Shaped cutters
Embodiments of the present invention provides cutting elements for use on rotary drill bits for drilling subterranean formations. More specifically, the present disclosure relates to cutting elements having a shaped upper surface including at least one spoke for cutting and/or failing subterranean formations during drilling. The present disclosure also relates to drill bits incorporating one or more of such cutting elements.
1. A cutting element for drilling subterranean formations, comprising:
a cylindrical substrate;
a superabrasive table positioned on the cylindrical substrate, the superabrasive table comprising:
a cutting face having a planar central region and an outer circumferential cutting edge;
a plurality of spokes extending radially outward from the central region to the edge of the cutting face; and
a plurality of depressions, each depression extending between adjacent spokes and from a periphery of the central region to the outer circumferential cutting edge of the cutting face,
wherein each spoke comprises an interior region adjacent the central region, an outer region adjacent the edge of the cutting face, and an upper surface extending therebetween,
wherein the upper surface of each spoke is flat across the entire width of the spoke and the upper surface is co-planar with the central region,
wherein the upper surface of each spoke has an upper surface width that decreases along an entire distance from the interior region to the outer region.
2. The cutting element of claim 1 , wherein each spoke is continuous with the central region.
3. The cutting element of claim 1 , wherein each depression has a depth that decreases from an interior radial region to an outer radial region.
4. The cutting element of claim 3 , wherein the depression merges with the outer region of the spokes adjacent the cutting edge.
5. The cutting element of claim 3 , wherein the depression merges with the interior region of the spokes adjacent the central region.
6. The cutting element of claim 1 , wherein the cutting face does not include a planar outer lateral circumferential portion adjacent the cutting edge of the cutting face.
7. The cutting element of claim 1 , wherein each spoke includes sidewalls on opposing sides of the upper surface, each of the sidewalls extending from the upper surface to the depression.
8. The cutting element of claim 7 , wherein each sidewall has a slope that increases from the interior region to the outer region.
9. The cutting element of claim 7 , wherein each sidewall increases in height from the interior region to the outer region.
10. The cutting element of claim 7 , wherein each sidewall decreases in height from the interior region to the outer region.
11. The cutting element of claim 7 , comprising at least four spokes equidistantly spaced on the cutting face.
12. The cutting element of claim 11 , wherein each of the at least four spokes are symmetrically arranged on the cutting face, wherein each of the at least four spokes are continuous and planar with the central region.
13. The cutting element of claim 11 , wherein the at least four spokes comprise from 25% to 80% of the total surface area of the cutting face.
14. The cutting element of claim 1 , wherein an interior region of each depression forms an obtuse angle between adjacent spokes.
15. The cutting element of claim 1 , wherein an interior region of each depression forms an angle ranging from 90° to 180° between adjacent spokes.
16. The cutting element of claim 1 , wherein the superabrasive table comprises a chamfered region between the edge of the cutting face and a sidewall of the cylindrical substrate.
17. The cutting element of claim 1 , comprising at least three spokes equidistantly spaced on the cutting face.
18. The cutting element of claim 17 , wherein the cutting element is a low-profile cutter have a high back rake angle.
19. A drill bit, comprising:
a body having a structure for connection to a drill string;
at least one cutting element mounted to the body at an end thereof opposite the structure, the at least one cutting element comprising:
a cylindrical substrate;
a superabrasive table positioned on the cylindrical substrate, the superabrasive table comprising:
a cutting face having a planar central region and an outer circumferential cutting edge;
a plurality of spokes extending radially outward from the central region to the edge of the cutting face; and
a plurality of depressions, each depression extending between adjacent spokes and from a periphery of the central region to the outer circumferential cutting edge of the cutting face,
wherein each spoke comprises an interior region adjacent the central region, an outer region adjacent the edge of the cutting face, and an upper surface extending therebetween,
wherein the upper surface of each spoke is flat across the entire width of the spoke and the upper surface is co-planar with the central region,
wherein the upper surface of each spoke has an upper surface width that decreases along an entire distance from the interior region to the outer region.
20. The drill bit of claim 19 , wherein each pair of adjacent spokes of the plurality of spokes is separated by at least one depression of the plurality of depressions.
21. The drill bit of claim 19 , wherein the body has a face and a central axis and a plurality of blades disposed on the face, each blade having a row of cutters mounted thereon, wherein at least one of the cutters comprises the cutting element, and wherein the cutting element is clocked relative to a kerf region formed by rotationally preceding cutters.
22. The drill bit of claim 19 , wherein the body has a face and a central axis and a plurality of blades disposed on the face, each blade having a row of cutters mounted thereon, wherein at least one of the cutters comprises the cutting element, and wherein the spokes are oriented perpendicularly relative to a surface formation to be failed.
23. The drill bit of claim 19 , wherein the superabrasive table has regions of maximum thickness where the spokes meet the edge of the cutting face.
24. A cutting element for drilling subterranean formations, comprising:
a cylindrical substrate;
a superabrasive table positioned on the cylindrical substrate, the superabrasive table comprising:
a planar cutting face; and
a planar polygonal member disposed on and parallel to the cutting face, the polygonal member having a central region and a plurality of spokes, each of the spokes being raised in relation to the cutting face;
wherein each spoke extends from the central region to a periphery of the cutting face,
wherein each spoke comprises an interior region adjacent the central region, an outer region adjacent an edge of the cutting face, and an upper surface extending therebetween,
wherein the upper surface of each spoke is flat across the entire width of the spoke and the upper surface is co-planar with the central region,
wherein the upper surface of each spoke has an upper surface width that decreases along an entire distance from the interior region to the outer region.
25. The cutting element of claim 24 , wherein the polygonal member is in the shape of a star.
26. The cutting element of claim 24 , wherein the plurality of spokes comprises at least four spokes equidistantly spaced on the cutting face, wherein the cutting face is exposed in a region between each pair of adjacent spokes.
27. The cutting element of claim 26 , wherein each of the at least four spokes further comprises sidewalls on opposing sides of the upper surface.