Effect of Inclination Pipe Angle on Oil-Water Two Phase Flow Patterns and Pressure Loss

Author(s):  
S. Alireza Hojati ◽  
Pedram Hanafizadeh

The flow patterns in two phase and multi-phase flows is a significant factor which influences many other parameters such as drag force, drag coefficient and pressure drop in pipe lines. One of the major streams in the gas and oil industries is oil-water two phase flow. The main flow patterns in oil-water flows are bubbly, slug, dual continuous, stratified and annular. In the present work flow patterns in two phase oil-water flow were investigated in a 0.5in diameter pipe with length of 2m. 3D simulation was used for this pipe and six types of mesh grid were used to investigate mesh independency of the simulation. The proposed numerical analyses were performed by a CFD package which is based both on volume of fluid (VOF) and Eulerian-Eulerian methods. The results showed that some flow patterns can be simulated better with VOF method and some other maybe in Eulerian-Eulerian method, so these two methods were compared with together for all flow patterns. The flow patterns may be a function of many parameters in flow. One of the important parameter which may affect flow patterns in pipe line is pipe inclination angle; therefore flow patterns in the different pipe inclination angles were investigated in two phase oil-water flow. The range of inclinations has been varied between −45 to +45 degree about the horizon. In the presented simulation oil is mixed with water via a circular hole at center of the pipe, the ratio of oil surface to water surface at entrance is 2/3 so water phase was considered as the main phase. Flow patterns were investigated for every angle of pipe and numerical results were compared with available experimental data for verification. Also the flow patterns simulated by numerical approaches were compared with available flow regime maps in the previous literatures. Finally, effect of pipe inclination angle and flow patterns on the pressure loss were investigated comprehensively.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Wang ◽  
Wei Cheng ◽  
Kai Li ◽  
Chen Lou ◽  
Jing Gong

A systematic work on the prediction of flow patterns transition of the oil-water two-phase flows is carried out under a wide range of oil phase viscosities, where four main flow regimes are considered including stratified, dispersed, core-annular, and intermittent flow. For oil with a relatively low viscosity, VKH criterion is considered for the stability of stratified flow, and critical drop size model is distinguished for the transition of o/w and w/o dispersed flow. For oil with a high viscousity, boundaries of core-annular flow are based on criteria proposed by Bannwart and Strazza et al. and neutral stability law ignoring that the velocity of the viscous phase is introduced for stratified flow. Comparisons between predictions and quantities of available data in both low and high viscosity oil-water flow from literatures show a good agreement. The framework provides extensive information about flow patterns transition of oil-water two-phase flow for industrial application.


2019 ◽  
Vol 13 (1) ◽  
pp. 51-56
Author(s):  
Grzegorz Górski ◽  
Grzegorz Litak ◽  
Romuald Mosdorf ◽  
Andrzej Rysak

Abstract By changing the air and water flow relative rates in the two-phase (air-water) flow through a minichannel, we observe aggregation and partitioning of air bubbles and slugs of different sizes. An air bubble arrangement, which show non-periodic and periodic patterns. The spatiotemporal behaviour was recorded by a digital camera. Multiscale entropy analysis is a method of measuring the time series complexity. The main aim of the paper was testing the possibility of implementation of multiscale entropy for two-phase flow patterns classification. For better understanding, the dynamics of the two-phase flow patterns inside the minichannel histograms and wavelet methods were also used. In particular, we found a clear distinction between bubbles and slugs formations in terms of multiscale entropy. On the other hand, the intermediate region was effected by appearance of both forms in non-periodic and periodic sequences. The preliminary results were confirmed by using histograms and wavelets.


