1. n. [Drilling Fluids]

A mud that slows or stops hydration, swelling and disintegration of shales. A variety of mud types have been labeled as "inhibitive muds." The degree of inhibition is not quantitative, but qualitatively they range from highly inhibitive (balanced-activity oil muds), moderately inhibitive (potassium muds and silicate muds), fairly inhibitive (calcium-based fluids) to slightly inhibitive (lignosulfonate, lignite water muds) to non-inhibitive (freshwater, nontreated muds).

See: balanced-activity oil mud,  calcium mud,  clay,  clay-water interaction,  drilling fluid,  hydration,  inhibit,  lignosulfonate,  oil mud,  potassium mud,  shale,  silicate mud