1. n. [Drilling Fluids]

Water added to maintain or dilute a water-mud system. The added water may be fresh water, seawater or salt water, as appropriate for the mud. Make-up water volume is an important parameter in a material balance check on solids content and solids removal efficiency for a mud system. The amount of dilution strongly influences mud economics. If soft make-up water is needed, treatments to remove hardness ions should be done prior to adding the water to the mud to avoid clay flocculation and polymer precipitation.

Synonyms: dilution water

See: calcium test,  chloride test,  clay-water interaction,  hard water,  hardness ion,  material-balance equation,  native-solids mud,  peptized clay,  seawater mud,  total hardness test