AQUAVIS®HT viscosifier is purified hectorite clay that impacts thixotropy and good anti-settling properties to high temperature water-based drilling fluids. AQUAVIS®HT is stable at temperatures of up to 400°F. Unlike most conventional synthetic polymers, AQUAVIS®HT exhibits an excellent rheological profile with elevated low-end readings essential for hole cleaning in directional drilling and coiled tubing operations. The additive is compatible with most oilfields'brines. However, as brines approach saturation, efficiency may be compromised. Pilot test for higher-salinity brine impacts is required.