The production rate, useful life and operating efficiency of electric
submergible pumping systems (ESP) is improved by operating the system so
that the motor (220, 320) is cooled by two passes of production.
Production fluids remove waste heat from the motor (220, 320) by passing
the fluid in contact with the exterior of the motor (220, 320). The
improved cooling permits the motor to be operated at a lower temperature
improving life and efficiency, and/or to be operated at higher power at a
similar temperature. Additionally, oversized and excess equipment is not
required, further improving performance and economics for the user. In
another aspect, the invention is a method of pumping fluids using a motor
having vortex generators (366) on its exterior surfaces or on the
interior surfaces of a surrounding shroud.