
Transition Criteria ◽  
Superficial Gas Velocity ◽  
Effects Of Density

An experimental study was conducted to investigate the effects of density and viscosity on zero net liquid flow (ZNLF) in vertical pipes. Predicting liquid holdup under ZNLF conditions is necessary in several types of petroleum industry operations. These include predicting bottomhole pressures in pumping oil wells and the design of compact gas-liquid cylindrical cyclone (GLCC©)1 separators. Models are proposed to predict flow pattern transitions under ZNLF conditions and comparisons are made with commonly used vertical flow pattern transition criteria. Data was collected using a 3-in.-diam, 14-ft-section of transparent vertical pipe. Several different fluids, of differing density and viscosity, were utilized with air flowing at approximately 25 psig. Results are presented showing the liquid holdup and the flow distribution coefficient C0 as a function of density, viscosity, and superficial gas velocity. [S0195-0738(00)00402-7]

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