Patent ID: 6422327
Filing Date: 2002-07-23
Classification: E21B

Abstract:
A drill bit for cutting a formation, comprising:a bit body having a bit axis; a plurality of rolling cone cutters rotatably mounted on cantilevered bearing shafts on said bit body, each rolling cone cutter having a generally conical surface; a plurality of gage row primary cutter elements extending from one of said cone cutters in a gage row, said gage row extending to full gage; a first plurality of primary cutter elements extending from a first of said cone cutters in a first row, said first row extending to less than full gage; a second plurality of primary cutter elements extending from a second cone cutter in a second row, said second row extending to less than full gage, said second primary cutter elements overlapping said first primary cutter elements when revolved into a single plane; and at least one ridge-cutting cutter element positioned between said first and second rows of primary cutter elements; wherein at least one rolling cone cutter includes a land surrounding at least one row of said prim ary cutter elements and a groove adjacent said land, and at least one of said ridge-cutting cutter elements is at least partially positioned in said groove.