Drill bit with improved insert cutter pattern and method of drilling

In a drill bit utilizing a plurality of polycrystalline diamond cutting elements having midpoints axially spaced away from the face of the body of the bit at least one preselected distance and with the cutting edges of the elements defining a predetermined radially extending profile relative to the face when the bit is rotated about its axis, the improvement comprising the arrangement of said cutting elements on the face of the bit body in first and second adjacent groups with the midpoints of said elements in each of said groups spaced angularly from each other and radially from the midpoints of the elements in the other group whereby the rotated radial profiles of said cutting edges in said first group do not radially overlap the profiles of the cutting edges of said elements in said second group by a cumulative maximum amount measured in the axial direction which is substantially more than the cumulative axial lengths of either one of the cutting elements whose cutting edges overlap, and wherein said cutting edges of the elements in both of said groups each includes an axially directed portion extending away from the face of said bit body and not overlapped with the cutting edges of the elements in the adjacent group, said axially directed portions of each cutting edge extending away from both the face of the bit and the midpoint of its element a distance of sufficient axial length for said cutting edges to cut into formation material when drilling to form at least one concentric ridge of formation material having an apex portion which is removed and a base portion which is maintained between said first and second groups of cutting elements during drilling with said ridge having a height sufficient to keep said drill bit from moving in a lateral direction.