Systems and methods for analysis of drilling fluid

A drilling fluid analysis system, comprising:

• a drilling system, comprising:
• a drilling fluid tank;
• a pump;
• a wellbore line disposed in a wellbore and fluidly coupling the wellbore to the drilling fluid tank;
• and
• a fluid conduit fluidly coupling the wellbore to the pump;
• a capillary electrophoresis device disposed between the wellbore and the pump such that the pump moves a drilling fluid through the fluid conduit from the wellbore to the capillary electrophoresis device, from the capillary electrophoresis device to the pump, and from the pump to the wellbore, the capillary electrophoresis device configured to perform a first test on a first sample of the drilling fluid including an initial drilling fluid from the drilling fluid tank and a second test on a second sample of the drilling fluid including a return drilling fluid from the wellbore;
• and
• a processor configured to:
• analyze first results of the first test and second results of the second test to determine a characteristic of a subterranean formation, the characteristic based on a difference between a first concentration of reactive clay in the first sample and a second concentration of the reactive clay in the second sample;
• and
• provide an output based on the characteristic of the subterranean formation, the output comprising an amount of an inhibitor to add to the return drilling fluid and a time to add the inhibitor to the return drilling fluid.