Simulation of Transient Two-Phase Flow in Pipelines

1986 ◽  
Vol 108 (3) ◽  
pp. 202-206 ◽  
Author(s):  
Y. Sharma ◽  
M. W. Scoggins ◽  
O. Shoham ◽  
J. P. Brill
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Empirical Correlations ◽  
Liquid Holdup ◽  
System Of Difference Equations ◽  
Two Phase ◽  
Wet Gas ◽  
Friction Factors ◽  
Sequential Solution ◽  
Implicit Finite Difference

The laws of conservation of mass and linear momentum were applied to a two-phase mixture to formulate a mathematical model which simulates isothermal, transient two-phase flow of gas and liquid in a pipeline. Liquid holdup and friction factors were incorporated via existing empirical correlations, and the black oil method was used to describe interphase mass transfer. Implicit finite difference analogues were derived for the nonlinear set of partial differential equations which constituted the basis of the model. The system of difference equations was solved using a sequential solution algorithm implementing a Newton-Raphson iterative procedure. The numerical model formulated was used to predict the performance of an existing wet gas pipeline to establish the validity of the model. Example simulation runs were used to provide insights into the nature of transient two-phase flow.

Empirical Correlations for Prediction Slug Liquid Holdup on Slug-Pseudo-Slug and Slug-Churn Transitions in Vertical and Inclined Two-Phase Flow

2021 ◽  
pp. 1-13
Author(s):  
Ghassan H. Abdul-Majeed ◽  
Abderraouf Arabi ◽  
Gabriel Soto-Cortes
Keyword(s):  
Two Phase Flow ◽  
Liquid Velocity ◽  
Superior Performance ◽  
Phase Flow ◽  
Liquid Viscosity ◽  
Empirical Correlations ◽  
Liquid Holdup ◽  
Two Phase ◽  
Experimental Database ◽  
Transition Models

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.

Liquid holdup measurement in horizontal oil–water two-phase flow by using concave capacitance sensor

Measurement ◽  
2014 ◽  
Vol 49 ◽  
pp. 153-163 ◽  
Author(s):  
Zhao An ◽  
Jin Ningde ◽  
Zhai Lusheng ◽  
Gao Zhongke
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Capacitance Sensor ◽  
Liquid Holdup ◽  
Two Phase ◽  
Oil Water

Wet Gas Flow Metering Based on Differential Pressure and BSS Techniques

2011 ◽  
Vol 383-390 ◽  
pp. 4922-4927
Author(s):  
Peng Xia Xu ◽  
Yan Feng Geng
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Differential Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Metering ◽  
Wet Gas

Wet gas flow is a typical two-phase flow with low liquid fractions. As differential pressure signal contains rich information of flow parameters in two-phase flow metering, a new method is proposed for wet gas flow metering based on differential pressure (DP) and blind source separation (BSS) techniques. DP signals are from a couple of slotted orifices and the BSS method is based on time-frequency analysis. A good relationship between the liquid flow rate and the characteristic quantity of the separated signal is established, and a differential pressure correlation for slotted orifice is applied to calculate the gas flow rate. The calculation results are good with 90% relative errors less than ±10%. The results also show that BSS is an effective method to extract liquid flow rate from DP signals of wet gas flow, and to analysis different interactions among the total DP readings.

Liquid Holdup Correlations for Inclined Two-Phase Flow

1983 ◽  
Vol 35 (05) ◽  
pp. 1003-1008 ◽  
Author(s):  
Hemanta Mukherjee ◽  
James P. Brill
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Liquid Holdup ◽  
Two Phase

Computer Programming Simulation of Two-Phase Flow Pipelines Using Mechanistic and Semi-Empirical Models

2006 ◽  
Author(s):  
Ahmad Fazeli ◽  
Ali Vatani
Keyword(s):  
Pressure Drop ◽  
Flow Regime ◽  
Two Phase Flow ◽  
Empirical Models ◽  
Intermittent Flow ◽  
Phase Flow ◽  
Liquid Holdup ◽  
Two Phase ◽  
Segregated Flow ◽  
Semi Empirical

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.

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