Weatherford's Electric Submersible Pumping (ESP) Systems incorporate an electric motor and centrifugal pump unit run on a production string and connected back to the surface control mechanism and transformer via an electric power cable.The downhole components are normally suspended from the production tubing above the perforations. In a conventional system the motor and downhole monitoring tool are located on the bottom of the work string. Above the motor is the seal section, the intake or gas separator, and finally the pump, which is connected to the production tubing by the discharge head, which is basically a crossover from the ESP flange to the tubing thread. A specially designed flat cable (motor lead extension) connects to the motor at the upper pothead section, and is then spliced to a round or flat power cable above the ESP. This cable is then banded or clamped to the tubing all the way to the tubing hanger, where an electrical connection is made. A surface cable is then connected from this point to a junction box and finally to the Switchboard or VFD.

The Switchboard/VFD receives power from a utility grid or generator. When the ESP is started it draws the required voltage from this source. This powers the motor and thus generates pump rotation. As the fluid comes into the well through the perforations it passes by the motor and into the pump. This fluid flowing past the motor brings about a natural cooling process, critical for long and efficient motor life. The fluid then enters the intake and is taken into the pump. Each stage (impeller/diffuser combination) adds pressure or head to the fluid at a given rate. The fluid will build up enough pressure as it reaches the top of the pump to lift it to the surface and into the separator or flowline.