Experimental Study of Gas-Liquid Pressurization Performance and Critical Gas Volume Fractions of a Multiphase Pump

2021 ◽  
Author(s):  
Liang Chang ◽  
Qiang Xu ◽  
Chenyu Yang ◽  
Xiaobin Su ◽  
Xuemei Zhang ◽  
...  
Keyword(s):  
Liquid Flow ◽  
Volume Fraction ◽  
Extreme Points ◽  
Transition Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Multiphase Pump ◽  
Gas Liquid Flow ◽  
Relative Errors ◽  
Gas Volume

Abstract Gas entrainment may cause pressurization deterioration and even failure of pumps under conditions of high inlet gas volume fraction (GVF). When the inlet GVF increases to a critical value, an obvious deterioration performance of pump occurs. Air-water pressurization performance and inlet critical GVFs of a centrifugal multiphase pump are investigated experimentally under different inlet pressures and gas-liquid flow rates. To determine the first and second critical GVFs, a new method is proposed by computing the local extreme points of the second derivative of performance curves. New prediction correlations for two critical GVFs are established with relative errors lower than ±10% and ±8%. Boundaries of three different flow patterns and the transition flow rates are determined and presented by critical GVFs on the flow pattern diagram. Moreover, boundaries of maximum pressurization are determined by performance curve clusters and a power function correlation of gas-liquid flow rates when reaching the maximum pressurization is established. With the increase of inlet pressure from 1MPa to 5MPa, two-phase pressurization performance is significantly increased; occurrences of pressurization deterioration are obviously delayed with the first and second critical GVFs increasing by maximums of 8.2% and 7.1%.

Unified Model for Gas-Liquid Pipe Flow Via Slug Dynamics: Part 2 — Model Validation

2002 ◽  
Author(s):  
Hong-Quan Zhang ◽  
Qian Wang ◽  
Cem Sarica ◽  
James P. Brill
Keyword(s):  
Experimental Data ◽  
Liquid Flow ◽  
Pipe Flow ◽  
Flow Behavior ◽  
Two Phase ◽  
Flow Rates ◽  
Inclination Angles ◽  
Gas Liquid Flow ◽  
Extensive Experimental Data ◽  
Good Agreement

In Zhang et al. [1], a unified hydrodynamic model is developed for prediction of gas-liquid pipe flow behavior based on slug dynamics. In this study, the new model is validated with extensive experimental data acquired with different pipe diameters, inclination angles, fluid physical properties, gas-liquid flow rates and flow patterns. Good agreement is observed in every aspect of the two-phase pipe flow.

scholarly journals Effect of Gas Volume Fraction on the Energy Loss Characteristics of Multiphase Pumps at Each Cavitation Stage

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2293
Author(s):  
Jianwei Shi ◽  
Sijia Tao ◽  
Guangtai Shi ◽  
Wenwu Song
Keyword(s):  
Energy Loss ◽  
Volume Fraction ◽  
Axial Flow ◽  
Two Phase ◽  
Multiphase Pump ◽  
Cavitation Phenomenon ◽  
Flow Loss ◽  
Gas Volume Fraction ◽  
Critical Cavitation ◽  
Gas Volume

In the process of conveying a medium, when the inlet pressure is low, the cavitation phenomenon easily occurs in the pump, especially in the gas–liquid two-phase working condition. The occurrence of the cavitation phenomenon has a great impact on the performance of the multiphase pump. In this paper, the SST (sheard stress transport) k-ω turbulence model and ZGB (Zwart–Gerber–Belamri) cavitation model were used to simulate the helical axial flow multiphase pump (hereinafter referred to as the multiphase pump), and the experimental verification was carried out. The effect of gas volume fraction (GVF) on the energy loss characteristics in each cavitation stage of the multiphase pump is analyzed in detail. The study shows that the critical cavitation coefficient of the multiphase pump gradually decreases with the increase in GVF, which depresses the evolution of cavitation, and the cavitation performance of the multiphase hump is improved. The ratio of total loss and friction loss to total flow loss in the impeller fluid domain gradually increases with the development of cavitation, and the pressurization performance of the multiphase pump gradually decreases with the development of cavitation. The results of the study can provide theoretical guidance for the improvement of the performance of the multiphase pump.

