1. n. [Drilling Fluids]

The addition of a mud product to fresh water prior to adding it into the mud system. Bentonite clay and XC polymers are two additives whose performance improves by hydration in fresh water before adding them to a highly-treated or salty mud system.

See: bentonite,  clay-water interaction,  colloid,  hardness ion,  hydration,  hygroscopic,  prehydrated bentonite,  soft water,  XC polymer