Phase Flow Measurement Research Articles

Exsolution effects in CO2 huff-n-puff enhanced oil recovery: Water-Oil-CO2 three phase flow visualization and measurements by micro-PIV in micromodel

CO2 huff-n-puff is one of the most important methods to enhanced oil recovery, which can simultaneously improve oil production and achieve CO2 geological storage. Due to the fluctuation of formation pressure, water-oil-CO2 three phase migration in porous structures was affected significantly by supercritical CO2 exsolution and expansion. However, the existing research on phase distribution is not enough to understand the mechanism of three-phase migration and the essential processes beneath the phase distribution are still not clear. Here, we developed a high-temperature and high-pressure micro-PIV (Particle Image Velocimetry) and fluorescence visualization experimental system (10 MPa, 50°C), which realized the simultaneous measurement of the velocity field and phase distribution of the water-oil-CO2 three-phase. The multiphase migration process under different wettability conditions during the supercritical-subcritical CO2 exsolution were captured. The results showed that the exsolution induced CO2 bubbles expansion in aqueous and oil phase blocked the preferential migration passage and dominated different multiphase migration mechanisms under different wettability. It was found that in water-wet condition, the aqueous phase can still migrate downstream through the water film between the CO2/oil and the wall, unable to further drive CO2/oil downstream. While in oil-wet condition, the aqueous phase eventually broke through the oil phase blocked at throats and formed a new preferential migration passage, pushing part of the oil phase encapsulating CO2 bubbles downstream. Our research reveals the multiphase migration mechanism beneath the phase distribution under different wettability during the exsolution process of the huff-n-puff, which provides a new insight for CO2 enhanced oil recovery and geological storage.

Phase separation and flow measurement of dilute bubbly jet with 2-D PIV and LIF

A measurement technique with a combination of PIV and LIF is suggested to measure gas-phase and liquid phase separately to resolve flow structures of a bubbly jet. In the bubbly jet, distribution of the bubble population shows a Gaussian-like function but translated outward. Spreading nature of each phase does not correspond to each other due to lack of the number of bubbles to be redistributed.

Study of Deformation and Breakup of Submillimeter Droplets’ Spray in a Supersonic Nozzle Flow

The problem of secondary atomization of droplets is crucial for many applications. In high-speed flows, fine atomization usually takes place, and the breakup of small droplets determines the final products of atomization. An experimental study of deformation and breakup of 15–60 µm size droplets in an accelerated flow inside a converging–diverging nozzle is considered in the paper. Particle image velocimetry and shadow photography were employed in the experiments. Results of gas and liquid phase flow measurements and visualization are presented and analyzed, including gas and droplets’ velocity, shape and size distributions of droplets. Weber numbers for droplets’ breakup are reported. For those small droplets at low Weber numbers, the presence of well-known droplets’ breakup morphology is confirmed, and rare “pulling” breakup mode is detected and qualitatively described. For the “pulling” breakup mode, a consideration, explaining its development in smaller droplets through shear stress effect, is provided.

Gas-liquid two-phase flow measurement by combining a Coriolis flowmeter with a flow conditioner and analytical models

Abstract In oil-gas fields, two phase flow measurement of liquid-gas mixture for the whole Gas Void Fraction (GVF) range remains a challenging task. Coriolis flow meter is proven to be one of the most accurate device for single phase flow measurement. However, for two phase flow metering, its accuracy gets altered for liquid continuous phase (respectively gas continuous phase) in case of GVF that exceeds 20% (respectively low GVF that is lower than 80%). This paper presents a new Coriolis-based two phase flow meter (TPFM) that uses an upstream inline flow conditioner which separates liquid (i.e. water in this paper) from gas. Each of the gas dominant phase and liquid dominant phase are carried by two outlets, namely gas and liquid outlets respectively. A Coriolis flow meter and an actuated valve are placed in each outlet to measure and regulate the GVF that passes in each line. A new measurement algorithm based on a multistage artificial neural network (ANN) and which explores the physical model of the Coriolis flow meter is also suggested. This latest combines the pressure-volume-temperature (PVT) and bubble theory models to estimate the amount of gas (respectively liquid) dissolved in the liquid phase (respectively gas phase). Experimental results that were conducted on a multiphase flow loop reveals that for the whole GVF range (i.e. 0 to 100% GVF), the absolute value of the relative error on both the mass flow rate and density does not exceed 2.5%. This suggests that the proposed TPFM can be considered as a new non-hazardous alternative for accurate two phase flow measurement.

