Patent ID: 7762355

Claim:
A rotary drag bit, comprising: a bit body with a face and an axis; at least one blade extending radially and longitudinally over the face; a primary cutter row comprising at least one primary cutter, the at least one primary cutter including a cutting surface protruding at least partially from the at least one blade, located to traverse a cutting path upon rotation of the bit body about the axis, and configured to engage a formation upon movement along the cutting path; and a backup cutter group comprising a first trailing cutter row and a second trailing cutter row, each trailing cutter row comprising at least one cutter including a cutter configuration and a cutting surface protruding at least partially from the at least one blade, the at least one cutter of each of the first and second trailing cutter rows positioned so as to substantially follow the at least one primary cutter along the cutting path upon rotation of the bit body about its axis, and each cutter configured to selectively engage the formation upon movement along the cutting path; and wherein the cutter configuration of the at least one cutter of the first trailing cutter row is oriented at least one of: a different backrake angle from a backrake angle of the at least one cutter of the second trailing cutter row; and a different siderake angle from a siderake angle of the at least one cutter of the second trailing cutter row.