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, comprising:
a substantially cylindrical substrate;
a superabrasive table positioned on the cylindrical substrate, the superabrasive table comprising:
a cutting face having a substantially planar portion surrounding a central recess, the planar portion extending laterally to an outer circumferential edge; and
at least one spoke disposed on the cutting face, each spoke extending radially from a periphery of the recess to the outer circumferential edge;
wherein the central recess comprises a convex member.
2. The cutting element of claim 1 , wherein each spoke comprises an upper surface having an interior region adjacent the periphery of the recess and an outer region adjacent the edge of the cutting face, wherein the upper surface has an upper surface width that decreases from the interior region to the outer region.
3. The cutting element of claim 1 , wherein each spoke is raised in relation to the planar portion of the cutting face.
4. The cutting element of claim 1 , wherein each spoke comprises an interior region adjacent the periphery of the recess and an outer region adjacent the edge of the cutting face, wherein each spoke has a height that increases from the interior region to the outer region, and wherein each spoke has a maximum height at the outer region.
5. The cutting element of claim 1 , wherein each spoke comprises an interior region adjacent the periphery of the recess, an outer region adjacent the edge of the cutting face, and an upper lateral spoke surface extending therebetween, wherein each spoke comprises sidewalls on opposing sides of the upper lateral spoke surface, each of the sidewalls extending from the upper lateral spoke surface to the planar portion of the cutting face.
6. The cutting element of claim 5 , wherein each of the sidewalls are transverse relative to the upper lateral spoke surface of each spoke and the planar portion of the cutting face, wherein each sidewall increases in height from the interior region to the outer region.
7. The cutting element of claim 1 , comprising at least four spokes equidistantly spaced on the cutting face, wherein the planar portion is divided into four separate planar portions, each pair of adjacent spokes being separated by a respective planar portion.
8. 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.
9. A cutting element for drilling subterranean formations, comprising:
a substantially cylindrical substrate;
a superabrasive table positioned on the cylindrical substrate, the superabrasive table comprising:
a cutting face having a substantially 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, 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 a ratio of an upper surface width at the interior region to the upper surface width at the outer region ranges from 0.5:1 to 2:1, wherein the upper surface of each of the spokes is flat and co-planar with the central region; 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.
10. The cutting element of claim 9 , wherein the upper surface of each spoke is substantially co-planar and continuous with the central region.
11. The cutting element of claim 9 , wherein the upper surface of each spoke has a width that is substantially constant from the interior region to the outer region.
12. The cutting element of claim 9 , wherein the upper surface of each spoke has a width that decreases from the interior region to the outer region.
13. The cutting element of claim 9 , wherein each depression has a depth that increases from an interior radial region to an outer radial region, wherein each depression merges with the cutting edge.
14. The cutting element of claim 9 , wherein each depression merges with a portion of one or more spokes at the interior region adjacent the central region.
15. The cutting element of claim 9 , wherein the cutting face does not include a substantially planar outer lateral circumferential portion adjacent the cutting edge of the cutting face.
16. The cutting element of claim 9 , wherein each spoke increases in height from the interior region to the outer region, and wherein the spoke has a maximum height at the outer region.
17. The cutting element of claim 9 , wherein each spoke includes sidewalls on opposing sides of the upper surface, each of the sidewalls extending from the upper surface to the depression.
18. The cutting element of claim 17 , wherein each sidewall extends from the upper surface to the depression of an associated spoke at a transverse angle.
19. The cutting element of claim 9 , comprising at least four spokes equidistantly spaced on the cutting face, 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 co-planar with the central region.
20. The cutting element of claim 9 , wherein the upper surface has a minimum upper surface width in an intermediate region between the central region and the outer region.
21. The cutting element of claim 9 , wherein an interior region of each depression forms an angle ranging from 45 ° to 180 ° between adjacent spokes.
22. The cutting element of claim 9 , wherein each depression has a depth that is constant or decreases from an interior radial region to an outer radial region.
23. The cutting element of claim 22 , wherein the cutting face includes a substantially planar outer lateral circumferential portion adjacent the cutting edge of the cutting face.
24. The cutting element of claim 22 , 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 has a minimum upper surface width in an intermediate region between the central region and the outer region.
25. A cutting element for drilling subterranean formations, comprising:
a substantially cylindrical substrate;
a superabrasive table positioned on the cylindrical substrate, the superabrasive table comprising:
an asymmetric cutting face having a substantially 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, each spoke comprises an interior region adjacent the central region, an outer region adjacent the cutting edge of the cutting face, and an upper surface extending therebetween, wherein each spoke includes sidewalls on opposing sides of the upper surface; 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; p 1 wherein each spoke has a leading sidewall and a trailing sidewall and, when taken in the clockwise direction, the leading sidewall has a shorter length than the trailing sidewall.
26. The cutting element of claim 25 , wherein each spoke has a leading sidewall and a trailing sidewall and, when taken in the clockwise direction, the leading sidewall has a longer length than the trailing sidewall.
27. The cutting element of claim 25 , wherein the sidewalls of each of the spokes are not mirror images of each other.
28. The cutting element of claim 25 , wherein at least one of the sidewalls is convex.
29. The cutting element of claim 25 , wherein at least one of the sidewalls is concave.
30. The cutting element of claim 25 , wherein the upper surface of each spoke is substantially co-planar continuous with the central region.
31. The cutting element of claim 25 , comprising at least four spokes spaced apart on the cutting face, wherein each of the at least four spokes are continuous and co-planar with the central region.