Improved anti-whirl drill bit.

摘要

An anti-whirl rotary drag bit (10) including one or more cutters (34-38), wear knots or other support structures disposed on the flank (40) of a bit profile in a normally cutter-devoid region of the profile adjacent the gage of the bit in the circumferential segment of the gage (14) used as a bearing zone (12) for the bit to ride against the side of the bore hole. Such flank cutters (34-38) or other structures reduce wear of the bearing zone (12) but, due to their placement, do not come into play except under certain drilling situations such as reaming or high rates of penetration wherein whirl tendencies resulting from cutting forces are not as pronounced. <IMAGE>