DRILL BIT AND CUTTING INSERTS FOR HARD/ABRASIVE FORMATIONS

摘要

A rolling cone drill bit comprises a plurality of bottomhole cutter elementspositioned in a firstcircumferential row, wherein at least one of the cutter elements comprises acutting portion extendingfrom a base portion to a point furthermost from the base portion, defining anextension height. The ratioof the cross-sectional area of the cutter element at a point equal to ninety-four percent of the extensionheight to the cross-sectional area of the cutter element base is greater than0.2. Moreover, the ratio of theextension height to the base diameter is not greater than 0.75.