Modeling Oscillatory Behavior of Electrical Submersible Pump Wells Under Two-Phase Flow Conditions

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Rinaldo Antonio de Melo Vieira ◽  
Mauricio Gargaglione Prado

The effect of free gas on electrical submersible pump (ESP) performance is well known. At a constant rotational speed and constant liquid flow rate, a small amount of gas causes a mild head reduction when compared to the single phase liquid head. However, at higher gas rates, a drastic reduction in the head is observed. This critical condition, known as the surging point, is a combination of liquid and gas flow rates that cause a maximum in the head performance curve. The first derivative of the head with respect to the liquid flow rate changes sign as the liquid flow rate crosses the surging point. In several works on ESP two-phase flow performance, production conditions to the left of the surging region are described or reported as unstable operational conditions. This paper reviews basic concepts on stability of dynamical systems and shows through simulation that ESP oscillatory behavior may result from two-phase flow conditions. A specific drift flux computation code was developed to simulate the dynamic behavior of ESP wells producing without packers.

Author(s):  
Rinaldo Antonio de Melo Vieira ◽  
Mauricio Gargaglione Prado

The effect of free gas on the Electrical Submersible Pump (ESP) performance is well known. At a constant rotational speed and constant liquid flowrate, small amount of gas causes a mild head reduction when compared to the single phase liquid head. However, at higher gas rates, a drastic reduction in the head is observed. This critical condition, known as surging point, is a combination of liquid and gas flow rates that cause a maximum in the head performance curve. The first derivative of the head with respect to the liquid flow rate change sign as the liquid flow rate crosses the surging point. In several works on ESP two-phase flow performance, production conditions to the left of the surging region are described or reported as unstable operational conditions. This paper reviews basic concepts on stability of dynamical systems and shows through simulation that ESP oscillatory behavior may result from two-phase flow conditions. A specific drift flux computation code was developed to simulate the dynamic behavior of ESP wells producing without packer.


2011 ◽  
Vol 383-390 ◽  
pp. 4922-4927
Author(s):  
Peng Xia Xu ◽  
Yan Feng Geng

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.


Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 388
Author(s):  
Juanli Zuo ◽  
Fengchao Li ◽  
Ning Zhang ◽  
Denghui He ◽  
Wen Wang ◽  
...  

A pneumatic lifting pump is used in sewage treatment, offshore oil production, and other fields because of its simple structure and strong practicability. In order to study its internal hydraulic characteristics and gas-liquid two-phase flow, this paper carries out experimental research on the influence of different air intake modes and riser diameters on the performance of a pneumatic lifting pump. The air-water two-phase flow pattern in the riser and motion characteristics of bubble formation at the nozzle are obtained by a high-speed camera. Through theoretical analysis, the theoretical model of a pneumatic lifting pump is established, and experimental results verify the theoretical model well. The results show that when the submergence ratio is constant, the lifting efficiency decreases with the smaller intake area under different intake areas; and the influences of different holes distributions on liquid flow rate and lifting efficiency are not significant under the same intake area. At the same submergence ratio, the smaller the riser diameter, the smaller the final lifting liquid flow rate and the larger the lifting efficiency peak value.


Author(s):  
Hideo Ide ◽  
Ryuji Kimura ◽  
Masahiro Kawaji

An optical measurement system was used to investigate the effect of microchannel length on the characteristics of adiabatic gas-liquid two-phase flow. Experiments were conducted with a 1,676 mm long, circular microchannel with an inner diameter of 100 μm. Two-phase flow patterns, void fraction and velocities of gas plug/slug and liquid slugs were measured at different locations between the gas-liquid mixer and channel exit. The experimental values of the mean void fraction and the mean velocity of liquid slug agreed well with the homogeneous flow model predictions when the liquid flow rate was constant and the mass velocity of the gas was low. The flow pattern transition from slug flow to ring film flow was observed when the mass velocity of the gas was increased while the liquid flow rate was kept constant.


2021 ◽  
Vol 16 ◽  
pp. 158-167
Author(s):  
Abdulqader Hasan ◽  
Mohamed S. Gadala ◽  
Salman Shahid ◽  
Mohd Shiraz Aris ◽  
Sharul Sham Dol ◽  
...  

The effects of the wall shear stress on an Electrical Submersible Pump (ESP) was investigated in this paper. A CFD model in ANSYS Fluent was proposed to simulate actual single-phase and two-phase flow. The bottom hole pressure was minimized by utilizing the artificial lift methods. The flowing fluids in pumps and pipes causes shear stress on surface interacting. In multiphase flow application pump damages on head degradation as well as shear stress affects. The K-ω turbulence model and the multiphase Mixture approach with the sliding technique used to solve the Navier-Stokes equation. To study the effects of gas-liquid (air-water) flow on the ESP and the pump handle ability, the rotation speeds were varied while the other parameters were kept constant. The rotation speeds simulated were at 500, 900, 1500, 2000 and 2500 rpm meanwhile the water flow rate and gas flow rate were kept constant with 20 L/min and 1% fraction, respectively. The results obtained show that as the rotation speeds were increased, the less concentration of the bubbles were observed, moreover the wall shear stress (WSS) increases. Although, the wall shear stress in both single-phase and two-phase flow were tend to increase as the blades length increased, however for the single-phase flow the WSS was found higher in all the simulated rotational speeds.


Author(s):  
Olufemi E. Bamidele ◽  
Wael H. Ahmed ◽  
Marwan Hassan

The current work studies air-water flow through a ½-inch flow restricting orifice installed in a 1-inch pipe. Investigation of two phase flow downstream the orifice and its effects on vibration of the piping structure have been carried out. Several flow regimes from bubbly to stratified-wavy flow have been analyzed to evaluate the effects of flow pattern, phase redistribution, bubble frequency, and liquid flow rate on the vibration of the structure. The liquid velocity fields have been obtained using Particle Image Velocimetry (PIV) along with post processing algorithm for phase discrimination. Proximity sensors have been used to capture the pipe response in two orthogonal directions. Also, a capacitance sensor was used to measure the two-phase void fraction. The results show that the magnitude and nature of vibrations of the piping structure is largely affected by the frequency and size of the bubbles upstream, vortex creation by pressure fluctuation downstream, liquid flow rate, and the flow pattern upstream. Slug flow and stratified flow patterns induced significant vibrations in the examined structure. The location of the transition region of slug flow on flow pattern maps, play important role in the dynamic response of the structure to the flow.


1970 ◽  
Vol 92 (4) ◽  
pp. 587-594 ◽  
Author(s):  
R. Farmer ◽  
P. Griffith ◽  
W. M. Rohsenow

Two-phase annular flow deposition was studied. Experiments were performed to determine where small water droplets in an air stream in a round tube would reach the wall. Results indicated that, for fully accelerated droplets whose diameters were within a factor of two of 150 microns, the number reaching the wall was characteristic of exponential decay with distance downstream. Further, the mean free path to the wall, measured axially, could be taken proportional to droplet diameter. With the assumption that dispersed liquid flow rate in annular two-phase flow regimes consists chiefly of droplets traveling at or near gas velocity, and with arbitrary choices of droplet, diameter spectrum and magnitude of entrainment rate, it was possible to derive analytical expressions for mass transfer coefficient, deposition flow rate, dispersed liquid flow rate, mean diameter and spectrum as they all changed downstream. Some experimental measurements by others were successfully reproduced by these expressions. An important result was that droplet size spectrum “hardening” (preferential depletion of small sizes) operates to decrease the deposition rate downstream, especially if there is no longer any entrainment.


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