Corrodible wellbore plugs and systems and methods including the same

Patent metadata

Field	Value
Publication number	US-9790762-B2
Application number	US-201414570758-A
Country	US
Kind code	B2
Filing date	Dec 15, 2014
Priority date	Feb 28, 2014
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

Corrodible wellbore plugs, systems and methods are disclosed herein. The methods include flowing a corrodible wellbore plug that is at least partially formed from a corrodible metal to a downhole location within a wellbore conduit and retaining the corrodible wellbore plug at the downhole location by operatively engaging an engagement structure with a wellbore tubular that defines the wellbore conduit. The methods include pressurizing a portion of the wellbore conduit uphole from the corrodible wellbore plug and flowing a corrosive reservoir fluid from the subterranean formation into contact with the corrodible metal to release the corrodible wellbore plug from the downhole location. The methods also may include removing the wellbore plug without utilizing a drill-out process. The systems include a corrodible wellbore plug that includes a plug body and a retention mechanism, which includes a slip ring formed from the corrodible metal and that includes the engagement structure.

First claim

The invention claimed is:

1. A method of completing a hydrocarbon well that extends within a subterranean formation that contains a naturally occurring corrosive reservoir fluid, the method comprising:
pressurizing a portion of a wellbore conduit that is uphole from a corrodible frac plug with a pressurizing fluid, wherein the wellbore conduit is defined by a wellbore tubular that extends within the subterranean formation, and further wherein the corrodible frac plug is retained at a downhole location within the wellbore conduit and includes:
(i) a flow-control device that is configured to permit a fluid flow therethrough in an uphole direction and to restrict the fluid flow therethrough in a downhole direction; and
(ii) a corrodible metallic portion that is formed from a corrodible metal that is selected to resist corrosion when in contact with the pressurizing fluid and to corrode responsive to contact with the corrosive reservoir fluid;
(iii) a reinforcing material that defines a plurality of reinforcing bodies that define a portion of the corrodible frac plug, wherein the reinforcing material does not corrode within the reservoir fluid, and wherein the corrodible metallic portion retains the plurality of reinforcing bodies within the corrodible frac plug; and

subsequent to the pressurizing, flowing the corrosive reservoir fluid from the subterranean formation through the flow-control device, wherein the flowing includes contacting the corrodible frac plug with the corrosive reservoir fluid to corrode the corrodible metal to disengage the plurality of reinforcing bodies from the corrodible frac plug and release the corrodible frac plug from the downhole location within the wellbore conduit.

2. The method of claim 1 , wherein the method further includes retaining the corrodible frac plug within the wellbore conduit.

3. The method of claim 2 , wherein the retaining includes expanding a slip ring of the corrodible frac plug to operatively engage the slip ring with the wellbore tubular, wherein the slip ring is at least partially formed from the corrodible metal.

4. The method of claim 3 , wherein the retaining includes operatively engaging an engagement structure of the slip ring with the wellbore tubular, wherein the engagement structure at least one of:
(i) is operatively attached to the slip ring;
(ii) is at least partially embedded within the slip ring; and
(iii) coats a peripheral surface of the slip ring.

5. The method of claim 2 , wherein the method further includes forming, with a sealing element, a fluid seal between the corrodible frac plug and the wellbore tubular during the retaining.

6. The method of claim 2 , wherein the retaining includes at least one of:
(i) cold welding the corrodible frac plug to the wellbore tubular; and
(ii) galling the wellbore tubular with the corrodible frac plug to retain the corrodible frac plug within the wellbore conduit.

7. The method of claim 1 , wherein the method further includes stimulating the subterranean formation with the pressurizing fluid.

8. The method of claim 7 , wherein the stimulating includes perforating the wellbore tubular responsive to a pressure within the portion of the wellbore conduit that is uphole from the corrodible frac plug exceeding a threshold perforating pressure.

