Rotary drill bit including polycrystalline diamond cutting elements
View Patent ↗Embodiments relate to methods of fabricating PCD materials by subjecting a mixture that exhibits a broad diamond particle size distribution to an HPHT process, PCD materials so-formed, and PDCs including a polycrystalline diamond table comprising such PCD materials. In an embodiment, a PCD material includes a plurality of bonded diamond grains that exhibit a substantially unimodal diamond grain size distribution characterized, at least in part, by a parameter θ that is less than about 1.0. θ = x 6 · σ , where x is the average grain size of the substantially unimodal diamond grain size distribution, and σ is the standard deviation of the substantially unimodal diamond grain size distribution.
1. A drill bit, comprising:
a bit body configured to engage a subterranean formation, the bit body including a plurality of blades, each of the plurality of blades including a plurality of polycrystalline diamond cutting elements, at least one of the plurality of polycrystalline diamond cutting elements including a polycrystalline diamond material including:
a plurality of bonded diamond grains, the plurality of bonded diamond grains exhibiting a substantially unimodal diamond grain size distribution characterized, at least in part, by a parameter θ that is about 0.25 to about 1.0; and
wherein:
θ
=
x
6
·
σ
;
x is the average grain size of the substantially unimodal diamond grain size distribution, and is about 5 μm to about 30 μm; and
σ is the standard deviation of the substantially unimodal diamond grain size distribution.
2. The drill bit of claim 1 wherein the parameter θ is about 0.3 to about 0.9.
3. The drill bit of claim 1 wherein the parameter θ is about 0.3 to about 0.7.
4. The drill bit of claim 1 wherein the parameter θ is about 0.5 to about 0.7.
5. The drill bit of claim 1 wherein the parameter θ is about 0.3 to about 0.4.
6. The drill bit of claim 1 wherein σ is about 2 μm to about 15 μm.
7. The drill bit of claim 1 wherein σ is about 4 μm to about 10 μm, and the parameter θ is about 0.3 to about 0.7.
8. The drill bit of claim 1 wherein the polycrystalline diamond material exhibits a thermal stability that is at least about as thermally stable as a partially leached polycrystalline diamond material having a leach depth of about 60 μm to about 70 μm and a different diamond grain size distribution.
9. The drill bit of claim 1 wherein the at least one of the plurality of polycrystalline diamond cutting elements includes a substrate bonded to the polycrystalline diamond material.
10. The drill bit of claim 9 wherein the substrate comprises a cemented carbide material.
11. The drill bit of claim 1 wherein the polycrystalline diamond material is leached to a selected depth.
12. A drill bit, comprising:
a bit body configured to engage a subterranean formation, the bit body including a plurality of blades, each of the plurality of blades including a plurality of polycrystalline diamond cutting elements, at least one of the plurality of polycrystalline diamond cutting elements including a polycrystalline diamond material including:
a plurality of bonded diamond grains, the plurality of bonded diamond grains exhibiting a substantially unimodal diamond grain size distribution characterized, at least in part, by a parameter θ that is about 0.3 to about 0.7; and
wherein:
θ
=
x
6
·
σ
;
x is the average grain size of the substantially unimodal diamond grain size distribution and is about 10 μm to about 20 μm; and
σ is the standard deviation of the substantially unimodal diamond grain size distribution.
13. The drill bit of claim 12 wherein the parameter θ is about 0.5 to about 0.7.
14. The drill bit of claim 12 wherein the parameter θ is about 0.3 to about 0.4.
15. The drill bit of claim 12 wherein x is about 12 μm to about 15 μm and σ is about 6 μm to about 8.5 μm.
16. The drill bit of claim 12 wherein σ is about 4 μm to about 10 μm.
17. The drill bit of claim 12 wherein the polycrystalline diamond material is leached to a selected depth.
18. A drill bit, comprising:
a bit body configured to engage a subterranean formation, the bit body including a plurality of blades, each of the plurality of blades including a plurality of polycrystalline diamond cutting elements, at least one of the plurality of polycrystalline diamond cutting elements including a polycrystalline diamond material including:
a plurality of bonded diamond grains defining a plurality of interstitial regions, the plurality of bonded diamond grains exhibiting a substantially unimodal diamond grain size distribution characterized, at least in part, by a parameter θ that is about 0.3 to about 0.9;
wherein:
θ
=
x
6
·
σ
;
x is the average grain size of the substantially unimodal diamond grain size distribution and is about 10 μm to about 20 μm;
σ is the standard deviation of the substantially unimodal diamond grain size distribution; and
a catalyst material is disposed in at least a portion of the plurality of interstitial regions.
19. The drill bit of claim 18 wherein the polycrystalline diamond material is leached to a selected depth.
20. The drill bit of claim 18 wherein the catalyst material includes a metal-solvent catalyst or a carbonate catalyst.