Oil Drilling Grade Sodium Carboxymethyl Cellulose is a type of water-soluble polymer that is used as a viscosifier, fluid loss reducer, and shale inhibitor in oil and gas drilling fluids. It is extensively used to improve the rheological properties of the drilling fluid, such as viscosity, fluid loss, and gel strength. This also helps to prevent the hydration and swelling of shale formations, which can cause stability problems during drilling. Moreover, the Oil Drilling Grade Sodium Carboxymethyl Cellulose generally considered safe for use in oil and gas drilling fluids by regulatory agencies such as the FDA and EPA.