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

Abstract

A cutter element is provided for use on a rotary drill bit of a drilling string to cut earthen formation and the like. The cutter element includes a cutting portion formed from cutting material adapted to cut into the earthen formation, and a substrate positioned adjacent the cutting portion. The cutting portion and the substrate form a 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 form the front face and spaced outwardly from the longitudinal axis. The cutting portion includes a cutting face that provides at least a portion of the front face. The cutting portion extends longitudinally inward from the front face to a back surface engaging or inter-facing the substrate. Thus, a distinct, longitudinally extending volume of cutting material is provided and includes a predesignated 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.

1 . A cutter element for use on a rotary drill bit attach to a drill string to cut earthen formations and the like, said cutter element comprising:
 a cutting portion formed from cutting material adapted to cut the earthen formation; and   a substrate positioned adjacent the cutting portion;
 wherein the cutting portion and the substrate form a 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 outwardly 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 engaging the substrate, such that a distinct, longitudinally extending volume of cutting material is provided and includes a predesignated portion of the circumferential surface that extends from the cutting face to the back surface, the predesignated circumferential surface portion being predesignated for wearing contact with the earthen formation. 
   
     
     
         2 . The cutter element of  claim 1 , wherein the back surface deviates from normal angular relation with the longitudinal axis, such that the longitudinal distance between the front face and locations on the back surface varies. 
     
     
         3 . The cutter element of  claim 2 , wherein the front face consists entirely of the cutting face of the cutting portion. 
     
     
         4 . The cutter element of  claim 2 , wherein the cutting portion is configured such that at least one longitudinal cross-section of the cutter element, generally normal to the front face, reveals a cross-sectional area of the cutting portion with a larger area on one side of the longitudinal axis than on an opposite side of the longitudinal axis. 
     
     
         5 . The cutter element of  claim 2 , wherein the cutting portion is configured such that at least one longitudinal cross-sectional view of the cutter element, generally normal to the front face, reveals an exposed circumferential surface of the cutting portion in one half of the cross-section that is longer than a corresponding exposed circumferential surface portion of the cutting portion on an opposite half of the cross-section. 
     
     
         6 . The cutter element of  claim 2 , 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. 
     
     
         7 . The cutter element of  claim 2 , wherein at least one longitudinal cross-sectional view of the cutting element, generally normal to the front face, reveals a longitudinally extending area of the distinct longitudinal volume of cutting material, the area having a thickness that is reduced as the area extends in the longitudinally inward direction. 
     
     
         8 . The cutter element of  claim 1 , wherein the volume of cutting material located in the vicinity of the predesignated circumferential surface portion substantially larger than the volume of cutting material located in the vicinity of other portions of the circumferential surface. 
     
     
         9 . The cutter element of  claim 1 , wherein the substrate form a portion of the front face. 
     
     
         10 . The cutter element of  claim 1 , wherein a lateral cross-sectional view through the cutting portion, generally normal to the longitudinal axis, reveals the substrate forming a portion of the exposed circumference of the cutter element. 
     
     
         11 . The cutter element of  claim 10 , wherein the cutting portion is configured such that any lateral cross-sectional view through the cutting portion, generally normal to the longitudinal axis, reveals the substrate forming a portion of the exposed circumference of the cutting element. 
     
     
         12 . The cutter element of  claim 1 , further comprising a bore extending from a portion of the circumferential surface to a portion of the cutting face, the cutting portion being situated therein. 
     
     
         13 . The cutter element of  claim 1 , wherein the cutter portion includes a reinforcing cutter material providing the distinct longitudinally extending volume. 
     
     
         14 . The cutter element of  claim 1 , wherein the cutting material is polycrystalline diamond. 
     
     
         15 . The cutter element of  claim 1 , wherein the cutting portion and the substrate form a substantially rod shaped body having a circumferential surface spaced radially from and in generally parallel relation with the longitudinal axis. 
     
     
         16 . 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. 
   
     
     
         17 . The cutter element of  claim 16 , wherein the cutting portion is configured such that at least one longitudinal cross-section of the cutter element, generally normal to the front face, reveals a cross-sectional area of the cutting portion with a larger area on one side of the longitudinal axis than on an opposite side of the longitudinal axis. 
     
     
         18 . The cutter element of  claim 17 , wherein the back surface deviates from normal angular relation with the longitudinal axis, such that the longitudinal distance between the front face and locations on the back surface varies. 
     
     
         19 . The cutter element of  claim 18 , wherein the cutting portion is configured such that at least one longitudinal cross-sectional view of the cutter element, generally normal to the front face, reveals an exposed circumferential surface of the cutting portion on one side of the longitudinal axis that is longer than a corresponding exposed circumferential surface portion of the cutting portion on an opposite side of the longitudinal axis. 
     
     
         20 . The cutter element of  claim 16 , wherein the front face consists entirely of the cutting face of the cutting portion. 
     
     
         21 . The cutter element of  claim 16 , wherein at least one longitudinal cross-sectional view of the cutting element, generally normal to the front face, reveals a longitudinally extending area of the distinct longitudinal volume of cutting material, the area having a thickness that is reduced as the area extends in the longitudinally inward direction. 
     
     
         22 . The cutter element of  claim 16 , wherein the volume of cutting material located in the vicinity of the predesignated circumferential surface portion is substantially larger than the volume of cutting material located in the vicinity of other portions of the circumferential surface. 
     
     
         23 . The cutter element of  claim 16 , wherein the substrate provides a portion of the front face. 
     
     
         24 . The cutter element of  claim 16 , wherein the cutting portion is configured such that any lateral cross-sectional view through the cutting portion, generally normal to the longitudinal axis, reveals the substrate forming a portion of the exposed circumference of the cutter element. 
     
     
         25 . 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.