9. The method of claim 8 , wherein the perforating includes creating a first perforation within the wellbore tubular at a first location, wherein the method further includes sealing the first perforation with a ball sealer to re-pressurize the portion of the wellbore conduit that is uphole from the corrodible frac plug, and further wherein the method includes perforating the wellbore tubular to create a second perforation within the wellbore tubular at a second location that is uphole from the first location.

10. The method of claim 1 , wherein the method further includes generating turbulent flow within the corrosive reservoir fluid and in contact with the corrodible frac plug to accelerate corrosion of the corrodible metal.

11. The method of claim 1 , wherein the flowing the corrosive reservoir fluid includes heating the corrodible frac plug to a temperature of at least 100 degrees Celsius and exposing the corrodible frac plug to a pH of less than 4.5.

12. The method of claim 1 , wherein the flowing the corrosive reservoir fluid includes contacting the corrosive reservoir fluid with the corrodible frac plug at a pressure of at least 5 megapascals.

13. The method of claim 1 , wherein the corrosive reservoir fluid includes at least 1.0 mole percent carbon dioxide, and further wherein the flowing the corrosive reservoir fluid includes contacting the corrodible frac plug with the carbon dioxide.

14. The method of claim 1 , wherein the corrodible metallic portion defines a relief structure that is shaped to facilitate the separating.

15. A corrodible frac plug configured to be retained within a wellbore conduit and to regulate a fluid flow within the wellbore conduit, wherein the wellbore conduit extends within a subterranean formation that includes a naturally occurring corrosive reservoir fluid, the corrodible frac plug comprising:
a plug body that is shaped to be placed within the wellbore conduit; and a retention mechanism that is configured to selectively transition between a mobile conformation, in which the corrodible frac plug is free to translate within the wellbore conduit, and a retained conformation wherein the corrodible frac plug operatively engages a wellbore tubular that defines the wellbore conduit to retain the corrodible frac plug at a downhole location within the wellbore conduit, the retention mechanism comprising:
(a) a slip ring that defines a retracted conformation when the retention mechanism is in the mobile conformation and an expanded conformation when the retention mechanism is in the retained conformation, wherein the slip ring is formed from a corrodible metal that is selected to corrode responsive to contact with the corrosive reservoir fluid;
(b) an engagement structure, wherein the engagement structure is configured to operatively engage the wellbore tubular when the slip ring is in the expanded conformation; and
(c) a reinforcing material that defines a plurality of reinforcing bodies that define a portion of the corrodible frac plug, wherein the reinforcing material does not corrode within the reservoir fluid, and wherein the corrodible metal retains the plurality of reinforcing bodies within the corrodible frac plug.

16. The corrodible frac plug of claim 15 , wherein the retention mechanism further includes a cone and a mandrel, wherein the mandrel is configured to press the slip ring against the cone to transition the slip ring from the retracted conformation to the expanded conformation.

17. The corrodible frac plug of claim 16 , wherein at least one of:
(i) the cone is formed from a corrodible cone material that is selected to corrode responsive to contact with the corrosive reservoir fluid; and
(ii) the mandrel is formed from a corrodible mandrel material that is selected to corrode responsive to contact with the corrosive reservoir fluid.

18. The corrodible frac plug of claim 16 , wherein the mandrel is a hollow cylindrical mandrel that defines a mandrel conduit, and wherein the corrodible frac plug includes a turbulence-generating structure that is configured to generate turbulence within fluid flow through the mandrel conduit.

19. The corrodible frac plug of claim 15 , wherein the corrodible frac plug further includes a flow-control device that is conf

Assignees

• Tolman Randy C
• Hall Timothy J
• Exxonmobil Upstream Res Co

Inventors

• Tolman Randy C
• Hall Timothy J

Classifications

• E21B33/12 Primary

  Packers; Plugs (used for cementing E21B33/134, E21B33/16) · CPC title

• E21B33/1293

  with means for anchoring against downward and upward movement (E21B33/1291, E21B33/1295 take precedence) · CPC title

• E21B33/1208

  characterised by the construction of the sealing or packing means (E21B33/1277 takes precedence) · CPC title