BENTONITE viscosifier is a finely ground, premium-grade bentonite meets API standards that yield 100 bbls of 15- cp mud per ton (16 m3/ton). It is used in water-based drilling fluids as filter cake building, filtration control and suspension. As with all bentonite products, the yield decreases as water salinity increases. In muds containing more than 10,000 ppm chlorides, the performance of BENTONITE is significantly reduced unless pre-hydrated in freshwater before adding to the mud system.