Patent ID: 6672406
Filing Date: 2004-01-06
Classification: E21B

Abstract:
A method of drilling subterranean formations comprising:providing a rotary drill bit including at least one cutting element thereon, the at least one cutting element including a longitudinal axis, a radially outermost sidewall, a superabrasive, multi-aggressive cutting face extending in two dimensions generally transverse to the longitudinal axis, the cutting face of the at least one cutting element including a first cutting surface oriented at a first angle with respect to a reference line adjacent the radially outermost sidewall and extending parallel to the longitudinal axis of the at least one cutting element, a second cutting surface adjacent the first cutting surface oriented at a second angle less than the first angle with respect to the reference line extending parallel to the longitudinal axis, and an additional, circumferentially extending chamfered surface positioned radially and axially intermediate the first cutting surface and the sidewall radially outermost of the superabrasive, multi-aggressive cutting face, the additional, circumferentially extending chamfered surface oriented at an angle less than the second angle of the second cutting surface of the superabrasive, multi-aggressive cutting face; drilling a relatively hard formation with the rotary drill bit by engaging primarily at least a portion of the first cutting surface of the superabrasive, multi-aggressive cutting face of the at least one cutting element with the relatively hard formation at a first depth-of-cut; and drilling a relatively soft formation with the rotary drill bit by engaging at least a portion of the second cutting surface of the superabrasive, multi-aggressive cutting face of the at least one cutting element with the relatively soft formation in addition to engaging at least a portion of the relatively soft formation with at least a portion of the first cutting surface of the superabrasive, multi-aggressive cutting face at a second depth-of-cut.