1. n. [Drilling Fluids]

A dispersion of oil droplets into an aqueous medium. This describes an emulsion mud, as contrasted with an invert-emulsion mud. The term should not be used to refer to synthetic-in-water emulsion because a synthetic fluid is not a true oil.

See: demulsifier,  emulsion mud,  hydrophile-lipophile balance number,  invert-emulsion oil mud,  syn