Investigation of Gas-Liquid Flow Using Electrical Resistance Tomography and Wavelet Analysis Techniques for Early Kick Detection

2021 ◽  
Author(s):  
Abinash Barooah ◽  
Muhammad Saad Khan ◽  
Mohammad Azizur Rahman ◽  
Abu Rashid Hasan ◽  
Kaushik Manikonda ◽  
...  
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Electrical Resistance ◽  
Liquid Flow Rate ◽  
Volume Fraction ◽  
Gas Kick ◽  
Input Pressure ◽  
Gas Volume Fraction ◽  
Gas Liquid Flow ◽  
Gas Volume

Abstract Gas kick is a well control problem and is defined as the sudden influx of formation gas into the wellbore. This sudden influx, if not controlled, may lead to a blowout problem. An accidental spark during a blowout can lead to a catastrophic oil or gas fire. This makes early gas kick detection crucial to minimize the possibility of a blowout. The conventional kick detection methods such as the pit gain and flow rate method have very low sensitivity and are time-consuming. Therefore, it is required to identify an alternative kick detection method that could provide real-time readings with higher sensitivity. In this study, Electrical Resistance Tomography (ERT) and dynamic pressure techniques have been used to investigate the impact of various operating parameters on gas volume fraction and pressure fluctuation for early kick detection. The experiments were conducted on a horizontal flow loop of 6.16 m with an annular diameter ratio of 1.8 for Newtonian fluid (Water) with varying pipe inclination angle (0–10°) and annulus eccentricity (0–30%), liquid flow rate (165–265 kg/min), and air input pressure (1–2 bar). The results showed that ERT is a promising tool for the measurement of in-situ gas volume fraction. It was observed that the liquid flow rate, air input pressure and inclination has a much bigger impact on gas volume fraction whereas eccentricity does not have a significant influence. An increase in the liquid flow rate and eccentricity by 60% and 30% decreased the gas volume fraction by an average of 32.8% and 5.9% respectively, whereas an increase in the inclination by 8° increased the gas volume fraction by an average 42%. Moreover, it was observed that the wavelet analysis of the pressure fluctuations has good efficacy for real-time kick detection. Therefore, this study will help provide a better understanding of the gas-liquid flow and potentially provide an alternative method for early kick detection.

Visualization of Terrain-induced Slugging in W-shaped Pipeline

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Jungho Lee ◽  
Jaebum Park ◽  
Sangho Sohn
Keyword(s):  
Water Flow ◽  
Volume Fraction ◽  
Water Flow Rate ◽  
Slope Angle ◽  
Tidal Wave ◽  
Internal Diameter ◽  
Two Phase ◽  
Flow Phenomena ◽  
Gas Liquid Flow ◽  
Gas Volume

Gas-liquid two-phase flow in a circular pipeline is commonly encountered in an inclined pipeline of an offshore plant. To visualize gas-liquid flow phenomena in an inclined pipeline, the w-shaped transparent pipeline was fabricated with internal diameter of 2″ and slope angle of 25°. The terrain-induced slug flow in a steady-state was visualized at fixed water flow rate of 1 m3/hr and 80% GVF (Gas Volume Fraction). The air and water flow is initially maintained in stratified or wavy flow at t = 0 s. When the velocity difference between the air and water is high enough, the Kelvin-Helmholtz wave motion starts to occur just after at t = 0 s. As the wave reaches the top, the upward water flow is faced with the downward water flow in the main visualized region. When the airway is clogged, the air slug is formed at t = 0.02 s. When a huge tidal wave is observed at t = 0.1 s due to different velocity between the upward water and the downward water flow, the air slug travels at a greater velocity than the water flow. As the tidal wave enlarges its growth, the chaotic motion with scattered bubbles is exhibited at the gas-liquid interface. A series of the air slugging is periodically observed after near 0.5 s. At the second v-shaped pipeline, the slugging phenomena become even more severe due to an irregular water inflow from the first v-shaped pipeline.

Experimental Study Structure Of Gas-Liquid Flow In Rectangular Minichannel By Optical Methods

2015 ◽  
Vol 10 (3) ◽  
pp. 63-69
Author(s):  
Igor Kozulin ◽  
Vladimir Kuznetsov
Keyword(s):  
Liquid Flow ◽  
High Speed ◽  
Laser Scanning ◽  
Rectangular Channel ◽  
Optical Methods ◽  
Statistical Characteristics ◽  
Transition Flow ◽  
Two Phase ◽  
Beam Laser ◽  
Gas Liquid Flow

In this paper, using method of two-beam laser scanning and high-speed video was identified patterns of distribution phases in the cross-section of the rectangular channel 0.72 × 1.50 mm with hydraulic diameter of the order to capillary constant. The structure of the gas-liquid flow was studied including flow regimes and statistical characteristics of the two-phase flow in regime with elongated bubbles, transition flow and annular flow regime.

