An ESP looks simple from surface — a cable disappearing down a well — but downhole it is a carefully balanced system. Understanding how the pieces work together is the key to specifying, operating and troubleshooting one effectively.
Power from surface to motor
Electricity travels from the surface controller down the armoured power cable to the ESP motor. The cable must carry the required current at downhole temperature with an acceptable voltage drop over the full setting depth — an often-overlooked part of the design.
The motor turns the pump
The downhole motor is a two-pole induction motor filled with dielectric oil and cooled by the fluid flowing past it. It converts electrical energy into the rotation that drives the pump shaft above it.
Multistage centrifugal lift
The pump itself is built from many stages, each a rotating impeller and a stationary diffuser. Each stage adds a increment of head; stacked in series, dozens or hundreds of stages generate the total lift needed to raise fluid to surface. This is why precision-machined, well-matched stages matter so much to efficiency.
The seal section protects the motor
Between motor and pump sits the seal or protector section. It equalises pressure, absorbs the axial thrust the pump generates, and — critically — keeps well fluid out of the motor. Seal failure is a common route to motor failure.
Handling gas and solids
Where free gas or sand is present, a separator or gas-handling stage is added at the intake to protect the pump. Managing these before they reach the stages is far more effective than trying to pump through them.
Fiastar manufactures the precision components that keep this system running in challenging wells. Share your well conditions and our team will respond within one business day.