Device and method to seal boreholes

• US 20040194971A1
• Filed: 05/21/2004
• Published: 10/07/2004
• Est. Priority Date: 01/26/2001
• Status: Active Grant

• Current Assignee: EzTech Limited, Weatherford Technology Holdings, LLC (Weatherford International PLC)
• Original Assignee: E2tech Limited
• Inventors: Thomson, Neil
• Granted Patent: US 7,228,915 B2
• Time in Patent Office: Days
• US Class Current: 166/387
• CPC Class Codes: E21B 33/1208 characterised by the construction of the sealing or packing means E21B33/1277 takes precedence
• CPC Class Codes: E21B 33/14 for cementing casings into boreholes
• CPC Class Codes: E21B 43/103 of expandable casings, screens, liners, or the like
• CPC Class Codes: Y10S 277/934 Seal swells when wet
• CPC Class Codes: Y10S 277/944 Elastomer or plastic

Abstract

Apparatus and methods are described that are particularly suited for creating a seal in a borehole annulus. In one embodiment, an outer surface 10s of an expandable conduit (10) is provided with a formation (20) that includes an elastomeric material (e.g. a rubber) that can expand and/or swell when the material comes into contact with an actuating agent (e.g. water, brine, drilling fluid etc.). The expandable conduit (10) is located inside a second conduit (e.g. a pre-installed casing, liner or open borehole) and radially expanded. The actuating agent can be naturally occurring in the borehole or can be injected or pumped therein to expand or swell the elastomeric material to create the seal.

Claims

1. A seal for use in a borehole, the seal comprising an elastomeric material that is capable of expanding or swelling upon contact with an actuating agent.

2. A seal according to claim 1, wherein the elastomeric material comprises a rubber.

4. A seal according to any preceding claim, wherein the actuating agent comprises a water- or mineral-based oil or water.

5. A seal according to any preceding claim, wherein the actuating agent is naturally occurring downhole, or is injected or pumped into the borehole.

6. A seal according to any one of claims 1 to 4, wherein a container of the actuating agent is located at or near the elastomeric material where the container bursts upon radial expansion of the conduit.

7. A seal according to any preceding claim, wherein the elastomeric material is applied to an outer surface of a conduit.

8. A seal according to claim 7, wherein the conduit is capable of being radially expanded.

9. A seal according to claim 7 or claim 8, wherein the elastomeric material is applied at two or more axially spaced-apart locations on the conduit.

10. A seal according to any one of claims 7 to 9, wherein the conduit is radially expanded.

11. A seal according to claim 10, wherein the conduit is located in a second conduit before being radially expanded.

12. A seal according to any preceding claim, wherein the elastomeric material is at least partially covered or encased in a non-swelling and/or non-expanding elastomeric material, or a non-swelling polymer.

13. A seal according to any preceding claim, wherein the elastomeric material swells upon contact with the actuating fluid due to absorption of the fluid by the material.

14. A seal according to any preceding claim, wherein the elastomeric material can expand through chemical attack resulting in a breakdown of cross-linked bonds.

3. A seal according to either preceding claim, wherein the elastomeric material is NITRILE™

, VITON™

, AFLAS™

, Ethylene-propylene rubbers (EPM or EPDM) or KALREZ™

.

15. A method of creating a seal in a borehole, the method comprising the steps of providing an elastomeric material in the borehole and exposing the material to an actuating agent that causes the elastomeric material to expand.

16. A method according to claim 15, including the additional step of applying the elastomeric material to an outer surface of a conduit.

17. A method according to claim 16, including the additional step of locating the conduit within a second conduit.

18. A method according to claim 16 or claim 17, wherein the method includes the additional step of applying a radial expansion force to the conduit.

19. A method according to any one of claim 15 to 18, wherein the method includes the additional step of injecting or pumping the actuating agent into the borehole.