A New Model for Dispersed Multi-Layer Oil-Water Flow

Author(s):  
Subash S. Jayawardena ◽  
Banu Alkaya ◽  
Clifford L. Redus ◽  
James P. Brill

Abstract Flow patterns observed in near-horizontal oil-water two-phase flows are quite different from those in gas-liquid flows. Experience with gas-liquid flows suggests that the mechanisms governing the flow behavior are flow-pattern dependent. However, little attention has been given to modeling flow patterns observed only in liquid-liquid systems. Such flow patterns include an oil-in-water dispersion flowing on top of a water layer and the simultaneous flow of dispersions of water-in-oil and oil-in-water as separate layers. A new mechanistic model is developed for one such flow pattern in horizontal and near-horizontal pipelines. The model combined the two-fluid model used for stratified flows with the homogeneous model used for dispersed flows. This paper presents that model, and shows that the new model can predict the pressure gradient as well as the holdup. The model results are compared with those from two other models, the stratified flow model and the homogeneous model. The new model predictions are also compared with available experimental data.

Author(s):  
Antonio C. Bannwart ◽  
Oscar M. H. Rodriguez ◽  
Carlos H. M. de Carvalho ◽  
Isabela S. Wang ◽  
Rosa M. O. Vara

Abstract This paper is aimed to an experimental study on the flow patterns formed by heavy crude oil (488 mPa.s, 925.5 kg/m3 at 20 °C) and water inside vertical and horizontal 1 in. pipes. The interfacial tension was 29 dynes/cm. Effort is concentrated into flow pattern characterization, which was visually defined. The similarities with gas-liquid flow patterns are explored and the results are expressed in flow maps of the superficial velocities. In contrast with other studies, the annular flow pattern (‘core annular flow’) was observed in both horizontal and vertical test sections. In fact this flow pattern typically occurs in heavy oil-water flows at low water input fractions. Because of the practical importance of core flow in providing an effective means for heavy oil production and transportation, this paper discusses two criteria that favor its occurrence in pipes.


2004 ◽  
Vol 126 (3) ◽  
pp. 184-189 ◽  
Author(s):  
Antonio C. Bannwart ◽  
Oscar M. H. Rodriguez ◽  
Carlos H. M. de Carvalho ◽  
Isabela S. Wang ◽  
Rosa M. O. Vara

This paper is aimed to an experimental study on the flow patterns formed by heavy crude oil (initial viscosity and density 488 mPa s, 925.5kg/m3 at 20°C) and water inside vertical and horizontal 2.84-cm-i.d. pipes. The oil-water interfacial tension was 29 dyn/cm. Effort is concentrated into flow pattern characterization, which was visually defined. The similarities with gas-liquid flow patterns are explored and the results are expressed in flow maps. In contrast with other studies, the annular flow pattern (“core annular flow”) was observed in both horizontal and vertical test sections. These flow pattern tends to occur in heavy oil-water flows at low water input fractions. Because of the practical importance of core flow in providing an effective means for heavy oil production and transportation, this paper discusses criteria that favor its occurrence in pipes.


Author(s):  
Takeyuki Ami ◽  
Noriko Nakamura ◽  
Hisashi Umekawa ◽  
Mamoru Ozawa ◽  
Masahiro Shoji

Experimental investigation was conducted with CO2 at high pressure, ranging 5.0 to 6.5 MPa, in horizontal mini-channels of 0.51, 1.0 and 2.0 mm in diameters. In smaller bores tube, e.g. 0.51 and 1.0 mm, the phase stratification is not serious and the flow pattern becomes quasi-axi-symmetric, while in 2.0 mm or larger tubes phase stratification becomes significant as in conventional sized tubes. This phase stratification, together with the intermittent flow behavior, causes the heat transfer deterioration at the upper wall. Existing criteria as a whole were insufficient in predicting flow patterns. In order to predict complicated two-phase flow behavior, including inherent void fraction fluctuation and flow patterns, the discrete bubble model based on a pattern dynamics approach was developed, so as to be applicable to the horizontal mini-channels. The simulated void fraction fluctuations successfully provided not only the flow pattern maps in terms of statistical properties, but also quantitative estimation of the heat transfer deterioration at the upper wall of the tube of 2.0 mm in diameter. Existing correlations were evaluated through the comparison with the present experimental data, and a nucleate boiling mode was found a dominant mode over the boiling heat transfer at high pressure in mini-channels.


Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2077
Author(s):  
Guishan Ren ◽  
Dangke Ge ◽  
Peng Li ◽  
Xuemei Chen ◽  
Xuhui Zhang ◽  
...  

A series of experiments were conducted to investigate the flow pattern transitions and water holdup during oil–water–gas three-phase flow considering both a horizontal section and a vertical section of a transportation pipe simultaneously. The flowing media were white mineral oil, distilled water, and air. Dimensionless numbers controlling the multiphase flow were deduced to understand the scaling law of the flow process. The oil–water–gas three-phase flow was simplified as the two-phase flow of a gas and liquid mixture. Based on the experimental data, flow pattern maps were constructed in terms of the Reynolds number and the ratio of the superficial velocity of the gas to that of the liquid mixture for different Froude numbers. The original contributions of this work are that the relationship between the transient water holdup and the changes of the flow patterns in a transportation pipe with horizontal and vertical sections is established, providing a basis for judging the flow patterns in pipes in engineering practice. A dimensionless power-law correlation for the water holdup in the vertical section is presented based on the experimental data. The correlation can provide theoretical support for the design of oil and gas transport pipelines in industrial applications.


SPE Journal ◽  
2016 ◽  
Vol 22 (01) ◽  
pp. 353-364 ◽  
Author(s):  
Zhiming Wang ◽  
Quan Zhang ◽  
Quanshu Zeng ◽  
Jianguang Wei

Summary In this article, a more-general flow-pattern classification of oil/water two-phase flow in the horizontal wellbore is proposed first according to the theoretical analysis and previous research achievements, on the basis of which a simplification is then performed through reasonable incorporation, and the ultimate flow patterns considered for modeling are reduced to two categories containing only six standard patterns. By use of the classical two-fluid and homogeneous modeling methodologies stemming from oil/water two-phase flow in conventional pipes, combined with the simplified classification, a mechanistic model is developed to predict the flow characteristics including the flow patterns and pressure losses for oil/water two-phase variable-mass flow in the horizontal wellbore. Model implementation is performed on the basis of the universal principle that a system will stabilize to the equilibrium state of minimum energy. Overall performance of the mechanistic model is then validated against the new data sets measured upon a large-scale experimental apparatus at the China University of Petroleum (CUP), which is designed and constructed to simulate the gas/oil/water multiphase flow in horizontal wellbores with wall mass transfer. Results show that the model developed in this paper can not only properly predict the flow patterns of oil/water two-phase flow in the horizontal wellbore, but also has high prediction accuracy for the pressure drops. Compared with the new experimental data for oil/water two-phase variable-mass flow that covers a series of input water-volumetric fractions ranging from 10 to 90%, the highest absolute average percentage error of the new unified model is 12% and the whole error is 9.2%, which demonstrates an acceptable performance. Investigations conducted in this study further enrich and develop the theory of hydrodynamic calculation for oil/water flow in the horizontal wellbore with wall influx.


Author(s):  
Shinpei Mizuki ◽  
Toshimichi Sakai ◽  
Ichiro Watanabe

An Investigation of the flow patterns within the centrifugal and mixed-flow impeller channel were performed. The velocity distributions within the impeller channel and blade surface pressure of the centrifugal and mixed-flow impellers were closely examined by experiment and the flow behavior within these impellers were clarified. The incompressible and inviscid flow within the impellers having straight radial blades were also derived analytically. The present authors assumed an outermost boundary of the relative eddy at the impeller exit periphery and corrected the analytical results. The corrected analytical results thus obtained showed good coincidence with the experimental data.


