SINGLE-CONE ROCK BIT HAVING CUTTING STRUCTURE ADAPTED TO IMPROVE HOLE CLEANING, AND TO REDUCE TRACKING AND BIT BALLING

摘要

A roller cone drill bit is disclosed which includes a bit body adapted to be coupled to a drill string, a bearing journal depending from the bit body and a singl e roller cone rotatably attached to the journal. The roller cone has a plurality of insert s disposed thereon. In one aspect, the inserts have an extension length of at least 0.6 inches. A roller cone drill bit is disclosed, including a bit body, a bearing journal depending from the bit body, and a single roller cone rotatably attached to the journal. Th e roller cone has a plurality of inserts disposed thereon. In another aspect, the inserts are arranged such that at most about 20 percent of the inserts are crossed substantially at centerlines thereof by any single plane which contains the axis of the cone axis 10 and which crosses at least two of the inserts.