tubing leaking

[MOSTAFA86]

Dear jents

I have a question about tubing leaking in Esp systems,, I want know what is the affect of tubing leaking on motor amp (running amp)as I read on some papers that it Dec the amp,and which I think not correct, any help please.

Second thing,

 

[LittleInch]

It kind of depends - If the leak has a bigger impact on head loss than extra flow it might go down, but if it is big enough then more flow will generally equate to more amps. Really need to look at the pump curve and system pressures / head to see which would apply depending on the impact of the hole.

second thing???

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[MOSTAFA86]

Sure it affect on production,, I have low flow with decrease in discharge pressure,low whp,and increase in chp and increase in intake pressure.,so if I have big hole it will take more amp!?

 

[zdas04]

It really depends on where the hole is. Motor hp is a function of how much stuff you are lifting AND how far you are lifting it. A moderate hole in the pump-outlet threads will steal a lot of flow, but at low pump head so amps will go down. A huge hole at the tubing hanger will steal a lot of flow, but it has been pumped the length of the tubing so amps will go up. Most holes are somewhere in between. A moderate sized hole in the middle of the tubing may have the same amp draw as no leak at all. You can use motor amps IN CONJUNCTION with the pump curve, surface pressure, and flow rate to guess where the leak might be and how big it might be, but it is just a guess. By themselves, none of these parameters mean much in isolation.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. ùGalileo Galilei, Italian Physicist

 

[d23]

MOSTAFA86
Look at your pump curve. How much power did it require when it was operating correctly? Using the curve how much power would it require at the maximum flow rate plotted on the curve? This will tell you if the power should go up or down with a tubing leak.

Below are general descriptions of power required based on stage geometry. Remember the size of an impeller designed for an ESP is limited by casing size. Stages used in ESP’s are typically designed a little different than stages used in the industrial pump industry due to the physical space limitations.

1.Radial flow stage power will continue to increase as flow increases.

2.Mixed flow stage power requirements are reasonably flat. For electrical submersible pumps a mixed flow stage will start with a low power requirement at low flow rates and increase to its maximum requirement around the pump BEP. It will then start to decrease as flow increases above BEP.

3.Axial flow stage (gas pumps) power is highest at 0 flow and decreases as flow increases.

 

[MOSTAFA86]

Thx gents for all your help it really helped me alot,,but i have another question so thanks for your patient

overload and under load setting and its time delay.

some engineers use to set over load on 115% of running amp, some set it one 115% of rated motor amp,,with start delay zero seconds and run delay between 4 to 8 seconds.

for underload ,its common of 85 to 80 % of running ampere with long start ( 10 seconds )and run delay (30 sec ).

my question is what is the ideal setting for overload and underload values and its time delay and why ,,thx again for ur help

 

[LittleInch]

You're best off starting a new thread in the electrical forum. There are guys there who will know this instantly

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way