Patent ID: 8641389

Claim:
An electrical submersible pump (ESP) assembly comprising: a pump section having a pump; a motor section having a motor that is coupled to the pump with a shaft; and a seal section between the pump section and the motor section comprising: a housing; an annular guide tube circumscribing the shaft in fluid communication with an annular space between the housing and the annular guide tube through a port in a sidewall of the annular guide tube disposed proximate the pump section; a bore formed axially through a sidewall of the annular guide tube in communication with a fluid ambient to the ESP assembly and in fluid communication with the annular space through an exit port disposed proximate the motor section, so that when the ESP assembly is disposed in a wellbore having a wellbore fluid, and the annular space is filled with a lubricating fluid, a labyrinth path is defined that extends from outside of the ESP assembly downward through the bore, upward through the annular space, and downward through an inner annulus between the annular guide tube and the shaft to the motor section.