When operated in a well, boring graphite: Creates a positive pressure to interstitial pressure; - transfers hydraulic power to the bottom hole motor and chisel; - provides a high quality producing formation exposing; - ensures lubricating and corrosion-inhibiting effect on drilling tools; - cools and lubricates a chisel; - prevents drilling troubles (sticking of drilling tools and intermediate casing, circulation loss, oil and gas shows, etc.); - reduces friction factor; - ensures environment protection; 1.Bulk density, kg/m3550 - 750 2.Moisture content, % max2 3.Ash mass fraction, % max25 4.Mesh residue 02, % max5