Hybrid dissolvable plugs for sealing downhole casing strings

Patent metadata

Field	Value
Publication number	US-2023243231-A1
Application number	US-202318103247-A
Country	US
Kind code	A1
Filing date	Jan 30, 2023
Priority date	Jan 31, 2022
Publication date	Aug 3, 2023
Grant date	—

Abstract

A plug deployable into a wellbore having a casing string includes a sealing element including an outer sealing surface configured to extend outwardly from a central axis of the plug and sealingly press against a casing string when the plug is in the second configuration, and a slip including at least one slip body having a peripheral outer face oriented to face away from the central axis and towards the casing string, and one or more engagement members located on the outer face of the slip body wherein the one or more engagement members are configured to bite into the casing string when the plug is in the second configuration, wherein at least 40% of a total volume of the plug is formed from corrosion-selected materials and at least 30% of the total volume of the plug is formed from corrosion-resistant materials.

First claim

What is claimed is:

1 . A plug deployable as part of a tool string into a wellbore having a casing string positioned therein, the plug comprising:
an annular sealing element comprising a radially outer sealing surface configured to extend outwardly from a central axis of the plug and sealingly press against an inner surface of the casing string when the plug is in the second configuration; a slip extending comprising at least one slip body having a peripheral outer face oriented to face away from the central axis and toward the casing string, and one or more engagement members located on the outer face of the slip body wherein the one or more engagement members are configured to bite into the casing string when the plug is in the second configuration to thereby resist axial movement of the slip relative to the casing string; and a nose having an annular nose body located at a downhole end of the plug, wherein the nose is configured to apply an axially directed force against the sealing element to force the sealing surface of the sealing element into sealing engagement with the casing string when the plug is in the second configuration; wherein the annular nose body of the nose comprises a corrosion-selected material and is configured to dissolve following a predetermined delay period, and the one or more slip bodies of the slip are formed from a corrosion-resistant material.

2 . The plug according to claim 1 , wherein the annular nose body comprises at least one of a magnesium alloy and an aluminum alloy.

3 . The plug according to claim 1 , wherein the annular nose body comprises a corrosion-resistant coating encapsulating the corrosion-selected material.

4 . The plug according to claim 1 , further comprising:
an elongate mandrel having a first end, a second end longitudinally opposite the first end, and an outer surface extending from the first end to the second end, wherein the first end is configured to connect to a setting tool of the tool string for actuating the plug from a first configuration to a second configuration; and a slip retainer having an annular retainer body extending around the outer surface of the mandrel and having an annular engagement surface in contact with an end of the slip, and wherein the slip is positioned axially between the slip retainer and the sealing element; wherein the annular retainer body comprises a corrosion-selected material configured to dissolve following a predetermined delay period.

5 . The plug according to claim 1 , further comprising:
a ramp having an annular ramp body having an inclined engagement surface extending at an acute angle radially outwards from the central axis, and wherein a radially inner surface of the at least one slip body of the slip is positioned on the inclined engagement surface when the plug is in the second configuration; wherein the annular ramp body comprises a corrosion resistant material.

6 . The plug according to claim 1 , wherein at least 40% of a total volume of the plug is formed from corrosion-selected materials and at least 30% of the total volume of the plug is formed from corrosion-resistant materials.

7 . The plug according to claim 6 , wherein more than 50% of a total volume of the plug is formed from corrosion-selected materials.

8 . A plug deployable as part of a tool string into a wellbore having a casing string positioned therein, the plug comprising:
an annular sealing element comprising a radially outer sealing surface configured to extend outwardly from a central axis of the plug and sealingly press against an inner surface of the casing string when the plug is in the second configuration; and a slip comprising at least one slip body having a peripheral outer face oriented to face away from the central axis and towards the casing string, and one or more engagement members located on the outer face of the slip body wherein the one or more engagement members are configured to bite into the casing string when the plug is in the second configuration to thereby resist axial movement of the slip relative to the casing string; wherein at least 40% of a total volume of the plug is formed from corrosion-selected materials and at least 30% of the total volume of the plug is formed from corrosion-resistant materials.

9 . The plug according to claim 8 , wherein more than 50% of a total volume of the plug is formed from corrosion-selected materials.

10 . The plug according to claim 8 , wherein at least 60% of a total volume of the plug is formed from corrosion-selected materials.

11 . The plug according to claim 8 , further comprising:
a nose having an annular nose body located at a downhole end of the plug, wherein the nose is configured to apply an axially directed force against the sealing element to force the sealing surface of the sealing element into sealing engagement with the casing string when the plug is in the second configuration; wherein the annular nose body of the nose comprises a corrosion-selected material.

12 . The plug according to claim 8 , wherein the corrosion-selected materials comprise at least one of a magnesium alloy and an aluminum alloy.

13 . The plug according to claim 8 , wherein the corrosion-selected materials are encapsulated in a corrosion-resistant coating.

14 . The plug according to claim 8 , further comprising:
an elongate mandrel having a first end, a second end longitudinally opposite the first end, and an outer surface extending from the first end to the second end, wherein the first end is configured to connect to a setting tool of the tool string for actuating the plug from a first configuration to a second configuration; and a slip retainer having an annular retainer body extending around the outer surface of the mandrel and having an annular engagement surface in contact with an end of the slip, and wherein the slip is positioned axially between the slip retainer and the sealing element; wherein the annular retainer body comprises a corrosion-selected material configured to dissolve following a predetermined delay period.

15 . The plug according to claim 8 , further comprising:
a ramp having an annular ramp body having an inclined engagement surface extending at an acute angle radially outwards from the central axis, and wherein a radially inner surface of the at least one slip body of the slip is positioned on the inclined engagement surface when the plug is in the second configuration; wherein the annular ramp body comprises a corrosion resistant material.

16 . A method for preparing a cased subterranean wellbore for the production of subterranean fluids, the method comprising:
(a) deploying a tool string to a desired location within the casing string positioned in the wellbore, the tool string comprising one or more perforating guns, a setting tool, and a downhole-deployable plug having a central axis, wherein the plug comprises an annular sealing element, a slip comprising at least one slip body having a radially outer face, a nose comprising an annular nose body located at a downhole end of the plug, and one or more engagement members located on the outer face of the slip body; (b) actuating the setting tool with the tool string located at the desired location whereby the plug is actuated from a first configuration to a second configuration in which the one or more engagement members of the slip attach to the casing string and a radially outer sealing surface of the sealing element enters into sealing contact with the casing string such that fluid flow across the plug is restricted in at least one axial direction; (c) ac

Assignees

• G&H Diversified Mfg Lp

Inventors

• Zakharia Steven
• Magill Joshua
• Ward Ryan

Classifications

• E21B23/0411

  specially adapted for anchoring tools or the like to the borehole wall or to well tube · CPC title

• E21B33/167

  Cementing plugs provided with anti-rotation mechanisms, e.g. for easier drill-out · CPC title

• E21B23/06 Primary

  for setting packers · CPC title

• E21B33/1293

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

• E21B33/128

  with a member expanded radially by axial pressure (E21B33/122, E21B33/124 take precedence) · CPC title