Method and apparatus to control water migration into electrical submersible pump motors

An electrical submersible pump assembly disposable within a wellbore comprising:

• a housing;
• a motor;
• a pump coupled to the motor by a shaft;
• a seal section comprising a flexible bladder with an outer surface in pressure communication with pressure ambient to the housing and an inner surface in pressure communication with the motor;
• and
• a moisture absorbing material disposed in the seal section for absorbing moisture in the seal section.

A method of pumping fluid from a wellbore comprising:

• a. providing a submersible pumping system comprising a motor, a pump coupled with the motor, a seal section for equalizing pressure in the motor with pressure ambient to the motor, and dielectric fluid in the seal, in the motor, and in a passage extending between the seal and the motor;
• and
• b. providing a moisture absorbing material in the dielectric fluid and in a location that is in an expected path of moisture flow from ambient to the housing and to the motor, so that when wellbore fluid from the wellbore leaks into the dielectric fluid, moisture in the wellbore fluid is absorbed in the moisture absorbing material;
• and
• c. inserting the submersible pumping system into the wellbore and activating the motor to operate the pump.