Method, System, and Apparatus of Cutting Earthen Formations and the like

A cutter element for use on a rotary drill bit of a drill string to cut earthen formations and the like, said cutter element comprising:

• a cutting portion formed substantially from polycrystalline diamond material adapted to cut the earthen formation;
• and
• a substrate positioned adjacent the cutting portion;
• wherein the cutting portion and the substrate form a substantially rod shaped body having a substantially planar front face, a longitudinal axis extending centrally through the front face and the substrate, and a circumferential surface extending inwardly from the front face and spaced radially from the longitudinal axis;
• and
• wherein the cutting portion includes a cutting face providing at least a portion of the front face, the cutting portion extending longitudinally inward from the front face to a back surface interfacing the substrate, such that a distinct, longitudinally extending volume of cutting material is provided and includes a portion of the circumferential surface that extends from the cutting face to the back surface, the circumferential surface portion being predesignated for wearing contact with the earthen formation;
• and
• wherein the cutting portion is configured such that a lateral cross-sectional view of the cutting element, generally normal to the longitudinal axis, reveals a larger area of the cutting portion concentrated in one half of the cross-section adjacent the predesignated circumferential surface portion than in an opposite half of the cross-section.

A method of drilling a borehole, comprising the steps of:

• providing a drill bit having a plurality of cutting elements thereon, the cutting elements having,
• a cutting portion formed substantially from polycrystalline diamond material adapted to cut the earthen formation;
• and
• a substrate positioned adjacent the cutting portion;
• wherein the cutting portion and the substrate form a substantially rod shaped body having a substantially planar front face, a longitudinal axis extending centrally through the front face and the substrate, and a circumferential surface extending inwardly from the front face and spaced radially from the longitudinal axis;
• wherein the cutting portion includes a cutting face providing at least a portion of the front face, the cutting portion extending longitudinally inward from the front face to a back surface interfacing the substrate, such that a distinct, longitudinally extending volume of cutting material is provided and includes a portion of the circumferential surface that extends from the cutting face to the back surface, the circumferential surface portion being predesignated for wearing contact with the earthen formation;
• and
• wherein the cutting portion is configured such that a lateral cross-sectional view of the cutting element, generally normal to the longitudinal axis, reveals a larger area of the cutting portion concentrated in one half of the cross-section adjacent the predesignated circumferential surface portion than in an opposite half of the cross-section;
• mounting the bit on the end of a drill string;
• directing the drill bit at a position such that the cutting elements engage the earthen formation at an angle, whereby the predesignated circumferential surface portion is in contact with the earthen formation;
• and
• operating the drill string such that the drill bit and the cutting elements cut into the earthen formation, thereby creating a wear flat along the predesignated circumferential surface portion.