Phase Content and Flow Measurement of Bubble Flow based on New Experimental Pipeline

Phase Content and Flow Measurement of Bubble Flow based on New Experimental Pipeline

Experimental and Numerical Study on Gas-Liquid Two-Phase Flow Behavior and Flow Induced Noise Characteristics of Radial Blade Pumps

Miniature drainage pumps with a radial blade are widely used in situations with critical constant head and low noise requests, but the stable operation state is often broken up by the entraining gas. In order to explore the internal flow characteristics under gas–liquid two phase flow, pump performance and emitted noise measurements were processed under different working conditions. Three-dimensional numerical calculations based on the Euler inhomogeneous model and obtained experimental boundaries were carried out under different inlet air void fractions (IAVFs). A hybrid numerical method was proposed to obtain the flow-induced emitted noise characteristics. The results show there is little influence on pump characteristics when the IAVF is less than 1%. The pump head slope degradation was found to increase with air content. The bubbles adhere to the impeller hub on the blade’s suction side and spread to the periphery with a big IAVF, leading to unstable operation. It is obvious that vortices appear inside the impeller flow passage as IAVF reaches 6.5%. The two-phase flow pattern has a small effect on the characteristic frequency distribution of pressure fluctuation and emitted noise, but the corresponding pulsation intensity and noise level will increase. The study could provide some reference for low noise design of the drainage pump.

Численное моделирование процесса дегазации газожидкостной смеси в гидроциклоне

Centrifugal separators — hydrocyclones — are widely used in many areas of the national economy to separate mixtures of substances of different densities. Hydrocyclones can be used for phase separation in oil, water and gas flow measurement units. The flow from the well is initially a three-phase mixture. The hydrocyclone separates the gas and liquid phases at the inlet of the measuring unit, which are then transferred to separate gas and liquid measurement units. Maintaining the accuracy of the phase flow measurement when using hydrocyclones in the measuring units requires high quality separation over a wide range of flow rates and phase contents. One of the directions of forecasting the characteristics of the separation process is based on the numerical solution of the equations of hydrodynamics of multiphase flows. Modern software of computational hydrodynamics allows to solve problems of such class in three-dimensional statement and thus to estimate efficiency of work of the device and its metrological characteristics.<br> This paper studies the processes of separation of gas-liquid mixture in hydrocyclone at different volume gas content and phase flow rates. The authors present a mathematical model with indication of the main assumptions and formulate the boundary conditions of the problem. Calculations were carried out on the open platform OpenFOAM with the use of interFoam solver. The results of numerical modeling have determined the basic structures of currents in the hydrocyclone. The influence of the initial gas content on the separation efficiency at different flow rates is investigated. The main reasons for the decrease in separation efficiency at low gas content values are revealed. In addition, the influence of the guiding elements on the separation process is considered.

Experimental Measurement and CFD Simulation for Characterization of Coriolis Flowmeter Performance

Gas-liquid two-phase flow measurement is challenging in comparison to single phase flow measurement as their dynamics are more complex. This study aims to investigate the performance of a U shape Coriolis mass flowmeter (CMF) to measure gas liquid two-phase flow via both experimental measurements and numerical simulation. It was observed from both measured and simulation results that the measurement performance of CMF was mainly affected by variation of mixture density and variation of flow pattern associated with gas entrainment. The findings provide fundamental fluidic dynamics of on-line multiphase flow measurements in harsh environments.

Investigation on Measurement of Size and Concentration of Solid Phase Particles in Gas‐Solid Two Phase Flow

Gas-solid two phase flow measurements have a wide range of applications in industrial production and scientific research. Based on optical principle and image processing, a measurement method of solid phase particle size and concentration of gas-solid two phase flow was presented, and an experimental system was built. By theoretical analysis and image processing algorithms, solid phase particle sizes and concentrations in gas-solid two phase flow were achieved.

