http://www.unitechzibo.com/polyanionic-cellulose/
Polyanionic Cellulose, shortly PAC are used in oil drilling fluids and completion fluids. In drilling fluids, it works as viscosifier, flowing controller and filtration reducer, with strong suspending capability, high ability of carrying crumbs, and the function of cleaning drilling crumbs, stabilizing of well wall, preventing the mud from flowing away, protecting drilling bit and reducing the thickness of mud cake, but while in the completion fluids, it functions to control the fluid viscosity, suspend the heavy objects, bring the filler and avoid the fluids loss.