Patent ID: 6296069
Filing Date: 2001-10-02
Classification: E21B

Abstract:
A drill bit for well drilling, comprising:a central body, said central body having a front area in a direction of drilling and a side area in a direction laterally away from a central axis of the bit rotation,cutting blades protruding from the front area and side area of said body, said cutting blades having front external surfaces on the blades protruding from the front area of said body and side external surfaces on the blades protruding from the side area of said body,cutting elements disposed over the external surfaces of said blades,at least one synthetic polycrystalline diamond compact cutting disc disposed in a central area of the front external surfaces of said blades, said central area being coaxial with said central axis of the bit rotation, andthermally stable synthetic diamonds and impregnated diamond particles disposed on a remaining area of the front external surfaces of said blades outside said central area characterized in that said remaining area of said front external surfaces is divided into first and second coaxial circular areas that are coaxial with said central area and wherein said first coaxial circular area is provided with cutters comprised of the thermally stable synthetic diamonds and said second coaxial circular area is provided with cutters comprised of the impregnated diamond particles.