Experimental Visualization of Gas-Liquid Flow Patterns in a Centrifugal Rotor

2019 ◽  
Author(s):  
Henrique Stel ◽  
Edgar Minoru Ofuchi ◽  
Rafael Fabrício Alves ◽  
Sergio Chiva ◽  
Rigoberto E. M. Morales
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Volume Fraction ◽  
Flow Patterns ◽  
Centrifugal Pumps ◽  
Gas Volume Fraction ◽  
Gas Liquid Flow ◽  
Liquid Flows ◽  
Complex Phenomena ◽  
Gas Volume

Abstract Centrifugal pumps operating with gas-liquid flows can undergo severe performance degradation. This can be attributed to an effect of the gas phase on the liquid flow orientation in the pump impeller channels, which induces additional hydraulic losses that negatively affect the delivered head and flow rate. Effort to investigate the effect of many operating parameters on the pump performance under multiphase flows can be found on numerous experimental investigations. Few studies, however, bring together flow visualization to understand the physics behind the behavior of centrifugal pumps with gas-liquid flows. One issue is that pumps involve rotating parts, metallic casing and limited visual access, sometimes making it hard to interpret flow patterns and to understand complex phenomena, such as bubble breakup and coalescence. Such issues usually lead to unsatisfactory image quality, which in turn makes it difficult to extract quantitative data from the obtained images, such as gas volume fraction and bubble size distribution. In an attempt to overcome many difficulties of previous investigations, this work presents an experimental study aimed to visualize gas-liquid flow patterns in a centrifugal rotor prototype using a novel approach. The experimental apparatus uses a plane and transparent rotor, assembled with an intake pipe and a discharge chamber by means of a dynamic seal system that dismisses the use of an enclosing pump casing. This makes possible to use back illumination of the impeller for visualization, which in turn is done by using a camera attached to the impeller axis for filming in a rotating frame of reference. This setup, which is new in the open literature, provides high image contrast and sharpness for clear interpretation of the flow patterns found inside the rotor channels for a wide range of operating conditions. This advantage, in turn, allows using image processing for quantitative assessment of gas volume fraction distributions. Pressure rise versus flow rate curves are measured together to investigate the rotor performance degradation associated with the gas-liquid flow patterns for a range of liquid and gas flow rates. Information obtained with the designed experimental setup at controlled conditions help not just to bring further understanding to the complex phenomena involved with multiphase flows in rotating devices, but also in the direction of validating a numerical model for reliable simulations of gas-liquid flows in centrifugal pumps, which is lacking in the current literature.

Qualification of a New Multiphase Pump. the Setting of a New Standard

2021 ◽  
Author(s):  
Åge Hofstad ◽  
Tarje Olderheim ◽  
Magnus Almgren ◽  
Marianna Rondon ◽  
Edouard Thibaut ◽  
...  
Keyword(s):  
High Speed ◽  
Oil And Gas ◽  
Volume Fraction ◽  
Two Phase ◽  
Specific Product ◽  
Multiphase Pump ◽  
Gas Volume Fraction ◽  
Gas Market ◽  
Gas Volume ◽  
Winding Insulation

Abstract The recent trend in the oil industry is to save CAPEX and exploit every offshore field to increase production and maximize reserves. Also, deeper water and longer step-out is a challenge for new fields. The most adapted technology to unlock these reserves is the use of subsea boosting like a multiphase pump on the seafloor. Subsea boosting has been used for decades with well proven results, but up to now, some limitations in power and lift pressure exist. This new multiphase pump development has increased the potential pressure generation manyfold from the typical ΔP of 50 bar (725 psi) at the beginning of the project. Developing such a powerful two-phase pump driven by a liquid-filled motor requires a unique combination of expertise in machinery engineering, electrical engineering, fluid mechanics and rotor dynamics. The objective of the co-authors is to share this experience by bringing some insights on what it takes to develop, test, and qualify such specific product. Outlines of the methodology will be described, key results will be detailed, and lessons learnt will be presented. The new design was fully tested first component-wise and then for a full-size prototype. A wide process envelope was mapped during the final qualification program with 3,000 points tested in the range 2,000-6,000 RPM and 0 - 100% GVF (Gas Volume Fraction). Qualification tests concluded with more than 2,000 cumulative hours. The main challenges in this program were the development of an innovative multiphase impeller and the qualification of the first MPP (MultiPhase Pump) with a back-to-back configuration. Concerning the motor, the development includes a high speed 6,000 RPM, 6 MW liquid-filled induction motor and a new stator winding insulation cable. With this new product, the pump market is ready to overcome challenges to produce deeper and further reservoirs in a constant evolutive oil and gas market.