Modeling Critical Flow through Choke for a Gas-condensate Reservoir Based on Drill Stem Test Data

Gas-condensate reservoirs contain hydrocarbon fluids with characteristics between oil and gas reservoirs and a high gas-liquid ratio. Due to the large gas-liquid ratio, wellhead choke calculations using the empirical equations such as Gilbert may contain considerable error. In this study, using drill stem test (DST) data of a gas-condensate reservoir, coefficients of Gilbert equation was modified; 26.7% of DST data has uncertainty. In these data, due to a problem of flow transmitter, the water flow rate is recorded equal to zero. This makes the mean absolute error of 5% in the measuring of total liquid phase flow rate. Because of uncertainty in the water flow rate in some DST data, the coefficients were optimized for two sets of data to investigate the effect of water flow rate on the calculations. The first dataset was the complete set of DST data, and, in the second, data were filtered with the elimination of uncertain data. The regression results showed that the whole data have a mean absolute error of 5.1%. For this regression, the uncertain data had a mean absolute error of 8.6%, while the error of the remaining data was 3.9%. In this case, for 38% of uncertain data, the mean absolute error was more than 10% indicating that these data are the major factor of the error. Mean absolute error for the filtered dataset was 3.0%. Error reduction was due to the elimination of data with uncertainty. In this case, 3% of the total data had a mean absolute error of more than 10%. In other words, 5% error of the liquid phase flow measurement that includes 26.7% of data caused an increase of 2.1% in the error of calculations. This showed that the elimination of uncertain data causes a remarkable reduction in error. To study the effect of temperature on choke calculations, wellhead temperature was considered as a variable in the Gilbert equation form. The regression results showed that the mean absolute error of 3.0% does not change, and the wellhead temperature has no considerable effect on the choke calculation accuracy.

Modeling Critical Flow through Choke for a Gas-condensate Reservoir Based on Drill Stem Test Data

Gas-condensate reservoirs contain hydrocarbon fluids with characteristics between oil and gas reservoirs and a high gas-liquid ratio. Due to the large gas-liquid ratio, wellhead choke calculations using the empirical equations such as Gilbert may contain considerable error. In this study, using drill stem test (DST) data of a gas-condensate reservoir, coefficients of Gilbert equation was modified; 26.7% of DST data has uncertainty. In these data, due to a problem of flow transmitter, the water flow rate is recorded equal to zero. This makes the mean absolute error of 5% in the measuring of total liquid phase flow rate. Because of uncertainty in the water flow rate in some DST data, the coefficients were optimized for two sets of data to investigate the effect of water flow rate on the calculations. The first dataset was the complete set of DST data, and, in the second, data were filtered with the elimination of uncertain data. The regression results showed that the whole data have a mean absolute error of 5.1%. For this regression, the uncertain data had a mean absolute error of 8.6%, while the error of the remaining data was 3.9%. In this case, for 38% of uncertain data, the mean absolute error was more than 10% indicating that these data are the major factor of the error. Mean absolute error for the filtered dataset was 3.0%. Error reduction was due to the elimination of data with uncertainty. In this case, 3% of the total data had a mean absolute error of more than 10%. In other words, 5% error of the liquid phase flow measurement that includes 26.7% of data caused an increase of 2.1% in the error of calculations. This showed that the elimination of uncertain data causes a remarkable reduction in error. To study the effect of temperature on choke calculations, wellhead temperature was considered as a variable in the Gilbert equation form. The regression results showed that the mean absolute error of 3.0% does not change, and the wellhead temperature has no considerable effect on the choke calculation accuracy.

MULTI PHASE FLOW MEASUREMENTS WITH THE APPLICATION OF ECT/ERT DECART MULTIMODALITY TOMOGRAPH

The multi-phase flow measurements are very important tasks in many areas of industrial processes applications. One of them is undersea exploration of oil in the petroleum industry. The submitted paper presents application of DECART tomograph designed and built in Lodz University of Technology - together with combined measurements of signals acquired from gamma ray measurement system. Use of all measuring modalities allowed for performing measurements of a flow composed of sea water, oil and gas. The paper presents theoretical principles applied to design multimodality tomograph and results of experiments performed in the University of Bergen. Measurement confirmed that multi-modality approach allows giving fast and reliable on-line results of measurements of composition of multi-phase flow. Applied algorithms allowed to speed up on-line measurements and presenting results in a form required in industrial applications. The derived conclusions can be used as guidelines for preparation of industrial applicable construction of tomograph.

