Abstract: An earth-boring drill bit is described, the bit having a bit body having a central longitudinal axis that defines an axial center of the bit body and configured at its upper extent for connection into a drill string; at least one primary fixed blade extending downwardly from the bit body and inwardly toward, but not proximate to, the central axis of the drill bit; at least one secondary fixed blade extending radially outward from proximate the central axis of the drill bit; a plurality of fixed cutting elements secured to the primary and secondary fixed blades; at least one bit leg secured to the bit body; and a rolling cutter mounted for rotation on the bit leg; wherein the fixed cutting elements on at least one fixed blade extend from a center of the bit outward toward a gage region of the bit but do not include a gage cutting region, and wherein at least one roller-cone cutter portion extends from substantially the drill bit's gage region inwardly toward the center of the bit, an apex of the roller-cone cu

Abstract: An earth-boring drill bit is described, the bit having a bit body having a central longitudinal axis that defines an axial center of the bit body and configured at its upper extent for connection into a drill string; at least one primary fixed blade extending downwardly from the bit body and inwardly toward, but not proximate to, the central axis of the drill bit; at least one secondary fixed blade extending radially outward from proximate the central axis of the drill bit; a plurality of fixed cutting elements secured to the primary and secondary fixed blades; at least one bit leg secured to the bit body; and a rolling cutter mounted for rotation on the bit leg; wherein the fixed cutting elements on at least one fixed blade extend from a center of the bit outward toward a gage region of the bit but do not include a gage cutting region, and wherein at least one roller cone cutter portion extends from substantially the drill bit's gage region inwardly toward the center of the bit, an apex of the roller cone cu

Abstract: An earth boring drill bit is described, the bit having a bit body having a central longitudinal axis that defines an axial center of the bit body and configured at its upper extent for connection into a drillstring; at least one primary fixed blade extending downwardly from the bit body and inwardly toward, but not proximate to, the central axis of the drill bit; at least one secondary fixed blade extending radially outward from proximate the central axis of the drill bit; a plurality of fixed cutting elements secured to the primary and secondary fixed blades; at least one bit leg secured to the bit body; and a rolling cutter mounted for rotation on the bit leg; wherein the fixed cutting elements on at least one fixed blade extend from the center of the bit outward toward the gage of the bit but do not include a gage cutting region, and wherein at least one roller cone cutter portion extends from substantially the drill bit's gage region inwardly toward the center of the bit, the apex of the roller cone cutte

Abstract: An earth-boring drill bit is described, the bit having a bit body having a central longitudinal axis that defines an axial center of the bit body and configured at its upper extent for connection into a drill string; at least one primary fixed blade extending downwardly from the bit body and inwardly toward, but not proximate to, the central axis of the drill bit; at least one secondary fixed blade extending radially outward from proximate the central axis of the drill bit; a plurality of fixed cutting elements secured to the primary and secondary fixed blades; at least one bit leg secured to the bit body; and a rolling cutter mounted for rotation on the bit leg; wherein the fixed cutting elements on at least one fixed blade extend from the center of the bit outward toward the gage of the bit but do not include a gage cutting region, and wherein at least one roller cone cutter portion extends from substantially the drill bit's gage region inwardly toward the center of the bit, the apex of the roller cone cutt

Abstract: An earth boring drill bit is described, the bit having a bit body having a central longitudinal axis that defines an axial center of the bit body and configured at its upper extent for connection into a drillstring; at least one primary fixed blade extending downwardly from the bit body and inwardly toward, but not proximate to, the central axis of the drill bit; at least one secondary fixed blade extending radially outward from proximate the central axis of the drill bit; a plurality of fixed cutting elements secured to the primary and secondary fixed blades; at least one bit leg secured to the bit body; and a rolling cutter mounted for rotation on the bit leg; wherein the fixed cutting elements on at least one fixed blade extend from the center of the bit outward toward the gage of the bit but do not include a gage cutting region, and wherein at least one roller cone cutter portion extends from substantially the drill bit's gage region inwardly toward the center of the bit, the apex of the roller cone cutte

Abstract: An earth-boring bit has a high density row on one of its cones. Each cone has a nose area and a gage area with a heel row of teeth at the gage area. One of the cones has a farther intermediate row of teeth and another one of the cones has a closer intermediate row of teeth. The remaining cone has a high density row of teeth, which is located closer to the axis of rotation of the bit than the farther intermediate row and farther from the axis of rotation of the bit than the closer intermediate row. The high density row has a smaller pitch between crests of the teeth than the closer and farther intermediate rows. The smaller pitch provides more teeth in the high density row than in the closer intermediate row and the farther intermediate row.