Handling of Liquid Holdup in Duyong Two-Phase Flow Pipeline System

1988 ◽  
Author(s):  
M.R. Saad ◽  
B. Singh
Measurement ◽  
2014 ◽  
Vol 49 ◽  
pp. 153-163 ◽  
Author(s):  
Zhao An ◽  
Jin Ningde ◽  
Zhai Lusheng ◽  
Gao Zhongke

2021 ◽  
pp. 1-13
Author(s):  
Ghassan H. Abdul-Majeed ◽  
Abderraouf Arabi ◽  
Gabriel Soto-Cortes

Summary Most of the existing slug (SL) to churn (CH) or SL to pseudo-slug (PS) transition models (empirical and mechanistic) account for the effect of the SL liquid holdup (HLS). For simplicity, some of these models assume a constant value of HLS in SL/CH and SL/PS flow transitions, leading to a straightforward solution. Other models correlate HLS with different flow variables, resulting in an iterative solution for predicting these transitions. Using an experimental database collected from the open literature, two empirical correlations for prediction HLS at the SL/PS and SL/CH transitions (HLST) are proposed in this study. This database is composed of 1,029 data points collected in vertical, inclined, and horizontal configurations. The first correlation is developed for medium to high liquid viscosity two-phase flow (μL > 0.01 Pa·s), whereas the second one is developed for low liquid viscosity flow (μL ≤ 0.01 Pa·s). Both correlations are shown to be a function of superficial liquid velocity (VSL), liquid viscosity (μL), and pipe inclination angle (θ). The proposed correlations in a combination with the HLS model of Abdul-Majeed and Al-Mashat (2019) have been used to predict SL/PS and SL/CH transitions, and very satisfactory results were obtained. Furthermore, the SL/CH model of Brauner and Barnea (1986) is modified by using the proposed HLST correlations, instead of using a constant value. The modification results in a significant improvement in the prediction of SL/CH and SL/PS transitions and fixes the incorrect decrease of superficial gas velocity (VSG) with increasing VSL. The modified model follows the expected increase of VSG for high VSL, shown by the published observations. The proposed combinations are compared with the existing transition models and show superior performance among all models when tested against 357 measured data from independent studies.


1983 ◽  
Vol 35 (05) ◽  
pp. 1003-1008 ◽  
Author(s):  
Hemanta Mukherjee ◽  
James P. Brill

Author(s):  
Ahmad Fazeli ◽  
Ali Vatani

Two-phase flow pipelines are utilized in simultaneous transferring of liquid and gas from reservoir fields to production units and refineries. In order to obtain the hydraulic design of pipelines, pressure drop and liquid holdup were calculated following pipeline flow regime determination. Two semi-empirical and mechanistical models were used. Empirical models e.g. Beggs & Brill, 1973, are only applicable in certain situations were pipeline conditions are adaptable to the model; therefore we used the Taitel & Dukler, 1976, Baker et al., 1988, Petalas & Aziz, 1998, and Gomez et al., 1999, mechanistical models which are practical in more extensive conditions. The FLOPAT code was designed and utilized which is capable of the determining the physical properties of the fluid by either compositional or non-compositional (black oil) fluid models. It was challenged in various pipeline positions e. g. horizontal, vertical and inclined. Specification of the flow regime and also pressure drop and liquid holdup could precisely be calculated by mechanistical models. The flow regimes considered in the pipeline were: stratified, wavy & annular (Segregated Flow), plug & slug (Intermittent Flow) and bubble & mist (Distributive Flow). We also compared output results against the Stanford Multiphase Flow Database which were used by Petalas & Aziz, 1998, and the effect of the flow rate, pipeline diameter, inclination, temperature and pressure on the flow regime, liquid holdup and pressure drop were studied. The outputs (flow regime, pressure drop and liquid holdup) were comparable with the existing pipeline data. Moreover, by this comparison one may possibly suggest the more suitable model for usage in a certain pipeline.


Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 51 ◽  
Author(s):  
Zeyad Almutairi ◽  
Fayez M. Al-Alweet ◽  
Yusif A. Alghamdi ◽  
Omar A. Almisned ◽  
Othman Y. Alothman

Experiments of gas–liquid flow in a circular pipe for horizontal and inclined positions (upward/downward) are reported. The characteristics of two-phase flow in terms of liquid holdup (ε(L)) and induced flow patterns are studied using three experimental techniques; time-averaged ε(L) from permittivity profiles using electrical capacitance tomography (ECT), instantaneous ε(L) using two fast-closing valves (TFCV), and high-speed camera images (HSCI) to capture/identify the formed flow patterns. Thus, this experimental setup enables the development of more well-defined flow patterns in gas–liquid two-phase flow and allows for multi-technique verification of the results. Taken from experimental measurements, a model is proposed to predict ε(L) for high and low situations. The correlations are a function of the hydrodynamic dimensionless quantities which provide hydrodynamic similarity. Regarding different pipe orientations, ε(L) predictions are comparable to ε(L) from experimental measurements with accepted accuracy: 88% of the predictions are within ±5–15% and 98% are below ±20%. The correlations also were validated by reported results and against correlations available in the literature and show higher prediction accuracy. It is confirmed that the kinematic similarity which is achieved by the gas–liquid velocity ratios and the inertial forces influence the flow pattern and the liquid holdup.


Author(s):  
Catalina Posada ◽  
Paulo Waltrich

The present investigation presents a comparative study between two-phase flow models and experimental data. Experimental data was obtained using a 42 m long, 0.05 m ID tube system. The experimental data include conditions for pressures ranging from 1.2 to 2.8 bara, superficial liquid velocities 0.02–0.3 m/s, and superficial gas velocity ranges 0.17–26 m/s. The experimental data was used to evaluate the performance of steady-state empirical and mechanistic models while estimating liquid holdup and pressure gradient under steady-state and oscillatory conditions. The purpose of this analysis is first to evaluate the accuracy of the models predicting the liquid holdup and pressure gradient under steady-state conditions. Then, after evaluating the models under state-steady conditions, the same models are used to predict the same parameters for oscillatory and periodic conditions for similar gas and liquid velocities. The transient multiphase flow simulator OLGA, which has been widely used in the oil and gas industry, was implemented to model one oscillatory case to evaluate the prediction improvement while using a transient instead of a steady-state model to predict oscillatory flows. For the model with best performance for steady-state pressure gradient prediction, the absolute percentage error is 12% for Uls = 0.02 m/s and 5% for Uls = 0.3. For oscillatory conditions, the absolute percentage error is 30% for Uls = 0.02 m/s and 4% for Uls = 0.3. OLGA results underpredict the experimental pressure gradient under oscillatory conditions with errors up to 30%. Therefore, it was possible to conclude that the models can predict the average of the oscillatory data almost as well as for steady-state conditions.


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