Drill bits and earth-boring tools including shaped cutting elements

摘要

Cutting elements for an earth-boring tool include a substrate base and a cutting tip. The cutting tip may include a first generally conical surface, a second, opposite generally conical surface, a first flank surface extending between the first and second generally conical surfaces, and a second, opposite flank surface. The cutting tip may include a central axis that is not co-linear with a longitudinal axis of the substrate base. The cutting tip may include a surface defining a longitudinal end thereof that is relatively more narrow in a central region thereof than in a radially outer region thereof. Earth-boring tools include a body and a plurality of such cutting elements attached thereto, at least one cutting element oriented to initially engage a formation with the first or second generally conical surface thereof. Methods of drilling a formation use such cutting elements and earth-boring tools.

主权项

1. A fixed-cutter earth-boring rotary drill bit, comprising:
a bit body bearing fixed blades; and cutting elements secured to the fixed blades of the bit body, at least some of the cutting elements comprising: a substrate base comprising a substantially cylindrical outer side surface and a longitudinal axis substantially parallel to the substantially cylindrical outer side surface; and a cutting tip comprising:
an elongated surface defining a longitudinal end of the cutting tip;a first generally conical surface extending from proximate the substrate base to the elongated surface;a second generally conical surface extending from proximate the substrate base to the elongated surface, the second generally conical surface opposite the first generally conical surface;a first generally flat surface extending between the first generally conical surface, the second generally conical surface, and the elongated surface;a second generally flat surface extending between the first generally conical surface, the second generally conical surface, and the elongated surface, the second generally flat surface opposite the first generally flat surface; anda central axis extending through the cutting tip from an interface between the substrate base and the cutting tip to a central location on the elongated surface; wherein a width of the longitudinal end of the cutting tip varies along a length of the elongated surface; and wherein at least some of the cutting elements are positioned such that at least one of the first generally conical surface or the second generally conical surface initially engages a formation to be bored with the fixed-cutter earth-boring rotary drill bit by being oriented in a back raked position and each of the first generally flat surface and the second generally flat surface of the cutting tip is configured to stabilize the respective cutting element within at least one groove cut in the formation.