Matrix Drill Bit with Dual Surface Compositions and Methods of Manufacture

Abstract

Matrix drill bits and other downhole tools may be formed with one or more layers of hard materials disposed on exterior portions thereof. Exterior portions of used rotary drill bits or other downhole tools may be measured using three dimensional (3D) scanning techniques or other techniques to determine specific locations of undesired abrasion, erosion and/or wear. During the design of a new rotary drill bit or other downhole tool, computational flow analysis techniques may be used to determine potential locations for excessive erosions, abrasion, wear, impact and/or fatigue on exterior portions of the rotary drill bit or other downhole tools. One or more layers of hard material may be disposed at such locations on exterior portions of matrix bit bodies and other matrix bodies based on analyzing exterior portions of used downhole tools and/or computational flow analysis.

1 . A drill bit having a matrix bit body comprising:
 a plurality of cutting elements disposed at selected locations on exterior portions of the matrix bit body;   at least a first, matrix material having a first hardness satisfactory to form the matrix bit body;   the first, matrix material forming exterior portions of the matrix bit body associated with engaging and removing formation materials from a wellbore;   at least one layer of a second material disposed at one or more selected locations on exterior portions of the matrix bit body; and   the second material having a hardness greater than the first hardness of the first, matrix material to improve resistance of the matrix bit body at the selected location to erosion, abrasion, wear, impact and/or fatigue forces proximate the one or more selected locations.   
     
     
         2 . The drill bit of  claim 1  further comprising the second material selected from the group consisting of cemented carbides, composite carbides, spherical carbides, macrocrystalline tungsten carbides, cast carbides, low alloy sintered material and formulates thereof. 
     
     
         3 . The drill bit of  claim 1  wherein the at least one layer of second material further comprises:
 a composite layer formed from two or more sublayers of the second material;   each sublayer including an adhesive material with pellets of the second material disposed therein;   particles of the first matrix material disposed within each adhesive layer; and   the pellets of the second material substantially larger than the particles of the first matrix material.   
     
     
         4 . The drill bit of  claim 1  wherein the second material further comprises tungsten carbide pellets. 
     
     
         5 . The drill bit of  claim 1  wherein the second material further comprises crushed sintered tungsten carbide. 
     
     
         6 . The drill bit of  claim 1  wherein the second material further comprises at least fifty percent (50%) tungsten carbide pellets by weight. 
     
     
         7 . The drill bit of  claim 1  wherein the second material further comprises at least seventy percent (70%) tungsten carbide pellets by weight. 
     
     
         8 . The drill bit of  claim 1  wherein the second material further comprises tungsten carbide pellets formed with binding material in a range of approximately three percent (3%) or greater and less than five percent (5%) of the weight of such tungsten carbide pellets. 
     
     
         9 . The drill bit of  claim 1  further comprising multiple layers of the second material disposed at each selected location on exterior portions of the matrix bit body. 
     
     
         10 . The drill bit of  claim 1  wherein the matrix bit body further comprises:
 multiple layers of the second material disposed at a plurality of selected locations of exterior portions of the matrix bit body improve resistance to abrasion, erosion, wear, impact and/or fatigue forces at the selected locations; and   small amounts of the first, matrix material disposed within the layers of the second material wherein the first, matrix material comprises less than twenty percent (20%) by weight of each layer of the second material.   
     
     
         11 . A matrix drill bit having a matrix bit body with composite exterior portions comprising:
 a plurality of blades disposed on and extending from exterior portions of the matrix bit body;   respective fluid paths disposed between adjacent blades whereby fluid associated with drilling a wellbore in a downhole formation may flow between adjacent blades through the respective fluid path;   a plurality of cutting elements disposed at selected locations on exterior portions of each blade;   the matrix bit body formed in part from at least a first, matrix material having a first hardness;   the first, matrix material forming exterior portions of the matrix bit body associated with engaging and removing formation materials from downhole locations in a wellbore;   respective layers of a second material disposed at selected locations on exterior portions of the matrix bit body which are generally associated with potential erosion, abrasion, wear, impact and/or fatigue forces of the matrix bit body; and   the second material having a second hardness greater than the first hardness of the first material whereby the layers of the second material cooperate with the first material to form a dual surface composition to improve resistance to erosion, abrasion, wear, impact and/or fatigue forces proximate the respective selected locations on the matrix bit body.   
     
     
         12 . The drill bit of  claim 11  further comprising the first material selected from the group consisting of cemented carbides, composite carbides, spherical carbides, macrocrystalline tungsten carbide powders, cast carbide powders and formulates thereof. 
     
