Study of Pulsation Pressures in the Stages of an Electric Submersible Pump at Shut-Off Under Various Speeds of Operation

2020 ◽  
Vol 13 (2) ◽  
pp. 171-183
Author(s):  
Arumugam Dhanasekaran ◽  
Sivasailam Kumaraswamy
Keyword(s):  
Pressure Pulsation ◽  
Pressure Fluctuations ◽  
Submersible Pump ◽  
Variable Frequency Drive ◽  
Prolonged Length ◽  
Unsteady Pressure ◽  
Discharge Valve ◽  
Closed Position ◽  
Valve Position ◽  
Electric Submersible Pump

Background: Electric Submersible Pumps (ESPs) are widely used in agricultural fields, petroleum, and various other industries. These pumps are mostly driven at a constant speed since an A.C. motor is normally used as the drive. However, ESPs can also be operated at various speeds by employing a Variable Frequency Drive (VFD). Several patents have been published in ESP. Normally these pumps are started with the discharge valve at its closed position in order to control the starting current. When the ESP runs at its shut-off position, it will develop a higher head and an increase in fluctuating pressure. In order to evaluate the effects of pressure fluctuation, its characteristics must be investigated. Objective: Experimentally investigate the characteristics of pressure pulsation which are generated at each stage of a multistage ESP during shut-off condition at various speeds. Methods: An ESP with five stages was selected for conducting experiments. A VFD was used for operating the ESP at five speed settings from 80 to 120 % of its rated speed. Piezoresistive transducer was placed at the delivery side of the pump to acquire the signals of unsteady pressure. The pump was operated at closed valve condition at each speed, and unsteady pressure signals due to pressure pulsation were captured. Results: Obtained results have indicated the presence of fundamental frequency pertaining to vane passing frequency and harmonics of higher frequencies. Conclusion: Study of pressure fluctuations at shut-off will help to analyze the failures of ESP due to vibration which occur when the pump runs at closed valve position for a prolonged length of time and stability of these pumps at lower flow rates.

Investigation of Pressure Pulsation in the Stages of an Electric Submersible Pump at Best Efficiency Point Under Various Speeds

2019 ◽  
Author(s):  
Dhanasekaran Arumugam ◽  
Kumaraswamy Sivasailam
Keyword(s):  
Pressure Pulsation ◽  
Maximum Amplitude ◽  
Operating Speed ◽  
Submersible Pump ◽  
Maintenance Activity ◽  
Total Head ◽  
Stage 4 ◽  
Return Channel ◽  
Diagnostic Measurement ◽  
Electric Submersible Pump

Abstract Fluctuating pressures can induce vibration in the Electric Submersible Pump (ESP) and severely affect the pump components. The installation depths of ESP systems are varying from a few meters to several hundred meters. Once installed ESPs are not accessible for diagnostic measurement and maintenance activity, so it becomes necessary to obtain detailed information of mean and fluctuating pressures to attain an optimal pressure distribution inside the pump. In this paper the results obtained from an experimental investigation of stage-wise pressure pulsation at Best Efficiency Points at various speeds are presented. Tests were conducted on a five stage ESP having impellers of 121 mm diameter and 14 mm width at outlet with impeller of 8 vanes and a diffuser-return channel of 6 vanes which delivers 7 lps (litres per second) and develop 60 m total head at various speeds. Unsteady pressure signals were captured by mounting piezoresistive transducers at each stage of ESP. Captured pressure signals were converted into frequency domain to analyze the characteristics of pressure pulsation. The results have indicated that the maximum amplitude of pressure pulsation was obtained at the highest operating speed setting of 60 Hz at stage 4. The normalized frequency at which this amplitude was maximum was highest at stage 2 at all the speeds.

Making smart wells equipped with electric submersible pump units

2018 ◽  
pp. 130-133
Author(s):  
S.S. Ulianov ◽  
◽  
R.I. Sagyndykov ◽  
D.S. Davydov ◽  
S.A. Nosov ◽  
...  
Keyword(s):  
Submersible Pump ◽  
Smart Wells ◽  
Electric Submersible Pump

Effects of the staggered blades on unsteady pressure pulsations and flow structures of a centrifugal pump

2021 ◽  
pp. 095765092098732
Author(s):  
Ning Zhang ◽  
Bo Gao ◽  
Chao Li ◽  
Dan Ni ◽  
Guoping Li
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Pulsation ◽  
Second Harmonic ◽  
Simulation Method ◽  
Pump Efficiency ◽  
Pressure Amplitude ◽  
Pressure Pulsations ◽  
Unsteady Pressure ◽  
Negative Effect

Effects of the staggered blades on unsteady pressure pulsations of a centrifugal pump with a specific speed ns=147 are investigated by the numerical simulation method. The obtained results are compared with the original blades. To clarify the resulting effects, eight monitoring points are used to extract pressure signals at three typical working conditions, and component at the blade passing frequency fBPF is emphasized. Results show that the pump efficiency and head will be reduced by the staggered blades, and at the nominal flow rate, the reduction is about 1.5% from comparison with the original blades. For all the eight points, the staggered blades contribute to the reduction of pressure amplitudes at fBPF when the pump works at three flow rates. The averaged reduction is 15.5% at the nominal flow rate. However, the negative effect on the second harmonic of fBPF will be caused by the staggered blades, and the corresponding pressure amplitude will increase at 2fBPF. It means that the pressure pulsation energy will be redistributed among the discrete components in pressure spectrum by the staggered blades. From the TKE distribution, it is found that the TKE values on the blade pressure side will be significantly affected by the staggered blades.

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