Patent ID: 6135218
Filing Date: 2000-10-24
Classification: E21B

Abstract:
A fixed cutter earth boring bit comprising a steel bit body with upper and lower ends, the upper end of the bit body adapted to be secured to a drilling string, a cutting face formed on the lower end of the bit body, and passaging within the bit body to receive pressurized drilling fluid from the drilling string,an orifice on the cutting face in fluid communication with the passaging in the bit body to receive the pressurized drilling fluid, the orifice adapted to accelerate the pressurized drilling fluid,at least one superhard cutting element fixed upon the cutting face to engage the earth and effect a drilling action, and,an erosion and abrasion resistant overlay on a portion of the cutting face, the overlay comprising a hard material particulate containing a metal carbide and an alloy steel matrix, wherein the volume fraction of the hard material particulate in said overlay is greater than about 75%, the average particle size of the hard material particulate is between about 40 mesh and about 80 mesh, and the thickness of the overlay is less than about 0.050 inches.