ESP Troubleshooting

[High_Volt]

Hi Everyone,
I have a case with an ESP where its tripping due to U/L. But after the ESP trip, Pd dropped less than Pi.
Can you please inform about this situation?

Note: ESP is installed in High gas well.
Many Thanks,

 

[sraesttam]

If the set points are correct, the ESP went down on underload because it is not moving enough fluid through the pump.
What are the intake and discharge pressures? Are you on a drive? Do you have any check valves installed in the tubing above the pump?
How long after the pump shut down did you take the pressure readings?

 

[High_Volt]

Hello,

yes its running of VSD and after the trip Pi was stabilizing at 934 psi and Pd dropped down to 518 psi which makes me surprised.
There is already check valves but on the surface flowline not on the D/H production tubing. the Pd dropped lower than Pi within 12 minutes only.

Many Thanks in advance.

 

[zdas04]

ESP is a dynamic pump, not positive displacement. It only works above some minimum Reynolds Number. What is the flow rate through the pump when it is running? Where are the suction and discharge gauges? Please don't tell us that the casing pressure is the "Pi" and the tubing pressure is the "Pd". Please don't.

[bold]David Simpson, PE[/bold]
MuleShoe Engineering

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

 

[High_Volt]

Hello,

Well, the ESP was installed in a high gas well.
Pi is the pressure obtained by the sensor for the ESP pump intake pressure and Pd is the discharge pressure at the pump discharge.
so Pi supposed to be at the bottom and Pd is at the top of ESP inside the tubing.
Regarding the flowrate, its known to be low flow well (280 bpd) with high gas value.

Regards,

 

[sraesttam]

When the underload trip occurs, touch the tubing with your hand. Does it start getting cold and can you hear gas expanding and liquid slugging? Your well may be flowing up the tubing naturally after the pump turns off. The pumps are causing a pressure drop since they are no longer spinning which also explains how your discharge pressure is lower than your intake pressure.

I don't think something is wired wrong down hole, but sometimes registers get mapped to the wrong place on SCADA surface readout. When the well is pumping, grab a wrench and add more back pressure to your tubing for a couple of minutes and make sure that your discharge pressure actually increases. This way you have more confidence that the discharge pressure reading is actually telling you the discharge pressure and that the two pressure values didn't get accidentally swapped.

 

[High_Volt]

Many thanks for the tips. Unfortunately the ESP failed before carrying out a production testing to know whats going on exactly.
It will be scheduled for dismantle job when its pulled out.

Thank you all for your support.

 

[moredrilling]

Hello
Did you figure out what was wrong with your ESP? I have a situation where the intake pressure has increased much higher than the tubing pressure, and production declined by about 500 bbls/d. There is evidence of CaSO4 scaling. I am guessing scaling in the tubing is responsible for the pressure increase and that the ESP should be fine. They are about to pull the ESP. Replacing it will be costly for a marginal well.

 

[High_Volt]

Hi,
Sorry to hear that but we still didnt pull this ESP due to priorities... you know.
I will share the findings once we pull it and dismantle it.

Thanks,