Investigation of Holdup and Pressure Drop Behavior for Oil-Water Flow in Vertical and Deviated Wells

1998 ◽  
Vol 120 (1) ◽  
pp. 8-14 ◽  
Author(s):  
J. G. Flores ◽  
C. Sarica ◽  
T. X. Chen ◽  
J. P. Brill
Keyword(s):  
Pressure Drop ◽  
Water Flow ◽  
Flow Patterns ◽  
Production Optimization ◽  
Pressure Gradients ◽  
Two Phase ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Inclination Angles ◽  
Oil Water

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.

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

2014 ◽  
Author(s):  
S. Alireza Hojati ◽  
Pedram Hanafizadeh
Keyword(s):  
Water Flow ◽  
Inclination Angle ◽  
Pressure Loss ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase ◽  
Inclination Angles ◽  
Oil Water ◽  
Pipe Inclination

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.

Effect of Water-Soluble Drag-Reducing Polymer on Flow Patterns and Pressure Gradients of Oil/Water Flow in Horizontal and Upward-Inclined Pipes

SPE Journal ◽  
2016 ◽  
Vol 22 (01) ◽  
pp. 339-352 ◽  
Author(s):  
A.. Abubakar ◽  
Y.. Al-Wahaibi ◽  
T.. Al-Wahaibi ◽  
A.. Al-Hashmi ◽  
A.. Al-Ajmi ◽  
...  
Keyword(s):  
Water Flow ◽  
Flow Patterns ◽  
Major Effect ◽  
Water Soluble ◽  
Experimental Investigations ◽  
Pressure Gradients ◽  
Volume Fractions ◽  
Continuous Flows ◽  
Oil Water ◽  
Drag Reducing Polymer

Summary Experimental investigations of flow patterns and pressure gradients of oil/water flow with and without drag-reducing polymer (DRP) were carried out in horizontal and upward-inclined acrylic pipe of 30.6-mm inner diameter (ID). The oil/water flow conditions of 0.1- to 1.6-m/s mixture velocities and 0.05–0.9 input oil-volume fractions were used, and 2,000 ppm master solution of the water-soluble DRP was prepared and injected at controlled flow rates to provide 40 ppm of the DRP in the water phase at the test section. The flow patterns at the water-continuous flows were affected by the DRP, whereas there were no tangible effects of the DRP at the oil-continuous flow regions. The upward inclinations shifted the boundaries between stratified flows and dual continuous flows, and the boundaries between dual continuous flows and water-continuous flows to lower mixture velocities. This means that the inclinations increased the rate of dispersions. The frictional pressure gradients for both with and without DRP slightly decreased with inclinations especially at low mixture velocities, whereas the significant increases in the total pressure gradients with the inclinations were more pronounced at low mixture velocities. The inclinations did not have a major effect on the drag reductions by the DRP at the high mixture velocities and low-input oil-volume fractions where the highest drag reductions recorded were 64% at 0° inclination and 62% at both + 5° and +10° inclinations. However, the inclinations increased the drag reductions as the input oil-volume fractions were increased before phase-inversion points.

Numerical modelling of two-phase oil–water flow patterns in a subsea pipeline

2016 ◽  
Vol 115 ◽  
pp. 135-148 ◽  
Author(s):  
Hassan Pouraria ◽  
Jung Kwan Seo ◽  
Jeom Kee Paik
Keyword(s):  
Numerical Modelling ◽  
Water Flow ◽  
Flow Patterns ◽  
Two Phase ◽  
Subsea Pipeline ◽  
Oil Water

A Machine Learning Approach to Predict the Pressure Gradient of Different Oil-Water Flow Patterns in a Horizontal Wellbore

2021 ◽  
Author(s):  
MD Ferdous Wahid ◽  
Reza Tafreshi ◽  
Zurwa Khan ◽  
Albertus Retnanto
Keyword(s):  
Machine Learning ◽  
Surface Tension ◽  
Surface Roughness ◽  
Pressure Gradient ◽  
Water Flow ◽  
Flow Patterns ◽  
Data Driven ◽  
Pressure Gradients ◽  
Horizontal Wellbore ◽  
Oil Water

