HOW CAN I SELECT A ELECTRIC MOTOR FOR A PCP PUMP?

[neca]

Hi,
I would like to get some information about how to select the right electric motor for an oil pcp pump aplication.
( Progressive Cavity Pump )

Bets Regard,
Neca

 

[smckennz]

Hi Neca
It makes me puke to say this, but check with the manufacturer. The reason is that the friction loss by the slipper shoe and the pipe crush loss are not easily calculated. For a small pump (say 2" hose or less), the losses could be larger than the usefully transmitted power.
If you do not have access to the manufacturer, send me the following details and I will give you an estimate if I can:
Hose diameter
Hose wall thickness, construction and material
Hose bend centreline radius
Gearbox reduction ratio
Description of shoe/hose lube system
Desired pumped fluid properties (name, density, temperature, viscosity, contaminants)
Gerabox style and reduction ratio

Cheers

Steve

 

[smckennz]

And I forgot
flow/tdh/pressure
number of rollers/slippers

cheers

Steve

 

[yimc]

Hi Neca

You didn't say if this was for downhole or not. Assuming it is;

1) Weatherford and others have software to determine the proper e-motor requirements for your application.

2) There is a couple of quick and dirty calculations you can do:

Torque = [total net lift * displacement (m3/100) /125] + 100 (this is for pump friction)

Then: HP = Torque * rpm /5252

Normally, you would add about 20% additional horsepower for startup torque issues. Not exact, but will get you in the ballpark.