Degradable balls for use in subterranean applications

Patent metadata

Field	Value
Publication number	US-9926483-B2
Application number	US-201614988421-A
Country	US
Kind code	B2
Filing date	Jan 5, 2016
Priority date	Feb 11, 2009
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

Degradable balls for downhole use may include an incompliant degradable polymer and a compliant filler material, the incompliant degradable polymer having an elastic modulus of about 2 GPa or greater, and the compliant filler material having an elastic modulus of less than about 2 GPa. Such degradable balls may be useful in sealing segments of a wellbore and actuating wellbore tools.

First claim

The invention claimed is:

1. A degradable ball for downhole use, the degradable ball comprising: an incompliant degradable polymer and a compliant filler material, the incompliant degradable polymer having an elastic modulus of about 2 GPa or greater, and the compliant filler material having an elastic modulus of less than about 2 GPa.

2. The degradable ball of claim 1 , wherein the incompliant degradable polymer comprises at least one selected from the group consisting of poly(glycolic acid), crystalline poly(lactic acid), semi-crystalline poly(lactic acid), a polyhydroxyalkonate, poly(hydroxybutyrate), an aliphatic polyester, a polycarbonate, an aliphatic polycarbonate, a polyorthoester, polyethylene terephthalate, a copolymer thereof, and a blend thereof.

3. The degradable ball of claim 1 , wherein the compliant filler material comprises at least one selected from the group consisting of a vulcanized rubber particle, a rubber fiber, a thermoplastic particle, a thermoplastic fiber, a hollow glass sphere, a hollow ceramic sphere, a hollow metal sphere, a hollow thermoplastic sphere, a particulate of a compliant degradable polymer, and any combination thereof.

4. The degradable ball of claim 1 , wherein the compliant filler material comprises a plurality of particulates having an average diameter of about 50 nm to about 500 nm.

5. The degradable ball of claim 1 , wherein the compliant filler material comprises a plurality of particulates having an average diameter of about 0.5 microns to about 1 mm.

6. The degradable ball of claim 1 , wherein the compliant filler material comprises a plurality of particulates having a surface modification.

7. The degradable ball of claim 1 , wherein the compliant filler is present in an amount of about 0.5% to about 50% by weight of the degradable ball.

8. The degradable ball of claim 1 , wherein the degradable ball further comprises at least one selected from the group consisting of a degradation accelerator, a degradable material, a plasticizer, a filler material, and any combination thereof.

9. The degradable ball of claim 1 , wherein the degradable ball has a structure selected from the group consisting of a layered structure, a core-shell structure, and a hybrid thereof.

10. The degradable ball of claim 1 , wherein the degradable ball has a diameter of about 1 inch to about 4 inches.

11. A degradable ball for downhole use, the degradable ball comprising:
a core comprising a first incompliant degradable polymer having an elastic modulus of about 2 GPa or greater; and
at least one shell disposed about the core, the shell comprising at least one selected from the group consisting of a degradable compliant polymer; a second incompliant degradable polymer and a compliant filler material; a second incompliant degradable polymer and a degradable compliant polymer; and any combination thereof, the compliant filler material and the degradable compliant polymer each having an elastic modulus of less than about 2 GPa, and the second and third incompliant degradable polymers each having an elastic modulus of about 2 GPa or greater.

12. The degradable ball of claim 11 , wherein the compliant filler material comprises a plurality of particulates having an average diameter of about 50 nm to about 500 nm.

13. The degradable ball of claim 11 , wherein the compliant filler material comprises a plurality of particulates having an average diameter of about 0.5 microns to about 1 mm.

14. The degradable ball of claim 11 , wherein degradable ball further comprises at least one selected from the group consisting of a degradation accelerator, a degradable material, a plasticizer, a filler material, and any combination thereof.

15. The degradable ball of claim 11 , wherein the compliant filler comprises a plurality of particulates having a surface modification.

16. The degradable ball of claim 11 , wherein the compliant filler is present in an amount of about 0.5% to about 50% by weight of the degradable ball.

Assignees

• Halliburton Energy Services Inc

Inventors

• Murphree Zachary Ryan
• Fripp Michael Linley
• Walton Zachary William
• Liang Feng
• Fulton Dwight

Classifications

• C08J3/201 Primary

  Pre-melted polymers · CPC title

• C08L101/16

  the macromolecular compounds being biodegradable · CPC title

• C09K2208/08

  Fiber-containing well treatment fluids · CPC title

• C09K8/03

  Specific additives for general use in well-drilling compositions · CPC title

• C09K8/50

  Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls (compositions for consolidating loose sand or the like around wells C09K8/56) · CPC title