Shoulder durability enhancement for a PDC drill bit using secondary and tertiary cutting elements

摘要

A PDC bit includes a plurality of blades. A blade includes a primary cutter row and a secondary cutter row. Primary PDC cutters on the primary cutter row are set in accordance with a single set methodology. Backup PDC cutters on the secondary cutter row are set in accordance with a methodology wherein a radial position of each backup PDC cutter in the secondary cutter row is offset from a radial position of each primary PDC cutter in the primary cutter row. The blade further includes a tertiary cutter row. Additional backup PDC cutters on the tertiary cutter row are set in accordance with a methodology wherein a radial position of each additional backup PDC cutter in the tertiary cutter row is offset from a radial position of each primary PDC cutter in the primary cutter row. The backup cutter setting methodology is effectively radially positions the included backup PDC cutters (in the secondary cutter row and/or tertiary cutter row) between primary PDC cutters in the primary cutter row.