1. n. [Drilling Fluids]

A copolymer of vinyl acetate (ethylenic polymer) and anhydrous maleic acid (a di-hydroxy acid). The vinyl acetate polymer component is usually high molecular weight. As such, with polar groups on the structure, it is used as a flocculant or bentonite extender.

Alternate Form: VAMA

See related terms: clay extender,  clay-water interaction,  closed mud system,  polar,  vinyl polymer,  wastewater cleanup