scholarly journals A Unified Model of Oil/Water Two-Phase Flow through the Complex Pipeline

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qingchun Gao ◽  
Zhiming Wang ◽  
Quanshu Zeng

Oil-water two-phase flow through the complex pipeline, consisting of varying pipes and fittings in series or parallel, is commonly encountered in the petroleum industry. However, the majority of the current study is mainly limited to single constant-radius pipe. In this paper, a unified model of oil-water two-phase flow in the complex pipeline is developed based on the combination of pipe serial-parallel theory, flow pattern transformation criterion, two-fluid model, and homogenous model. A case is present to verify the unified model and compare with CFD results. The results show that the proposed unified model can achieve excellent performance in predicting both the flow distributions and pressure drops of oil-water two-phase flow in the complex pipeline. Compared with CFD results for water volumetric fractions ranging from 0% to 100%, the highest absolute percentage error of the proposed model is 14.4% and the average is 9.8%.

2012 ◽  
Vol 29 (2) ◽  
pp. 115 ◽  
Author(s):  
N.Z Aung ◽  
T Yuwono

Nine existing mixture viscosity models were tested for predicting a two-phase pressure drop for oil-water flow and refrigerant (R.134a) flow. The predicted data calculated by using these mixture viscosity models were compared with experimental data. Predicted data from using one group of mixture viscosity models had a good agreement with the experimental data for oil-water two-phase flow. Another group of viscosity models was preferable for gas-liquid flow, but these models gave underestimated values with an error of about 50%. A new and more reliable mixture viscosity model was proposed for use in the prediction of pressure drop in gas-liquid two-phase flow.


Author(s):  
Mehaboob Basha ◽  
S. M. Shaahid ◽  
M. Mudasar Imam ◽  
Aftab Ahmad ◽  
Luai M. Al-Hadhrami

Air-water two-phase flow in a pipeline often occurs in petroleum industry. It is important to study behavior of such flows in order to characterize two-phase flow in upstream production pipelines. This paper presents pressure drop measurements of air-water two-phase flow in a horizontal and inclined 4 inch diameter stainless steel pipe at different flow conditions. Experiments were carried out for different inclination angles including; 0°, 15°, 30° (upward and downward flows) and for different water-to-air volume fractions. Inlet superficial water velocities were varied from 0.3 to 3 m/s and reference pressure was set at 1 and 2 bars. For a given superficial air velocity, pressure drop has been found to increase with increase in superficial water velocity. Pressure drop was also affected by the inclination of pipe. Upward flows were associated with high pressure drops as compared to downward flows. Measured pressure drops were compared with existing empirical relations and good agreement was found.


2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Manmatha K. Roul ◽  
Sukanta K. Dash

Two-phase flow pressure drops through thin and thick orifices have been numerically investigated with air–water flows in horizontal pipes. Two-phase computational fluid dynamics (CFD) calculations, using the Eulerian–Eulerian model have been employed to calculate the pressure drop through orifices. The operating conditions cover the gas and liquid superficial velocity ranges Vsg = 0.3–4 m/s and Vsl = 0.6–2 m/s, respectively. The local pressure drops have been obtained by means of extrapolation from the computed upstream and downstream linearized pressure profiles to the orifice section. Simulations for the single-phase flow of water have been carried out for local liquid Reynolds number (Re based on orifice diameter) ranging from 3 × 104 to 2 × 105 to obtain the discharge coefficient and the two-phase local multiplier, which when multiplied with the pressure drop of water (for same mass flow of water and two phase mixture) will reproduce the pressure drop for two phase flow through the orifice. The effect of orifice geometry on two-phase pressure losses has been considered by selecting two pipes of 60 mm and 40 mm inner diameter and eight different orifice plates (for each pipe) with two area ratios (σ = 0.73 and σ = 0.54) and four different thicknesses (s/d = 0.025–0.59). The results obtained from numerical simulations are validated against experimental data from the literature and are found to be in good agreement.


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.


2002 ◽  
Vol 124 (4) ◽  
pp. 239-245 ◽  
Author(s):  
Antonio Rojas-Figueroa ◽  
Yuri V. Fairuzov

The transport of corrosion inhibitors in a pipeline carrying crude oil-water mixture has been studied using a transient liquid-liquid two-phase flow model. The fluid flow model (the hydrodynamic model) is based on a two-fluid model of two-phase flow. The model allows simulating the transfer of inhibitor from one phase to another (inhibitor partitioning) under steady-state and transient oil-water flow conditions. Both stratified and dispersed flow patterns can be modeled. Numerical simulations are presented to demonstrate the effects of topography of the line, locations of the inhibitor injection point, flow pattern, and partitioning of the inhibitor between the phases on the distribution of inhibitor concentration along the pipeline. The modeling can be used to predict the inhibitor volume needed to be injected (the dose rate) in order to provide the required inhibitor concentration in critical sections of crude-oil pipelines.


Author(s):  
Antonio Rojas-Figueroa ◽  
Yuri V. Fairuzov

Abstract The transport of corrosion inhibitors in a pipeline carrying crude oil-water mixture has been studied using a transient liquid-liquid two-phase flow model. The fluid flow model (the hydrodynamic model) is based on a two-fluid model of two-phase flow. The model allows simulating the transfer of inhibitor from one phase to another (inhibitor partitioning) under steady state and transient oil-water flow conditions. Both stratified and dispersed flow patterns can be modeled. Numerical simulations are presented to demonstrate the effects of topography of the line, locations of the inhibitor injection point, flow pattern, and partitioning of the inhibitor between the phases on the distribution of inhibitor concentration along the pipeline. The modeling can be used to predict the inhibitor volume needed to be injected (the dose rate) in order to provide the required inhibitor concentration in critical sections of crude-oil pipelines.


Author(s):  
Puya Javidmand ◽  
Klaus A. Hoffmann

Small-diameter tubes are utilized widely as expansion devices in refrigeration systems. They are employed in either kinds of short-tube orifices or long capillary tubes. Performance of these tubes is reliant upon critical flashing of the two-phase flow that controls the mass flow rate of the refrigeration system resulting in a steep reduction in pressure and temperature. The critical flow condition is approached whenever the mass flow rate increases to an amount whereby the choked-flow phenomenon occurs at the outlet of the tube. Due to their very small tube diameter, the evaporating two-phase flow, and the choked-flow condition, numerical analysis of flow through short-tube orifices is challenging. Accordingly, all available numerical analyses of such flows are performed as one-dimensional and in the majority of them, auxiliary correlations are applied to simplify the solution procedure. Typical approaches include homogeneous flow models and separated flow models, both of which consider the two-phase region in thermal equilibrium. The most comprehensive method for analyzing such flows is the two-fluid model in which there is no assumption of equilibrium between phases. Because of the complicated nature of this model, it has been used in a very limited number of previous investigations. Furthermore, two-phase flow calculations at the entrance and vena contracta region were eliminated. In the current investigation, additional steps utilized to improve the accuracy of computations include the following: (1) applying the most comprehensive two-fluid model including the effect of various two-phase flow patterns and the metastability of liquid phase, and (2) performing a two-phase analysis of the evaporating flow through the entrance and vena contracta regions which involves simulating the region as a converging diverging tube and performing a quasi-one-dimensional solution of governing equations through this region. Results showed more compatibility with experimental data in comparison with those of previous investigations for predicting the critical flow condition of common refrigerants HFC-134a and HFC-410a through short-tube orifices and long capillary tubes.


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