1998 ◽  
Vol 120 (1) ◽  
pp. 8-14 ◽  
Author(s):  
J. G. Flores ◽  
C. Sarica ◽  
T. X. Chen ◽  
J. P. Brill

Two-phase flow of oil and water is commonly observed in wellbores, and its behavior under a wide range of flow conditions and inclination angles constitutes a relevant unresolved issue for the petroleum industry. Among the most significant applications of oil-water flow in wellbores are production optimization, production string selection, production logging interpretation, down-hole metering, and artificial lift design and modeling. In this study, oil-water flow in vertical and inclined pipes has been investigated theoretically and experimentally. The data are acquired in a transparent test section (0.0508 m i.d., 15.3 m long) using a mineral oil and water (ρo/ρw = 0.85, μo/μw = 20.0 & σo−w = 33.5 dyne/cm at 32.22°C). The tests covered inclination angles of 90, 75, 60, and 45 deg from horizontal. The holdup and pressure drop behaviors are strongly affected by oil-water flow patterns and inclination angle. Oil-water flows have been grouped into two major categories based on the status of the continuous phase, including water-dominated and oil-dominated flow patterns. Water-dominated flow patterns generally showed significant slippage, but relatively low frictional pressure gradients. In contrast, oil-dominated flow patterns showed negligible slippage, but significantly large frictional pressure gradients. A new mechanistic model is proposed to predict the water holdup in vertical wellbores based on a drift-flux approach. The drift flux model was found to be adequate to calculate the holdup for high slippage flow patterns. New closure relationships for the two-phase friction factor for oil-dominated and water-dominated flow patterns are also proposed.


Measurement ◽  
2016 ◽  
Vol 93 ◽  
pp. 503-514 ◽  
Author(s):  
W.X. Liu ◽  
N.D. Jin ◽  
Y.F. Han ◽  
L.S. Zhai ◽  
X. Chen ◽  
...  

2009 ◽  
Vol 58 (11) ◽  
pp. 7544
Author(s):  
Zong Yan-Bo ◽  
Jin Ning-De ◽  
Wang Zhen-Ya ◽  
Wang Zhen-Hua

2020 ◽  
Vol 185 ◽  
pp. 01091
Author(s):  
Dongxu Liu ◽  
Na Huang ◽  
Lei Liu

To investigate the resistance performance of pore throats in porous media, a new method was used to conduct experiments to indirectly measure the local pressure loss of single-phase water and oil- water two-phase flow through pore-throat structures. Four microchannels were designed and manufactured with MEMS technology. One of the four microchannels is a straight duct with no throat and each of the other three has one throat within the passage. By comparison of total pressure drops between the straight duct with no throat and the channel with a throat at the same flow rate, the local pressure loss over a pore- throat structure can be determined. In this paper, the pore-throat structure is defined as a combination of a contraction, an expansion and a throat to stimulate the pore throat in porous media. Experimental results show that local pressure loss, nonlinear with the flow rate, grows up with the decrease of throat size and the increase of oil volume fraction. Local loss coefficient, characterizing the local resistance performance of pore-throat structure, diminishes with the increase of Reynolds number. Reynolds number (in throat part) is in the range of 100-1100. A new empirical correlation of local loss coefficient is proposed for single-phase water and oil-water two-phase flow through pore-throat structure.


2021 ◽  
Author(s):  
Zurwa Khan ◽  
Reza Tafreshi ◽  
MD Ferdous Wahid ◽  
Albertus Retnanto

Abstract Mechanistic models are necessary for understanding and predicting the behavior of liquid-liquid flow for multiple pipe dimensions, mixture properties, and flow patterns. In this paper, a mechanistic model is proposed to calculate pressure drop across circular channels for liquid-liquid two-phase flow. The developed model considers several key aspects of liquid-liquid flow, such as mixed and wavy liquid-liquid interfaces and dispersion within each liquid’s layers. Unique identifiers, such as height, turbulence, and dispersion, are calculated for each phase, using an augmented separated flow model and nonlinear optimization. Comparison of the proposed model with experimental data, comprising of multiple inclination angles and flow patterns, shows accurate predictions for a variety of liquid-liquid flow patterns, including double- and triple-layered flow.


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