Methods of making earth-boring tools and methods of drilling with earth-boring tools

Abstract

Method of making an earth-boring tool comprise forming a body comprising a face including a plurality of radially extending blades thereon and a cone region, a nose region, and a shoulder region. A plurality of cutting elements may be disposed on the blades at least in the cone region, the nose region, and the shoulder region. Some of the cutting elements may be configured to form kerfing pairs comprising at least two cutting elements disposed on different blades of the plurality of radially extending blades at least substantially at the same radial position from a central axis of the body. At least one of the blades and orientations and exposures of the plurality of cutting elements may be configured so that a summation of a lateral drilling force generated by each cutting element of the plurality of cutting elements is directed toward a lateral side of the body.

1 . A method of making an earth-boring tool, comprising:
 forming a body comprising a face at a leading end thereof, the face including a plurality of radially extending blades thereon and a cone region, a nose region, and a shoulder region;   disposing a plurality of cutting elements on blades of the plurality of radially extending blades, at least one cutting element of the plurality of cutting elements being disposed at least substantially at the same radial position relative to an axis of rotation of the body as at least another cutting element of the plurality of cutting elements on a different blade of the plurality of radially extending blades to follow at least substantially the same cutting path when the tool is rotated about its axis;   placing a first group of cutting elements of the plurality of cutting elements located in the cone region at a greater relative exposure than a relative exposure of a second group of cutting elements of the plurality of cutting elements located in the shoulder region; and   configuring at least one of the plurality of radially extending blades and orientations and exposures of the plurality of cutting elements so that a summation of a lateral drilling force generated by each cutting element of the plurality of cutting elements is directed toward a lateral side of the body.   
     
     
         2 . The method of  claim 1 , further comprising:
 selecting the first group of cutting elements to exhibit a first cutting face size; and   selecting the second group of cutting elements to comprise a second, smaller cutting face size.   
     
     
         3 . The method of  claim 2 , further comprising selecting the plurality of cutting elements further to include a third group of cutting elements positioned radially outward from the second group relative to the axis of rotation of the body, the cutting elements comprising the third group having a smaller cutting face than the cutting elements comprising the second group. 
     
     
         4 . The method of  claim 1 , wherein disposing the plurality of cutting elements on the blades of the plurality of radially extending blades comprises disposing cutting elements in a cone region at a greater aggressiveness than cutting elements disposed in a shoulder region. 
     
     
         5 . A method of forming a borehole, comprising:
 drilling a subterranean formation with a rotary drill bit operating at a relatively low weight-on-bit (WOB), the rotary drill bit comprising a plurality of cutting elements disposed over a face thereof;   stabilizing the rotary drill bit drilling at the low WOB with kerfs formed by cutting elements of the plurality of cutting elements;   increasing the WOB applied to the rotary drill bit to drill the subterranean formation with the rotary drill bit operating at a relatively high WOB; and   stabilizing the rotary drill bit drilling at the high WOB with a directed lateral force exerted by the rotary drill bit against a sidewall of the borehole, the directed lateral force comprising a summation of a lateral force generated during drilling by each cutting element of the plurality of cutting elements.   
     
     
         6 . The method of  claim 5 , wherein drilling the subterranean formation with the rotary drill bit operating at the relatively low WOB comprises drilling the subterranean formation with the rotary drill be operating at a WOB less than about 20,000 lb, and wherein drilling the subterranean formation with the rotary drill bit operating at the relatively high WOB comprises drilling the subterranean formation with the rotary drill be operating at a WOB of about 20,000 lb or greater. 
     
     
         7 . The method of  claim 5 , wherein stabilizing the rotary drill bit drilling at the low WOB with kerfs comprises cutting material from the subterranean formation with at least two cutting elements located at least substantially at the same radial position with respect to a central axis of the rotary drill bit on different blades of a plurality of blades of the rotary drill bit, wherein a leading cutting element forms a kerf in the subterranean formation and at least one following cutting element each of the two or more cutting elements follows substantially a same kerf to increase the kerf depth and inhibit lateral displacement of the rotary drill bit. 
     
