Degradable Balls for Use in Subterranean Applications

• US 20130292123A1
• Filed: 05/31/2013
• Published: 11/07/2013
• Est. Priority Date: 02/11/2009
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Fripp, Michael Linley, Liang, Feng, Fulton, Dwight, Murphree, Zachary Ryan, Walton, Zachary William
• Granted Patent: US 9,260,935 B2
• Time in Patent Office: Days
• US Class Current: 166/308.1
• CPC Class Codes: C08J 2367/04 Polyesters derived from hydroxy carboxylic acids, e.g. lactones C08J2367/06 takes precedence
• CPC Class Codes: C08J 3/201 Pre-melted polymers
• CPC Class Codes: C08K 9/00 Use of pretreated ingredients
• CPC Class Codes: C08L 101/16 the macromolecular compounds being biodegradable
• CPC Class Codes: C09D 167/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C09D167/06 takes precedence
• CPC Class Codes: C09K 2208/08 Fiber-containing well treatment fluids
• CPC Class Codes: C09K 8/03 Specific additives for general use in well-drilling compositions
• CPC Class Codes: C09K 8/426 for plugging
• CPC Class Codes: C09K 8/50 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 Class Codes: C09K 8/516 characterised by their form or by the form of their components, e.g. encapsulated material
• CPC Class Codes: C09K 8/68 containing organic compounds
• CPC Class Codes: E21B 33/12 Packers; Plugs used for cementing E21B33/134, E21B33/16
• CPC Class Codes: E21B 33/138 Plastering the borehole wall; Injecting into the formation
• CPC Class Codes: E21B 34/142 unsupported or free-falling elements, e.g. balls, plugs, darts or pistons

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.

Claims

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.

17. A method comprising:

introducing a degradable ball according to one of claims 1-16 into a wellbore penetrating a subterranean formation;

seating the degradable ball in a baffle arranged within the wellbore, and thereby reducing a fluid flow through the baffle and defining an upper segment of the wellbore and a lower segment of the wellbore;

treating the upper segment of the wellbore; and

degrading the degradable ball and thereby returning fluid connectivity between the upper segment of the wellbore and the lower segment of the wellbore.

18. The method of claim 17, wherein treating the upper segment of the wellbore comprises introducing a treatment fluid at a pressure sufficient to create or extend at least one fracture in the subterranean formation adjacent to the upper segment of the wellbore.

19. The method of claim 17, wherein treating the upper segment of the wellbore comprises matrix acidizing the upper segment of the wellbore with a treatment fluid comprising a reactive fluid at a pressure below that required to create or extend at least one fracture in the subterranean formation adjacent to the upper segment of the wellbore.

20. A method comprising:

introducing a degradable ball according to one of claims 1-16 into a wellbore penetrating a subterranean formation and having a wellbore tool arranged therein, wherein the wellbore tool is configured to receive the degradable ball;

seating the degradable ball on the wellbore tool and thereby reducing the fluid flow through at least a portion of the wellbore tool;

applying a differential pressure across the degradable ball seated on the wellbore tool and thereby actuating the wellbore tool; and

degrading the degradable ball.

21. The method of claim 20, wherein the wellbore tool is a packer assembly and actuating the wellbore tool comprises engaging one or more packer elements of the packer assembly with an inner wall of the wellbore.

22. The method of claim 20, wherein the wellbore tool is a sliding sleeve and actuating the wellbore tool comprises axially moving the sliding sleeve within the wellbore.

23. The method of claim 20, wherein the wellbore tool is a crossover tool and actuating the wellbore tool comprises opening or closing at least one flow path across the crossover tool.

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.