scholarly journals Effect of Thickness Ratio Coefficient on the Mixture Transportation Characteristics of Helical–Axial Multiphase Pumps

2020 ◽  
Vol 10 (1) ◽  
pp. 345
Author(s):  
Wei Han ◽  
Xing Li ◽  
Youliang Su ◽  
Min Su ◽  
Rennian Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Oil And Gas ◽  
Volume Fraction ◽  
Thickness Ratio ◽  
Two Phase ◽  
Multiphase Pump ◽  
Gas Volume Fraction ◽  
Gas Volume ◽  
Oil Gas ◽  
Transportation Characteristics

With the decrease of oil and gas resources on land, increased attention has been paid to multiphase oil–gas exploitation and the transportation technology represented by oil–gas multiphase pumps. The helical–axial multiphase pump has become the focus of research on oil and gas mixed transmission technology due to its relatively high operating efficiency and adaptability to a wide range of gas volume fraction changes. In order to investigate the thickness variation in the air foil from the hub to the shroud of the blade on the mixture transportation characteristics of the gas–liquid two-phase flow in a helical–axial pump, the thickness ratio coefficient ξ was introduced, and the hydraulic performance of the single compression unit with different thickness ratio coefficients was investigated. A single compression unit including an impeller, diffuser, inlet section and outlet section of a helical–axial multiphase pump. The hydraulic performance including the hydraulic head and efficiency was investigated by numerical simulation with the Eulerian multiphase model and the shear stress transport (SST) k-w turbulence model. In order to demonstrate the validity of the numerical simulation approach, the hydraulic head and efficiency of the basic model was measured based on a gas–liquid two-phase flow pump performance test bench. The simulation results agreed well with the experimental results; the error between the simulation results and experimental results of different inlet gas volume fractions was within 10% at the design point, which indicated the numerical simulation method can be used in the research. The thickness ratio coefficient ξ, which was taken as a variable, and the aggregation degree λ of the gas were introduced to analyze the gas–liquid mixture transportation characteristics of the pump. The thickness ratio coefficient was selected in a range from 0.8 to 1.8. The results showed that, for the same hub thickness, the head coefficient and efficiency increase, and the aggregation degree of gas decreases with the decreasing of the thickness ratio coefficient. The head coefficient of the modification multiphase pump was 5.8% higher in comparison to the base pump while the efficiency was 3.1% higher than that of the base pump, the aggregation degree of this model was the lowest, which was 30.3%; the optimal model in the research was the model of scheme 1 with ξ = 0.8. The accumulation of gas in the flow passage of the impeller could be delayed to the trailing edge of the blade by adjusting the thickness ratio coefficient, which produced a super-separated airfoil for helical–axial multiphase pumps and effectively ensured reliable operation under high gas volume fraction conditions. The accumulation area of gas was consistent with the area in which the gradient of turbulent kinetic energy was large.

Unified Model for Gas-Liquid Pipe Flow via Slug Dynamics—Part 2: Model Validation

2003 ◽  
Vol 125 (4) ◽  
pp. 274-283 ◽  
Author(s):  
Hong-Quan Zhang ◽  
Qian Wang ◽  
Cem Sarica ◽  
James P. Brill
Keyword(s):  
Experimental Data ◽  
Liquid Flow ◽  
Pipe Flow ◽  
Flow Behavior ◽  
Two Phase ◽  
Flow Rates ◽  
Inclination Angles ◽  
Gas Liquid Flow ◽  
Extensive Experimental Data ◽  
Good Agreement

In Zhang et al. [1], a unified hydrodynamic model is developed for prediction of gas-liquid (co-current) pipe flow behavior based on slug dynamics. In this study, the new model is validated with extensive experimental data acquired with different pipe diameters, inclination angles, fluid physical properties, gas-liquid flow rates and flow patterns. Good agreement is observed in every aspect of the two-phase pipe flow.

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