Drilling Grade Bentonite is the main component of water based drilling fluid, which is a vital element of drilling process. Bentonite is used as a mud constituent for oil and water well drilling. Its roles are mainly to seal the borehole walls, to remove drill cuttings and to lubricate the cutting head. Bentonite has high swelling and good colloidal nature, which can increase the viscosity of suspension in the drilling mud and also can increase the lubrication of drilling, as well as for the rig-freeing agent.