Author(s):  
Satya A. Putra ◽  
Richard L. Christiansen ◽  
James P. Brill

Abstract Comprehensive mechanistic models for two-phase flow in pipes have been proposed by several authors. These models predict pressure gradients for bubble, dispersed bubble, churn, slug, and annular flow patterns. The churn flow pressure gradient is often formulated based on a homogeneous model or modification of a slug flow model. A new mechanistic model for churn flow in vertical two-phase flow in pipes has been formulated applying two-fluid model concepts. The two-fluid model for churn flow is developed by defining the mass and momentum balances for gas and liquid phases. An interfacial interaction term is introduced to the balance equations defining the interaction between phases. Pressure drops calculated from this model and other methods available in the literature are compared with measured churn flow data from the Tulsa University Fluid flow Projects (TUFFP) databank. Results show that the proposed churn flow model performs better than all other methods considered.


2011 ◽  
Vol 66-68 ◽  
pp. 1187-1192 ◽  
Author(s):  
Hai Qin Wang ◽  
Yong Wang ◽  
Lei Zhang

Experiments were conducted in a horizontal multiphase flow test loop (50mm inner diameter, 40m long) to study the flow patterns for oil-gas-water three-phase flow and the pressure gradient fluctuation based on flow patterns. Using new methods of definition, 12 types of flow patterns were obtained and phase distribution characteristics of each pattern were analyzed. A new flow pattern (SW║IN) was firstly found in this work. Characteristics of the pressure gradient based on 7 flow patterns were carefully discussed. It was found that the pressure gradient increased with the increase of gas superficial velocity and oil-water mixture velocity. However, characteristics of the pressure gradient became complex with the increase of input water cut. The influence of flow structure of oil-water two-phase should be fully considered.


1999 ◽  
Vol 121 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J. O̸. Tengesdal ◽  
C. Sarica ◽  
Z. Schmidt ◽  
D. Doty

A comprehensive mechanistic model is formulated to predict flow patterns, pressure drop, and liquid holdup in vertical upward two-phase flow. The model identifies five flow patterns: bubble, dispersed bubble, slug, churn, and annular. The flow pattern prediction models are the Ansari et al. (1994) model for dispersed bubble and annular flows, the Chokshi (1994) model for bubbly flow, and a new model for churn flow. Separate hydrodynamic models for each flow pattern are proposed. A new hydrodynamic model for churn flow has been developed, while Chokshi’s slug flow model has been modified. The Chokshi and Ansari et al. models have been adopted for bubbly and annular flows, respectively. The model is evaluated using the expanded Tulsa University Fluid Flow Projects (TUFFP) well data bank of 2052 well cases covering a wide range of field data. The model is also compared with the Ansari et al., (1994), Chokshi (1994), Hasan and Kabir (1994), Aziz et al. (1972), and Hagedorn and Brown (1964) methods. The comparison results show that the proposed model performs the best and agrees well with the data.


2015 ◽  
Vol 26 (03) ◽  
pp. 1550034 ◽  
Author(s):  
Mei-Shuang Ding ◽  
Ning-De Jin ◽  
Zhong-Ke Gao

The simultaneous flow of oil and water through a horizontal pipe is a common occurrence during petroleum industrial processes. Characterizing the flow behavior underlying horizontal oil–water flows is a challenging problem of significant importance. In order to solve this problem, we carry out experiment to measure multivariate signals from different flow patterns and then propose a novel modality transition-based network to analyze the multivariate signals. The results suggest that the local betweenness centrality and weighted shortest path of the constructed network can characterize the transitions of flow conditions and further allow quantitatively distinguishing and uncovering the dynamic flow behavior underlying different horizontal oil–water flow patterns.


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