Patent ID: 7690442
Filing Date: 2010-04-06
Classification: E21B

Abstract:
1. A rolling cone drill bit for drilling a borehole in earthen formations, the bit comprising: a bit body having a bit axis; at least one rolling cone cutter mounted on the bit body for rotation about a cone axis and having a first surface for cutting the borehole bottom and a second surface for cutting the borehole sidewall; a plurality of cutter elements secured to the cone cutter and extending from the first surface and positioned in a first circumferential row; at least one of the cutter elements comprising a cutter element axis, a base portion having a diameter, and a cutting portion extending from the base portion to a point furthermost from the base portion defining an extension height; wherein the ratio of the cross-sectional area of the cutter element defined by a plane perpendicular to the cutter element axis at a point equal to ninety-four percent of the extension height to the cross-sectional area of the cutter element base defined by a plane perpendicular to the cutter element axis is greater than 0.2; and wherein the ratio of the extension height to the base diameter is not greater than 0.75.