1. n. [Drilling Fluids]
A chemical additive that creates an emulsion, a dispersion of one immiscible liquid into another, by reducing the interfacial tension between the two liquids to achieve stability.
Two emulsion types are used as muds:
The former is classified as a water-base mud, and the latter as an oil-base mud.
See: coalescence, creaming, dispersant, fatty acid, fatty-acid soap, interfacial tension, invert-emulsion oil mud, oil-mud emulsifier, surface tension, surfactant, water-mud emulsifier