     
         13 . The drill bit of  claim 11  further comprising the respective layers of the second material having a combined thickness between approximately 0.25 inches and 0.50 inches at one or more of the selected locations. 
     
     
         14 . The drill bit of  claim 11  further comprising a single layer of the second material having a combined thickness between approximately 0.25 inches and 0.50 inches at one or more of the selected locations. 
     
     
         15 . The drill bit of  claim 11  wherein the second material further comprises tungsten carbide pellets. 
     
     
         16 . The drill bit of  claim 11  wherein the second material further comprises tungsten carbide pellets formed with respective binding material in a range of approximately three percent (3%) or greater and less than five percent (5%) of the weight of such tungsten carbide pellets. 
     
     
         17 . The drill bit of  claim 16  wherein the second material further comprises the tungsten carbide pellets formed with a cobalt binder providing approximately four percent (4%) of the weight of such tungsten carbide pellets. 
     
     
         18 . The drill bit of  claim 11  wherein at least one layer the second material further comprises a mixture of encrusted diamond pellets and tungsten carbide pellets. 
     
     
         19 . The drill bits of  claim 11  wherein the matrix bit body further comprises:
 at least one nozzle opening extending through the matrix bit body to allow communication of drilling fluids from interior portions of the matrix bit body to exterior portions of the matrix bit body; and   a plurality of layers of the second material disposed proximate to the nozzle opening to minimize erosion of the matrix bit body from associated drilling fluids exiting from the nozzle opening.   
     
     
         20 . The drill bit of  claim 11  wherein the matrix bit body further comprises:
 each blade having a leading surface and a trailing surface; and   multiple layers of the second material disposed adjacent to the leading surface of each blade whereby the layers of the second material minimize erosion, abrasion and wear along the leading surface of each respective blade.   
     
     
         21 . The drill bit of  claim 11  wherein the matrix bit body further comprises:
 each blade having a plurality of pockets sized to receive a respective cutting element therein;   at least one layer of the second material disposed within each pocket; and   a respective cutting element securely disposed within each pocket whereby the respective layer of the second material minimize erosion, abrasion and/or wear of the pocket when the respective cutting element engages downhole formation materials to form a wellbore.   
     
     
         22 . The rotary drill bit of  claim 11  further comprising at least one layer of hard material disposed on exterior portions of the matrix bit body in at least one flow path disposed between associated blades. 
     
     
         23 . A method of making a matrix drill bit comprising:
 placing a respective layer of hard material at selected locations on interior portions of a matrix bit body mold;   placing a hollow bit blank in the matrix bit body mold;   placing at least one matrix material selected from the group consisting of cemented carbides, composite carbides, spherical carbides, macrocrystalline tungsten carbide and cast carbide and formulates thereof in the mold;   placing a binder material in the mold with the binder material disposed proximate the matrix material and the hollow bit blank;   heating the mold and the materials disposed therein to a selected temperature to allow the binder material to melt and infiltrate the matrix material and the layers of hard material and associated tungsten carbide pellets with hot, liquid binder material; and   cooling the mold and materials disposed therein to form a matrix bit body with multiple layers of hard disposed proximate selected locations on exterior portions of the matrix bit body.   
     
     
         24 . The method of  claim 23  further comprising forming interior portions of the matrix bit body with more than one matrix material. 
     
     
         25 . The method of  claim 23  further comprising forming multiple layers of tungsten carbide pellets at selected locations on exterior portions of the matrix bit body associated with engaging and removing downhole formation materials during formation of a wellbore. 
     
     
         26 . The method of  claim 23  further comprising forming multiple layers of crushed sintered tungsten carbide at selected locations on exterior portions of the matrix bit body associated with engaging and removing downhole formation materials during formation of a wellbore. 
     
     
         27 . The method of  claim 23  further comprising:
 determining potential locations for excessive erosion, abrasion and/or wear of exterior portions of the matrix bit body; and   placing the layers of hard material on interior portions of the matrix bit body mold corresponding with the potential locations for excessive erosion, abrasion and/or wear of exterior portions of the associated matrix bit body prior to placing the matrix material in the mold.   
     
     
         28 . The method of  claim 23  further comprising forming the layers of the hard material with respective dimensions including thickness selected to minimize erosion, abrasion and/or wear proximate the corresponding selected location on exterior portions of the matrix bit body. 
     
