Efficiency Evaluation and Improvement of Deep Well Submercible Pumps

Are these positive displacement pumps or centrifugal pumps? What is the temperature, nature and viscosity of the fluid pumped? Up-hole temperature drop?

These are centrifugal pumps, water pumps and temperature is 33 deg-C. Not aware of temperature drop along lift, but I feel there is pick up additional heat, since the ambient temp soars as high as 50 deg C. I am realising the KSB and Ritz companies indicate a design efficiency at 20 de C.

There are other specialist considerations that you also need to consider.

The relative altitude of each well head will affect the apparent head if they are pumping into a common rising main (header). (one that is 10m higher up the hill will seem to have a discharge pressure 10m lower than anequivalent one at the lower height.)

Do you have output flowmeters on each pump/well?

Do you have power monitoring on each pump/well?

Only withthese will you be able to determine the "efficiency" of each pump individually.

Note that efficiency and yield may not be matched.

Also, the pump that has the furthest length of pipe to push through will have varying efficiency based on the line friction caused by the other pumps running (or not).

You have a complex multiparameter problem that requires specific site analysis. You seem to be asking the right sort of questions, you now just need to find an expert who can review your specific situation,

I agree the mention that it requires site analyis since it is complex. Your answers/opinion has been very good, giving me some thoughts first time.

There are flow meters, manometers and power is computed from Volt/amp. I noe that specialists are to be contacted or manufacturers. Since efficiency is an issue difficult to compare and relate, one suggestion that Wh consumption per meter-water column pumped is a reference. This is seen to be around 3.8 to 4.5 WH/meter Water column. Are there any references to this data by anyone?.

First... how deep is deep?

What is your TDH?

Who made the ESP... electrical submersible pump?

Multi-stage or single stage pumps?

What are you pumping? (already asked I know) the SP of the fluid is important!

Do you have a downhole gauge fixed to the bottom of the motor?

What size of tubing or piping to surface?

You are looking for efficiency improvement for the systems if I'm not mistaken?

you said.. age varying from 2-15 years

The pumps older than 5 years will not be efficient as they will have worn impellers due to the sand, grit and solids they will have pumped to the surface, so your efficiency is gone. If you are looking for higher efficiency then I would recommend replacing these pumps. However you have to weight up the cost of replacement against the cost of producing fluid at this present time. You just might find it would be better to let the pump run until it fails. So what is your MTBF?

The efficiency of your pump is a given at point of purchase and it will not get any higher, you might be lucky to get 70% efficiency, and that's for a NEW pump.

If you are looking to improve the system in regards to power consumed, as you mentioned "Frequency variation', do you mean a Variable Speed Drive (VSD)"? Power consumed verses fluid produced is a tricky one. Maybe if you went back to the supplier of the pumps, they should be able to help you with an overall system improvement. VSD's if you buy the wrong one will add to your problems rather than reduce the problems. You say you switch the pumps on and off? How often? ESP's don't like being turned on and off, the advantage with a VSD is you get a soft start, which reduces the in-rush current and mechanical load on the pump when starting.

There are so many variables in what you are asking, and my best advice is to talk to your pump vendor and ask for advice. Remember, they need to keep customers these days, so he should jump to it. If he doesn't then go look for another vendor, there is always someone willing and able to give you exactly what you need

FYI.. before I forget.. if you do have a ESP, and the motor is on the bottom, it is the fluid passing over the motor that keeps the motor cool, and then you have the mechanical pumping action on the fluid which also heats up the fluid, so you will get a fluid temperature increase at surface.

Tks for your point-wise brief and query.I am replying as below.

.. how deep is deep? It is 300 Meters deep.

Who made the ESP... electrical submersible pump? RITZ and KSB-Germany.

Multi-stage or single stage pumps?-9 stage

What are you pumping? (already asked I know) the SP of the fluid is important! Water

Do you have a downhole gauge fixed to the bottom of the motor?--Manometer

What size of tubing or piping to surface?-12 inches bore

You are looking for efficiency improvement for the systems if I'm not mistaken?-

Ans: Yes-Reduced cost of pumping water. There are suppliers of SCADA-who want to bring in SCADA and monitor/operate with advanced analytics-and bring in 15% savings w/o replacing the worn out impeller/asset (as you mentioned) with high efficiency/new ones

you said.. age varying from 2-15 years-

Yes (There are 60 pumps in operation totaling around 360 Million Liters/day)

The pumps older than 5 years will not be efficient as they will have worn impellers due to the sand, grit and solids they will have pumped to the surface, so your efficiency is gone. If you are looking for higher efficiency then I would recommend replacing these pumps. However you have to weight up the cost of replacement against the cost of producing fluid at this present time. You just might find it would be better to let the pump run until it fails. So what is your MTBF?-

Ans:This is a very strongly supportive statement and thanx. However, is there a way to term through - KWH/cub.meter and Costs of pumping by refering to standard/benchmark consumption. I did find for surface water pumping as 3 to 4 KWh/cub. Meter pumped depending on elevation-of course.

The efficiency of your pump is a given at point of purchase and it will not get any higher, you might be lucky to get 70% efficiency, and that's for a NEW pump.

You have supplied very Good information concerning VFD, fluid temperature etc.

We install Inverters(VFD) and they save 35+% electricity.

do you use IEEE rated drives on the line side and Harmonic filters on the output?

What is the application?