Increasing the rate of penetration of drill bits without increasing the weight on the bit or the torque would increase drilling efficiency and lower drilling costs. However, the rate of penetration (ROP) of drilling tools is limited by the force needed for domed percussion cutters to penetrate into the rock. Polycrystalline diamond coatings have already improved cutter wear characteristics, but they have not been investigated as a method to decrease the cutting forces required for domed percussion cutters. If polycrystalline diamond coatings were highly polished, rock-cutter friction and penetration force would be reduced, and ROP increased. In Phase I, new polishing techniques for polycrystalline diamond coatings on domed cutters will be used to lower the coefficient of friction and the force required to penetrate rock. Phase II will optimize ultra-low coefficient of friction domed bit cutters for percussion drills for high ROP in different rock types. The degree of polish, the PCD coating, tile cutter placement, size, radius, and shape will be optimized.
Commercial Applications and Other Benefits as described by the awardee:A new generation of diamond enhancement products for drill bits should increase the usefulness of diamond insert technology by lowering the drilling resistance of rock. Because less force is required to penetrate the rock and the coefficient of friction is reduced, bit life should be increased.