Abstract Fluid pressure gradient in a wellbore plays a significant role to efficiently transport between source and separator facilities. The mixture of two immiscible fluids manifests in various flow patterns such as stratified, dispersed, intermittent, and annular flow, which can significantly influence the fluid’s pressure gradient. However, previous studies have only used limited flow patterns when developing their data-driven model. The aim of this study is to develop a uniform data-driven model using machine-learning (ML) algorithms that can accurately predict the pressure gradient for the oil-water flow with two stratified and seven dispersed flow patterns in a horizontal wellbore. Two different machine-learning algorithms, Artificial Neural Network (ANN) and Random Forest (RF), were employed to predict the pressure gradients. A total of 662 experimental points from nine different flow patterns were extracted from five sources that include twelve variables for different physical properties of oil-water, wellbore’s surface roughness, and input diameter. The variables are entrance length to diameter ratio, oil and water viscosity, density, velocity, and surface tension, between oil and water surface tension, surface roughness, input diameter, and flow pattern. The algorithms’ performance was evaluated using median absolute percentage error (MdAPE) and root mean squared error (RMSE). A repeated train-test split strategy was used where the final MdAPE and RMSE were computed from the average of all repetitions. The MdAPE and RMSE for the prediction of pressure gradients are 13.89% and 0.138 kPa/m using RF and 12.17% and 0.088 kPa/m using ANN, respectively. The ML algorithms’ ability to model the pressure gradient is demonstrated using measured vs. predicted analysis where the experimental data points are mostly located in close proximity of the diagonal line, indicating a suitable generalization of the models. Comparing the performance between RF and ANN shows that the latter algorithm’s prediction accuracy is significantly better (p<0.01).

An Experimental Investigation of Oil-Water Flow Patterns in Horizontal Pipes

2004 ◽  
Author(s):  
Hai-Yuan Yao ◽  
Jing Gong
Keyword(s):  
Experimental Data ◽  
Water Flow ◽  
Flow Patterns ◽  
Critical Conditions ◽  
New Classification ◽  
Two Phase ◽  
Factors Affecting ◽  
Horizontal Pipes ◽  
Transition Mechanism ◽  
Oil Water

In this paper, an experimental research on the oil-water liquid-liquid two-phase flow patterns and their transitions in horizontal pipes are carried out. According to online oil-water flow structures and the analysis of pressure drop signals., different flow patterns are defined and distinguished. A new classification for oil-water flow patterns is proposed. The flow pattern maps are obtained from the experimental data, and the factors affecting the transition mechanism of different flow regimes are discussed. In addition, some semi-theoretical criteria for the transition between different flow patterns are proposed. Especially, an accurate model is developed to predict the critical conditions for phase inversion. Comparisons of the proposed criteria with other experimental data show reasonable agreements.

Investigation of a Two-Phase Siphon: Pressure Drop Characteristics, Flow Prediction, and Flow Regime Change Prediction

Volume 3 ◽  
2004 ◽  
Author(s):  
J. Howard Arthur ◽  
Charles D. Morgan ◽  
Cory D. Engelhard ◽  
Berton Austin
Keyword(s):  
Pressure Drop ◽  
Flow Regime ◽  
Distribution Parameter ◽  
Regime Transition ◽  
Two Phase ◽  
Flow Rates ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Flow Regime Transition ◽  
Flux Model

In some nuclear power plants, a passive siphon breaking system is used to prevent the spent fuel tank from draining in the event of a break in the vertical leg of the heat exchanger piping. A hole is drilled in the horizontal leg of the piping. When the water level in the tank drops below the pipe level air is sucked into the system. When sufficient air is entrained in the pipe the siphon will break. A model to predict the flow rate in a vertical siphon was developed in reference 1 using the homogeneous flow model. The predicted flow rates were greater than measured flow rates. In order to improve the predictive capability, pressure drop measurements were obtained from ten foot vertical test sections with nominal diameters of 0.5, 0.75, 1.0, 1.25, 1.5, and 2.0 inches. Values of the distribution parameter, Co, for the drift flux model were determined from the pressure drop data. When the model of reference 1 is changed from homogeneous flow to drift flux model with the distribution parameter determined from the pressure drop data, good agreement with measured liquid flow rates is obtained. The improved model, along with the correlation for the siphon break condition obtained provides a good method for determining the hole size required to break the siphon. There is a paucity of data for two-phase flow regime transition where the flow is in the downward direction that is typical in a siphon. Flow regime transition data were obtained using the test sections listed above. The flow map of Oshinowo2 et al. gave a reasonable prediction of the transition from bubbly to slug flow. None of the references investigated gave an adequate prediction of the point where the siphon would break. A correlation for the siphon break point was developed.

Oil-Water Flow Visualization and Flow Regimes in a 3.7 mm Mini-Channel

2016 ◽  
Author(s):  
Kevin K. Bultongez ◽  
Melanie M. Derby
Keyword(s):  
Pressure Drop ◽  
Water Flow ◽  
Glass Tube ◽  
Flow Regimes ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Apparatus ◽  
Phase Liquid ◽  
Oil Water ◽  
Minor Losses

This study investigates adiabatic oil and water flow patterns in a 3.7-mm-inner-diameter borosilicate glass tube. A closed-loop flow apparatus was constructed and pressure drop was verified using single-phase liquid water. Minor losses were shown to be negligible, and 98% of the pressure drop occurred in the glass tube. Oil-water tests were conducted over a range of oil superficial velocities (0.27 < jo < 3.3 m/s) and water superficial velocities (0.07 < jw < 4.96 m/s). Annular, intermittent, and dispersed flow regimes were observed and shown. For nearly all cases, an annular water ring formed along the perimeter of the glass tube. Two-phase pressure drops are reported.

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