     
         29 . A method of making a matrix drill bit comprising:
 placing a respective first layer of adhesive material at selected locations on interior portions of a matrix bit body mold;   placing tungsten carbide pellets in each first layer of adhesive material;   placing a respective second layer of adhesive material on each first layer of adhesive material and associated tungsten carbide pellets;   placing additional tungsten carbide pellets in each second layer of adhesive material;   placing a hollow bit blank in the matrix bit body mold;   placing at least one matrix material selected from the group consisting of cemented carbides, composite carbides, spherical carbides, macrocrystalline tungsten carbide and cast carbide and formulates thereof in the mold;   placing a binder material in the mold with the binder material disposed proximate the matrix material and the hollow bit blank;   heating the mold and the materials disposed therein to a selected temperature to allow the binder material to melt and infiltrate the matrix material and the layers of adhesive material and associated tungsten carbide pellets with hot, liquid binder material; and   cooling the mold and materials disposed therein to form a matrix bit body with multiple layers of tungsten carbide pellets disposed proximate selected locations on exterior portions of the matrix bit body.   
     
     
         30 . The method of  claim 29  further comprising forming interior portions of the matrix bit body with more than one matrix material. 
     
     
         31 . The method of  claim 29  further comprising forming multiple layers of tungsten carbide pellets at selected locations on exterior portions of the matrix bit body associated with engaging and removing downhole formation materials during formation of a wellbore. 
     
     
         32 . The method of  claim 29  further comprising:
 determining potential locations for excessive erosion, abrasion and/or wear of exterior portions of the matrix bit body; and   placing a first layer of adhesive material with tungsten carbide pellets dispersed therein on interior of the portions of the matrix bit body mold corresponding with the potential locations for excessive erosion, abrasion and/or wear of exterior portions of the associated matrix bit body prior to placing the matrix material in the mold.   
     
     
         33 . The method of  claim 29  further comprising selecting the adhesive material from the group consisting of one component adhesives and two component adhesives. 
     
     
         34 . The method of  claim 29  further comprising forming the layers of second material with respective dimensions including thickness selected to minimize erosion, abrasion and/or wear proximate the corresponding selected location on exterior portions of the matrix bit body. 
     
     
         35 . The method of  claim 29  further comprising:
 forming the mold cavity with a plurality of displacements disposed therein and each displacement having a complex, arcuate configuration corresponding with a desired configuration for a respective fluid flow path disposed on exterior portions of the a head; and   forming the mold cavity with a plurality of negative blade profiles with each negative blade profile disposed between associated displacements and each negative blade profile having a complex, arcuate configuration corresponding with a desired configuration for a respective blade disposed on exterior portions of the bit head.   
     
     
         36 . The method of  claim 29  further comprising selecting an infiltration material from the group consisting of tungsten carbide, monotungsten carbide, ditungsten carbide, macro crystalline tungsten carbide, other metal carbides, metal borides, metal oxides, metal nitrides, polycrystalline diamond (PCD) or mixtures of such infiltration materials. 
     
     
         37 . A used drill bit having a matrix bit body comprising:
 a plurality of cutting elements disposed at selected locations on exterior portions of the matrix bit body;   at least a first, matrix material having a first hardness satisfactory to form the matrix bit body;   the first, matrix material forming exterior portions of the matrix bit body associated with engaging and removing formation materials from a wellbore;   at least one layer of a second material disposed at one or more selected locations on exterior portions of the matrix bit body after the used drill bit has been used to form at least one portion of a wellbore; and   the second material having a hardness greater than the first hardness of the first, matrix material to improve resistance of the matrix bit body at the selected location to erosion, abrasion, wear, impact and/or fatigue forces proximate the one or more selected locations.   
     
     
         38 . The used drill bit of  claim 37  further comprising the second material selected from the group consisting of cemented carbides, composite carbides, spherical carbides, macrocrystalline tungsten carbides, cast carbides, low alloy sintered material and formulates thereof. 
     
     
         39 . The used drill bit of  claim 37  wherein the at least one layer of second material further comprises:
 a composite layer formed from two or more sublayers of the second material;   each sublayer including an adhesive material with pellets of the second material disposed therein;   particles of the first matrix material disposed within each adhesive layer; and   the pellets of the second material substantially larger than the particles of the first matrix material.   
     
     
         40 . The used drill bit of  claim 37  wherein the second material further comprises tungsten carbide pellets. 
     
     
         41 . The used drill bit of  claim 37  wherein the second material further comprises crushed sintered tungsten carbide. 
     