Different configurations of capacitance sensor for gas/oil two phase flow measurement: An experimental and numerical study

In this paper, an experimental investigation and numerical study were performed on different electrode configurations for oil-air two phase flow measurement in different patterns. The main electrode configurations are: double ring, concave and double helix that can be compared in terms of sensitivity and phase distribution immunity. For this purpose, finite element simulations were carried out to compare electrode configurations as well as experimental study. Also a new electrode shape (TRFLC) was proposed and compared with the others. The simulation results show different sensitivity for each flow pattern: for stratified regime, TRFLC and for annular regime, concave and helical shapes were more sensitive. Concave shape was strongly dependent on the flow pattern while helical and ring show less dependency. Then, an experimental set up was constructed for oil-air two phase flow in a 26.6 ID horizontal pipe. Also, a capacitance sensor with high sensitivity was designed, using those electrode configurations, to measure small changes in the capacitance values of oil-air two phase flow and converting to voltage by a transducer circuit. The sensor responses for each configuration show TRFLC and concave had the most overall sensitivity for the pipe filled with oil and air which is consistent with the results of simulation. Flow pattern detection with the concave capacitance was clearly possible without the need for signal processing, regimes such as bubbly, slug, plug and wavy, and gas-oil ratio was obtained using helical type with an absolute percentage error less than 8%. In summary, if the main objective is identification of flow regime, then the TRFLC or concave shape is preferred and on the other hand, helical shape is favored if measurement of gas fraction is the target.

The Simulation Analysis of Effect with Particles in Different Sizes on Ultrasonic Measurement of Gas-solid Two Phase Flow

Gas-solid two phase flow measurements have found a wide range of applications in industrial production and scientific research. A simulation model of gas-solid two phase flow is made by the finite element software, and the signals from an ultrasonic wave receiver are analyzed with particles in different size and ultrasonic waves in different frequency, which contribute some advice for designing sensors of gas-solid two phase flow ultrasonic measurement.

Research on Image Reconstruction Algorithms for Tuber Electrical Resistance Tomography System

The application of electrical resistance tomography (ERT) technology has been expanded to the field of agriculture, and the concept of TERT (Tuber Electrical Resistance Tomography) is proposed. On the basis of the research on the forward and the inverse problems of the TERT system, a hybrid algorithm based on genetic algorithm is proposed, which can be used in TERT system to monitor the growth status of the plant tubers. The image reconstruction of TERT system is different from the conventional ERT system for two phase-flow measurement. Imaging of TERT needs more precision measurement and the conventional ERT cares more about the image reconstruction speed. A variety of algorithms are analyzed and optimized for the purpose of making them suitable for TERT system. For example: linear back projection, modified Newton-Raphson and genetic algorithm. Experimental results showed that the novel hybrid algorithm is superior to other algorithm and it can effectively improve the image reconstruction quality.

Experimental Studies on Void Fraction Measurement on Air-Lift Loop with Multiple Risers

Online, continuous two phase flow measurements is often necessary for analysis of the two phase flow particularly in oil and gas, nuclear energy and chemical processing industries. Reliable measurements of void fraction and flow pattern identification are important for accurate modeling of two phase systems. Void fraction is one of the most important parameters used to characterize two-phase flows. It is the key physical value for determining numerous other important parameters, such as the two-phase density and the two-phase viscosity, for obtaining the relative average velocity of the two phases and is of fundamental importance in models for predicting the flow pattern transitions, heat transfer and pressure drop. Experiments are performed in atmospheric vertical air-water flows for void fraction measurement between the pipe size of 12.5mm diameter to 4.5mm diameter to emphasize on developing the measuring techniques of two-phase flow void fraction by using ‘Conducting probe circuit’ which uses a ‘needle probe’ for measurement of void fraction in an air lift loop. The process involves the immersion of probe tip in two phase mixture in order to detect the two phases instantaneously present at the tip and the corresponding readings for the measurement of void fraction are obtained from the processing circuit.

An experiment study on fluid heat and mass transfer properties in porous media using MRI

The objective of this study was to understand fluid heat and mass transfer processes in porous media with different pore structures. High-resolution Magnetic Resonance Imaging was used to measure fluid flow velocity and temperature maps in porous media. Firstly, three orthogonal velocity components (Vx, Vy, and Vz) of single phase flow measurement were evaluated. The flow distribution in porous media is rather heterogeneous, and it is consistent with heterogeneous pore structure, and the velocity in large pore is high. Then we presented initial results from the extension of this work to two-phase flow. The CO2 channeling phenomena were obvious. And the CO2 velocity was calculated from saturation of water. Finally, the linearity relationship between temperature and the MRI parameter was determined for porous media, and we measured the temperature distribution of water saturated porous media. The study provides useful data for heat and mass process during CO2 storage.

