Hybrid dissolvable plugs for sealing downhole casing strings

Patent metadata

Field	Value
Publication number	US-12540525-B2
Application number	US-202318103247-A
Country	US
Kind code	B2
Filing date	Jan 30, 2023
Priority date	Jan 31, 2022
Publication date	Feb 3, 2026
Grant date	Feb 3, 2026

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 elastomeric 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 comprising at least one slip body formed from a non-corrosive material configured to resist corrosion when exposed to conditions in the wellbore, wherein the slip body has 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 non-corrosive 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; 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 receiving an axially directed force transferrable through the mandrel and against the sealing element to force the sealing surface of the sealing element, which surrounds the mandrel, into sealing engagement with the casing string; and a nose coupled to the second end of the mandrel and having an annular nose body located at a downhole end of the plug and formed from a corrosion-selected material configured to dissolve when exposed to conditions in the wellbore following a predetermined delay period, 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; wherein the plug comprises:
a run-in configuration having a run-in maximum outer diameter configured to travel along and within the casing string;
a first deployed configuration having a deployed maximum outer diameter that is greater than the run-in maximum outer diameter whereby an axially directed force applied by the nose via the mandrel causes radial expansion of the slip toward contact with the casing string so as to restrict relative rotation between the slip and the casing string, wherein the plug further comprises a lock ring having rachet teeth configured to engage with corresponding teeth formed on the mandrel so as to restrict relative movement between the mandrel and the lock ring, and wherein in the first deployed configuration relative rotation is restricted between the nose and the casing string via an intermediate connection formed between the nose and the rotationally locked slip; and
a second deployed configuration in which the mandrel and the nose are dissolved but the slip remains in contact with the casing string restricting relative rotation therebetween.

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 non-corrosive coating encapsulating the corrosion-selected material.

4 . The plug according to claim 1 , further comprising:
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 first deployed configuration; wherein the annular ramp body comprises a non-corrosive 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 non-corrosive 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 elastomeric 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 a first deployed configuration; and a slip comprising at least one slip body formed from non-corrosive materials configured to resist corrosion when exposed to conditions in the wellbore, wherein the at least one slip body has 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 first deployed configuration to thereby resist axial movement of the slip relative to the casing string; 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 receiving an axially directed force transferrable through the mandrel and against the sealing element to force the sealing surface of the sealing element, which surrounds the mandrel, into sealing engagement with the casing string; wherein the plug comprises:
a run-in configuration having a run-in maximum outer diameter configured to travel along and within the casing string;
the first deployed configuration has a deployed maximum outer diameter that is greater than the run-in maximum outer diameter whereby an axially directed force applied through the mandrel causes radial expansion of the slip toward contact with the casing string so as to restrict relative rotation between the slip and the casing string, wherein the plug further comprises a lock ring having rachet teeth configured to engage with corresponding teeth formed on the mandrel so as to restrict relative movement between the mandrel and the lock ring, and wherein in the first deployed configuration relative rotation is restricted between the mandrel and the casing string via an intermediate connection formed between the mandrel and the rotationally locked slip; and
a second deployed configuration in which the mandrel is dissolved but the slip remains in contact with the casing string restricting relative rotation therebetween.

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 pl

Assignees

• G&H Diversified Mfg Lp

Inventors

• Zakharia Steven
• Magill Joshua
• Ward Ryan

Classifications

• E21B2200/08

  Down-hole devices using materials which decompose under well-bore conditions · CPC title

• E21B43/116

  Gun or shaped-charge perforators · CPC title

• E21B29/00

  Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground · CPC title

• E21B33/1208 Primary

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

• E21B23/0411

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