Earth-boring tools and methods of forming earth-boring tools

Abstract

An earth-boring tool comprises a body, a plurality of blades, and cutting elements. The body has a face at a leading end thereof and comprises a cone region, a nose region, a flank region, a shoulder region, and a gage region. The plurality of blades extends longitudinally and radially over the face. The cutting elements are disposed within the shoulder region of the body on different blades of the plurality of blades than one another, a first of the cutting elements exhibiting a different size than a second of the cutting elements. A method of forming an earth-boring tool and a method of forming a borehole in a subterranean formation are also described.

1 . An earth-boring tool, comprising:
 a body having a face at a leading end thereof and comprising a cone region, a nose region, a flank region, a shoulder region, and a gage region;   a plurality of blades extending longitudinally and radially over the face; and   cutting elements disposed within the shoulder region of the body on different blades of the plurality of blades than one another, a first of the cutting elements provided in a rotationally leading position relative to a second of the cutting elements and exhibiting a smaller size than the second of the cutting elements.   
     
     
         2 . (canceled) 
     
     
         3 . The earth-boring tool of  claim 1 , wherein a third of the cutting elements is provided in a rotationally trailing position relative to the second of the cutting elements and exhibits a larger size than the second of the cutting elements. 
     
     
         4 . A method of forming an earth-boring tool, comprising:
 forming a body having a face at a leading end thereof and comprising a cone region, a nose region, a flank region, a shoulder region, and a gage region;   disposing a first cutting element within the shoulder region of the body on a first blade extending longitudinally and radially over the face; and   disposing a second cutting element within the shoulder region of the body on a second blade extending longitudinally and radially over the face and rotationally trailing the first blade, the second cutting element exhibiting a larger diameter than the first cutting element.   
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 4 , further comprising disposing the second cutting element directly radially adjacent the first cutting element. 
     
     
         7 . The method of  claim 4 , further comprising disposing additional cutting elements within one or more of the cone region, the nose region, the flank region, and the gage region of the body, one or more of the first cutting element and the second cutting element exhibiting a larger size than any of the additional cutting elements. 
     
     
         8 . The method of  claim 7 , further comprising selecting the first cutting element and the second cutting element to each individually exhibit a larger cutting face than any of the additional cutting elements. 
     
     
         9 . The method of  claim 7 , further comprising selecting each of the additional cutting elements to exhibit substantially the same size as one another. 
     
     
         10 . The method of  claim 4 , further comprising disposing a third cutting element within the shoulder region of the body on a third blade extending longitudinally and radially over the face and rotationally trailing the second blade, the third cutting element exhibiting a larger diameter than each of the first cutting element and the second cutting element. 
     
     
         11 . The method of  claim 10 , further comprising disposing the third cutting element directly radially adjacent the second cutting element. 
     
     
         12 . The method of  claim 4 , wherein disposing a second cutting element within the shoulder region of the body on a second blade comprises positioning the second cutting element to be underexposed relative to the first cutting element. 
     
     
         13 . The method of  claim 4 , wherein disposing a second cutting element within the shoulder region of the body on a second blade comprises disposing the second cutting element at a different radial position within the shoulder region of the body than the first cutting element. 
     
     
         14 . An earth-boring tool, comprising:
 a body having a face at a leading end thereof and comprising a cone region, a nose region, a flank region, a shoulder region, and a gage region;   a first cutting element located within the shoulder region of the body on a first blade extending longitudinally and radially over the face of the body; and   a second cutting element located within the shoulder region of the body on a second blade extending longitudinally and radially over the face of the body and rotationally trailing the first blade, the second cutting element exhibiting a larger diameter than the first cutting element.   
     
     
         15 . The earth-boring tool of  claim 14 , further comprising additional cutting elements located within one or more of the cone region, the nose region, the flank region, and the gage region of the body on one or more of the first blade and the second blade, the additional cutting elements exhibiting a smaller diameter than one or more of the first cutting element and the second cutting element. 
     
     
         16 . The earth-boring tool of  claim 14 , wherein the first blade is positioned circumferentially adjacent the second blade. 
     
     
         17 . The earth-boring tool of  claim 14 , wherein a ratio between a diameter of the first cutting element and a diameter of the second cutting element is within a range of from about 0.32:1 to about 0.84:1. 
     
     
         18 . The earth-boring tool of  claim 14 , further comprising a third cutting element located within the shoulder region of the body on third blade extending longitudinally and radially over the face of the body and rotationally trailing the second blade, the third cutting element exhibiting a larger diameter than the second cutting element. 
     
     
         19 . The earth-boring tool of  claim 18 , wherein:
 the second cutting element is underexposed relative to the first cutting element; and   the third cutting element is underexposed relative to the second cutting element.   
     
     
         20 . The earth-boring tool of  claim 14 , wherein the first cutting element and the second cutting element are radially positioned relative to one another such that rotational paths for the first cutting element and the second cutting element overlap one another proximate outermost lateral boundaries of the rotational paths. 
     
     
         21 . The earth-boring tool of  claim 14 , wherein the first cutting element and the second cutting element are radially positioned relative to one another such that rotational paths for the first cutting element and the second cutting element overlap one another proximate lowermost longitudinal boundaries of the rotational paths. 
     
     
         22 . The earth-boring tool of  claim 14 , wherein the first cutting element and the second cutting element are radially positioned relative to one another such that rotational paths for the first cutting element and the second cutting element overlap one another a location intermediate between outermost lateral boundaries and lowermost longitudinal boundaries of the rotational paths.