Electrical resistance tomography (ERT) for flow and velocity profile measurement of a single phase liquid in a horizontal pipe

Electrical resistance tomography (ERT) is a novel, simple, and robust method of process imaging which uses non-invasive sensors located on the periphery of vessels to reconstruct a cross-sectional image of the vessel interior. This method of imaging when conducted on two adjacent planes on a pipe provides the ability to extract flow information. Previous studies have investigated this application on multi-phase flows in which the secondary phase provided the required pulse conductivity variation. In these studies the velocity profile and flow regime were identified using the common cross-correlation technique.This study investigates the novel application of ERT to single phase flow and velocity profile measurement. For this purpose a new measurement technique is also developed which excludes the limitation of “pulse” conductivity change in the cross-correlation technique. This new technique has been applied to saline flow and velocity profile measurement using a “step” change in the flow conductivity. The effect of flow speed, ERT measurement frequency, secondary solution conductivity and addition volume has also been investigated and the optimum settings selected. The optimum settings for this experimental setup resulted in an average accuracy of 97.0% for a secondary solution with conductivity more than twice the primary solution conductivity and 94.8% for a secondary solution with conductivity ∼67% more than the primary solution conductivity. This application and accuracy level has been further confirmed through 13%, 24% and 47% total solids content whole and skim milk experiments which resulted in an average accuracy of over 98%.

Miniaturized liquid film sensor (MLFS) for two phase flow measurements in square microchannels with high spatial resolution

Two miniaturized liquid film sensors (MLFS) based on electrical conductance measurement have been developed and tested. The sensors are non-intrusive and produced with materials and technologies fully compatible and integrable with standard microfluidics. They consist of a line of 20 electrodes with a purpose-designed shape, flush against the wall, covering a total length of 5.00 and 6.68mm. The governing electronics achieve 10kHz of time resolution. The electrode spacing of the two sensors is 230μm and 330μm, which allows measurements of liquid films up to 150μm and 400μm for sensors MLFSA and MLFSB, respectively. The sensor characteristics were obtained by imposing static liquid films of known thickness on top of the actual sensor. Further dynamic measurements of concurrent air-water flow in a horizontal microchannel were performed. The line of electrodes is placed across the flow direction with an angle of 3.53° from the direction of flow, allowing for a spatial resolution perpendicular to the flow of 14.2μm for sensor MLFSA and 20.5μm for sensor MLFSB. The high time and spatial resolution allows for fast and accurate detection of the presence of bubbles, and even measurement of film thickness and bubble velocity. Further information, such as the bubble shape, can be gathered based on the shape of the liquid layer underneath the bubble, which is particularly important for heat transfer studies in microchannels.

Study on the Gas Holdup of Triangular Pitch and Square Pitch Sparger Geometry in Bubble Column

Gas holdup in a bubble column has been studied for triangular and square geometries of a pitch sparger. The investigation was carried out in a bubble column characterized by an aspect ratio equal to four. The column was made up of plexiglas, equipped with sparger. The top of the column was open to atmosphere. The column was also equipped with appropriate rotameters for gas phase flow measurement and control. The liquids used in experiments were: deionised water, glycerin (50 %) and butanol (1.5 %) with atmospheric air representing the gas phase. A high-speed digital video camera was employed for the measuring of bubble rise velocity. The recorded images are also used to obtain an insight into the coalescence/breakage mechanisms occurring during bubble formation at the vicinity of the sparger. Using the appropriate software, rise velocity of the bubbles after their detachment from the triangular and square pitch spargers can be obtained from recorded images for examined liquid and flow conditions. The effect of sparger’s geometry on the rise velocity of the bubbles was studied. An average gas holdup was estimated by bed expansion. The uncertainty of measurements is estimated to be less than 10 %. For two tested spargers, the transition point was determined to be independent from the pore size. It is also evident that the increase of liquid phase viscosity shifts the transition point to lower velocities. The only exception is a water whose transition velocity is lower than that of butanol solutions, despite of its higher viscosity. This behavior can be attributed to simultaneous effect of relatively low viscosity and high surface tension.