     
         42 . The used drill bit of  claim 37  wherein the second material further comprises at least fifty percent (50%) tungsten carbide pellets by weight. 
     
     
         43 . The used drill bit of  claim 37  wherein the second material further comprises at least seventy percent (70%) tungsten carbide pellets by weight. 
     
     
         44 . The used drill bit of  claim 37  wherein the second material further comprises tungsten carbide pellets formed with binding material in a range of approximately three percent (3%) or greater and less than five percent (5%) of the weight of such tungsten carbide pellets. 
     
     
         45 . The used drill bits of  claim 37  wherein the matrix bit body further comprises:
 multiple layers of the second material disposed at a plurality of selected locations of exterior portions of the matrix bit body improve resistance to abrasion, erosion, wear, impact and/or fatigue forces at the selected locations; and   small amounts of the first, matrix material disposed within the layers of the second material wherein the first, matrix material comprises less than twenty percent (20%) by weight of each layer of the second material.   
     
     
         46 . A matrix drill bit having a matrix bit body with composite exterior portions comprising:
 a plurality of blades disposed on and extending from exterior portions of the matrix bit body;   respective fluid paths disposed between adjacent blades whereby fluid associated with drilling a wellbore in a downhole formation may flow between adjacent blades through the respective fluid path;   a plurality of cutting elements disposed at selected locations on exterior portions of each blade;   the matrix bit body formed in part from at least a first, matrix material having a first hardness;   the first, matrix material forming exterior portions of the matrix bit body associated with engaging and removing formation materials from downhole locations in a wellbore;   at least one recess formed in exterior portions of the matrix bit body at a selected location generally associated with potential erosion, abrasion, wear, impact and/or fatigue forces on the matrix bit body;   at least one layer of a second material disposed in each recess at the respective selected location on exterior portions of the matrix bit body; and   the second material having a second hardness greater than the first hardness of the first material whereby the layers of the second material cooperate with the first material to form a dual surface composition to improve resistance to erosion, abrasion, wear, impact and/or fatigue forces proximate the respective selected location of the recess on the matrix bit body.   
     
     
         47 . The drill bit of  claim 46  further comprising the first material selected from the group consisting of cemented carbides, composite carbides, spherical carbides, macrocrystalline tungsten carbide powders, cast carbide powders and formulates thereof. 
     
     
         48 . The drill bit of  claim 46  wherein the second material further comprises tungsten carbide pellets. 
     
     
         49 . The drill bit of  claim 46  wherein the second material further comprises tungsten carbide pellets formed with respective binding material in a range of approximately three percent (3%) or greater and less than five percent (5%) of the weight of such tungsten carbide pellets. 
     
     
         50 . The drill bit of  claim 46  wherein the second material further comprises the tungsten carbide pellets formed with a cobalt binder providing approximately four percent (4%) of the weight of such tungsten carbide pellets. 
     
     
         51 . The drill bit of  claim 46  wherein at least one layer the second material further comprises a mixture of encrusted diamond pellets and tungsten carbide pellets. 
     
     
         52 . The drill bits of  claim 46  wherein the matrix bit body further comprises:
 at least one nozzle opening extending through the matrix bit body to allow communication of drilling fluids from interior portions of the matrix bit body to exterior portions of the matrix bit body;   the recess disposed proximate the at least one nozzle opening; and   a plurality of layers of the second material disposed in the recess proximate to the nozzle opening to minimize erosion of the matrix bit body from associated drilling fluids exiting from the nozzle opening.   
     
     
         53 . The drill bit of  claim 46  wherein the matrix bit body further comprises:
 each blade having a leading surface and a trailing surface;   all respective recesses formed in the leading surface of each blade; and   multiple layers of the second material disposed in each respective recess adjacent to the leading surface of each blade whereby the layers of the second material minimize erosion, abrasion and wear along the respective leading surface of each respective blade.   
     
     
         54 . The drill bit of  claim 46  wherein the matrix bit body further comprises:
 each blade having a plurality of pockets sized to receive a respective cutting element therein;   at least one recess formed on exterior portions of each blade proximate at least one pocket; and   at least one layer of a second hard material disposed in each recess;   whereby the respective layers of the second material minimize erosion, abrasion and/or wear of the associated pockets when the respective cutting element engages downhole formation materials to form a wellbore.   
     
     
         55 . The rotary drill bit of  claim 46  further comprising at least one layer of hard material disposed in a recess at a selected location in at least one flow path disposed between associated blades.