Plow-shaped cutting elements for earth-boring tools, earth-boring tools including such cutting elements, and related methods

1. A cutting element for an earth-boring tool, comprising:

a substrate; and

at least one volume of superabrasive material on the substrate, the at least one volume of superabrasive material including a first planar surface and a second planar surface oriented at an angle relative to the first planar surface and intersecting the first planar surface along an apex;

wherein the first planar surface has a first shape comprising more than half of a circle or more than half of an oval, the first shape having a first maximum diameter, the second planar surface has a second shape comprising more than half of a circle or more than half of an oval, the second shape having a second maximum diameter, and the apex has a length less than the first maximum diameter and the second maximum diameter, wherein notches extend in a lateral side surface of the at least one volume of superabrasive material on opposing sides adjacent the apex.

2. The cutting element of claim 1 , wherein the superabrasive material comprises at least one of polycrystalline diamond and cubic boron nitride.

3. The cutting element of claim 1 , wherein the at least one volume of superabrasive material comprises:

a first layer of superabrasive material on a first region of the substrate; and

a second layer of superabrasive material on a second region of the substrate.

4. The cutting element of claim 3 , wherein the first layer of superabrasive material and the second layer of superabrasive material are integral portions of a single volume of the superabrasive material.

5. The cutting element of claim 1 , wherein the apex is linear.

6. The cutting element of claim 1 , wherein the length of the apex is about 95% or less of each of the first maximum diameter and the second maximum diameter.

7. The cutting element of claim 6 , wherein the length of the apex is about 90% or less of each of the first maximum diameter and the second maximum diameter.

8. The cutting element of claim 7 , wherein the length of the apex is about 85% or less of each of the first maximum diameter and the second maximum diameter.

9. The cutting element of claim 1 , wherein the angle between the first planar surface and the second planar surface is between 90° and about 180°.

10. The cutting element of claim 9 , wherein the angle between the first planar surface and the second planar surface is between about 115° and about 175°.

11. The cutting element of claim 10 , wherein the angle between the first planar surface and the second planar surface is between about 130° and about 165°.

12. An earth-boring tool, comprising:

a body; and

at least one cutting element attached to the body, the at least one cutting element including at least one volume of superabrasive material on a substrate, the at least one volume of superabrasive material having a first planar surface and a second planar surface oriented at an angle relative to the first planar surface and intersecting the first planar surface along an apex, wherein the first planar surface has a first shape comprising more than half of a circle or more than half of an oval, the first shape having a first maximum diameter, the second planar surface has a second shape comprising more than half of a circle or more than half of an oval, the second shape having a second maximum diameter, and the apex has a length less than the first maximum diameter and the second maximum diameter, wherein notches extend in a lateral side surface of the at least one volume of superabrasive material on opposing sides adjacent the apex.

13. The earth-boring tool of claim 12 , wherein the earth-boring tool comprises a fixed-cutter rotary drill bit.

14. The earth-boring tool of claim 13 , wherein the fixed-cutter rotary drill bit comprises a coring bit having a generally cylindrical void defined at a center of the body.

15. The earth-boring tool of claim 14 , wherein the at least one cutting element is attached to the body at a location adjacent the generally cylindrical void, the at least one cutting element located and configured such that a lateral cutting edge of the at least one cutting element defined at a periphery of one of the first planar surface and the second planar surface remote from the apex will cut and define a core sample of a formation when the coring bit is used to drill through the formation.

16. The earth-boring tool of claim 12 , wherein the apex is linear.

17. The earth-boring tool of claim 16 , wherein the length of the apex is about 95% or less of each of the first maximum diameter and the second maximum diameter.

18. The earth-boring tool of claim 17 , wherein the angle between the first planar surface and the second planar surface is between about 115° and about 175°.

19. The earth-boring tool of claim 18 , wherein the angle between the first planar surface and the second planar surface is between about 130° and about 165°.

20. A method of forming an earth-boring tool, comprising:

selecting at least one cutting element to include at least one volume of superabrasive material on a substrate, the at least one volume of superabrasive material having a first planar surface and a second planar surface oriented at an angle relative to the first planar surface and intersecting the first planar surface along an apex, wherein the first planar surface has a first shape comprising more than half of a circle or more than half of an oval, the first shape having a first maximum diameter, the second planar surface has a second shape comprising more than half of a circle or more than half of an oval, the second shape having a second maximum diameter, and the apex has a length less than the first maximum diameter and the second maximum diameter, wherein notches extend in a lateral side surface of the at least one volume of superabrasive material on opposing sides adjacent the apex; and

attaching the at least one cutting element to a body of an earth-boring tool.