     
         8 . The method of  claim 2 , wherein selecting the first group of cutting elements to exhibit the first cutting face size and selecting the second group of cutting elements to comprise the second, smaller cutting face size comprises selecting the first and second groups of cutting elements to have cutting face sizes of between 4 mm and 30 mm in diameter. 
     
     
         9 . The method of  claim 8 , wherein selecting the first group of cutting elements to exhibit the first cutting face size comprises selecting cutting elements of the first group of cutting elements to have cutting faces of about 13 mm in diameter and wherein selecting the second group of cutting elements to comprise the second, smaller cutting face size comprises selecting cutting elements of the second group of cutting elements to have cutting faces of about 11 mm in diameter. 
     
     
         10 . The method of  claim 1 , further comprising disposing the at least one cutting element on a side of the face at least substantially opposing another side of the face on which the at least another cutting element is disposed. 
     
     
         11 . The method of  claim 1 , further comprising disposing the at least one cutting element at a first relative exposure and disposing the at least another cutting element at a second, different relative exposure. 
     
     
         12 . The method of  claim 1 , further comprising selecting the at least one cutting element to comprise at least one of a first shape, a first chamfer, a first rake angle, a first diamond grade, a first abrasion resistance, and a first impact resistance and selecting the at least another cutting element to comprise at least one of a second, different shape, a second, different chamfer, a second, different rake angle, a second, different diamond grade, a second, different abrasion resistance, and a second, different impact resistance. 
     
     
         13 . The method of  claim 1 , wherein disposing the plurality of cutting elements on blades of the plurality of radially extending blades comprises disposing the at least one cutting element at a radial position within 0.200 in of a radial position of the at least another cutting element relative to the axis of rotation of the body. 
     
     
         14 . The method of  claim 5 , wherein stabilizing the rotary drill bit drilling at the high WOB with the directed lateral force exerted by the rotary drill bit against the sidewall of the borehole comprises stabilizing the rotary drill bit with a directed lateral force of between 8% and 25% of the high WOB. 
     
     
         15 . The method of  claim 5 , wherein stabilizing the rotary drill bit drilling at the low WOB with kerfs formed by cutting elements of the plurality of cutting elements comprises restraining lateral movement of at least one cutting element of the plurality of cutting elements on a first blade of a plurality of blades of the rotary drill bit against a sidewall of a kerf formed by at least another cutting element of the plurality of cutting elements on a second, different blade of the plurality of blades. 
     
     
         16 . The method of  claim 15 , wherein restraining lateral movement of the at least one cutting element on the first blade against the sidewall of the kerf formed by the at least another cutting element on the second, different blade comprises rotating the at least one cutting element in a first cutting path within about 0.200 in of a second cutting path in which the at least another cutting element is rotated. 
     
     
         17 . The method of  claim 15 , wherein restraining lateral movement of the at least one cutting element on the first blade against the sidewall of the kerf formed by the at least another cutting element on the second, different blade comprises rotating the at least one cutting element at a first relative exposure and rotating the at least another cutting element at a second, different relative exposure. 
     
     
         18 . The method of  claim 5 , further comprising engaging the subterranean formation with a first group of cutting elements of the plurality of cutting elements in a cone region of the face at a greater relative exposure than a relative exposure of a second group of cutting elements of the plurality of cutting elements in a shoulder region of the face. 
     
     
         19 . The method of  claim 18 , wherein engaging the subterranean formation with the first group of cutting elements in the cone region at the greater relative exposure than the relative exposure of the second group of cutting elements in the shoulder region comprises engaging the subterranean formation with the first group of cutting elements exhibiting a first cutting face size greater than a second cutting face size of the second group of cutting elements. 
     
     
         20 . The method of  claim 19 , wherein engaging the subterranean formation with the first group of cutting elements exhibiting a first cutting face size greater than a second cutting face size of the second group of cutting elements comprises engaging the subterranean formation with the first group of cutting elements exhibiting a first cutting face size of about 13 mm in diameter and the second group of cutting elements exhibiting a second cutting face size of about 11 mm in diameter.