Bit with co-radial cutting profile and cutting element

Abstract

A cutting tool may include multiple blades extending from a bit body, and multiple cutting elements coupled to the blades. First cutting elements and a second cutting element coupled to the blades may collectively define a cutting profile of the bit. The second cutting element may be substantially larger than at least some of the first cutting elements and may substantially define a nose region of the cutting profile.

What is claimed is: 
     
         1 . A cutting tool, comprising:
 a bit body;   a plurality of blades extending from the bit body;   a plurality of first cutting elements each coupled to a corresponding one of the plurality of blades; and   a second cutting element coupled to one of the plurality of blades and defining with the plurality of first cutting elements a cutting profile, the second cutting element substantially defining a nose region of the cutting profile and being substantially larger than at least one of the plurality of first cutting elements.   
     
     
         2 . The cutting tool of  claim 1 , the plurality of first cutting elements and the second cutting element each including a substrate and a diamond layer, and at least one of the plurality of first cutting elements or the second cutting element exhibiting at least one of a back rake or a side rake. 
     
     
         3 . The cutting tool of  claim 1 , the second cutting element defining at least 75% of the nose region. 
     
     
         4 . The cutting tool of  claim 1 , the second cutting element defining at least 90% of the nose region. 
     
     
         5 . The cutting tool of  claim 1 , the nose region being defined by the second cutting element exclusive of the plurality of first cutting elements. 
     
     
         6 . The cutting tool of  claim 1 , further comprising:
 an additional second cutting element coupled to one of the plurality of blades and located in the nose region.   
     
     
         7 . The cutting tool of  claim 6 , the second cutting element and the additional second cutting element being positioned at same axial and radial positions on different ones of the plurality of blades. 
     
     
         8 . The cutting tool of  claim 1 , the second cutting element being one or more of:
 at least four (4) millimeters larger than the at least one of the plurality of first cutting elements;   at least two (2) industry-standard sizes larger than the at least one of the plurality of first cutting elements; or   between 15% and 300% larger in diameter than the at least one of the plurality of first cutting elements.   
     
     
         9 . The cutting tool of  claim 1 , the second cutting element having a diameter substantially larger than a diameter of each of the plurality of first cutting elements positioned outside the nose region. 
     
     
         10 . An apparatus, comprising:
 a bit body;   a plurality of blades coupled to the bit body; and   a plurality of cutting elements each coupled to a corresponding one of the plurality of blades, the plurality of cutting elements defining a cutting profile having:
 a cone region nearest a central axis of the bit body; 
 a gage region furthest from the central axis; and 
 a nose region between the cone region and the gage region, the nose region having a radius substantially equal to a radius of at least one first cutting element of the plurality of cutting elements, and the cone region and the gage region each including at least one second cutting element of the plurality of cutting elements that has a different size, shape, or construction than the at least one first cutting element. 
   
     
     
         11 . The apparatus of  claim 10 , the nose region being substantially co-axial with the at least one first cutting element. 
     
     
         12 . The apparatus of  claim 10 , the at least one first cutting element having an outer extent substantially defining the nose region. 
     
     
         13 . The apparatus of  claim 10 , each of at least one first cutting elements being one or more of:
 at least four (4) millimeters different in diameter than each of the at least one second cutting elements;   between 15% and 300% larger in diameter than each of the at least one second cutting elements; or   at least two (2) industry-standard sizes different than each of the at least one second cutting elements.   
     
     
         14 . The apparatus of  claim 10 , at least two of the plurality of cutting elements having same radial and axial positions on separate ones of the plurality of blades. 
     
     
         15 . The apparatus of  claim 10 , at least two of the plurality of cutting elements having differing back rake or side rake. 
     
     
         16 . The apparatus of  claim 10 , each of the plurality cutting elements, except for the at least one first cutting element, being of a same size. 
     
     
         17 . A method, comprising:
 urging a bit toward a downhole end of a wellbore, the bit comprising a plurality of cutting elements collectively defining a cutting profile having a nose region between cone and gage regions, a radius of the nose region equal to, and co-radial with, a first set of one or more of the plurality of cutting elements, and a second set of the plurality of cutting elements being positioned within the cone and gage regions and having a smaller diameter than the first set of one or more of the plurality of cutting elements; and   dislodging material from the wellbore by rotating the bit.   
     
     
         18 . The method of  claim 19 , dislodging material from the wellbore including at least one of:
 dislodging scale; or   dislodging subterranean formation.   
     
     
         19 . The method of  claim 19 , the first set of the one or more of the plurality of cutting elements including more than one cutting element. 
     
     
         20 . The method of  claim 19 , the second set of the plurality of cutting elements including more cutting elements than the first set of the one or more of the plurality of cutting elements.