DRILL BIT HAVING STABILITY ENHANCING CUTTING STRUCTURE

摘要

A fixed cutter drill bit includes a cutting structure having radially-spaced sets of cutter elements. The cutter element sets preferably overlap in rotated profile and include at least one low profile cutter element and at least two high profile elements. The low profile element is mounted so as to have a relatively low exposure height. The high profile elements are mounted at exposure heights that are greater than the exposure height of the low profile element, and are radially spaced from the low profile element on the bit face. The high profile elements may be mounted at the same radial position but at differing exposure heights, or may be mounted at the same exposure heights but at different radial positions relative to the bit axis. Providing this arrangement of low and high profile cutter elements tends to increase the bit's ability to resist vibration and provides an aggressive cutting structure, even after significant wear has occurred.