Eutectic alloy system for casing-casing annulus cement repair

Patent metadata

Field	Value
Publication number	US-12228010-B1
Application number	US-202418405571-A
Country	US
Kind code	B1
Filing date	Jan 5, 2024
Priority date	Jan 5, 2024
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

A method includes running a eutectic alloy system downhole in a wellbore including a first casing string and a second casing string therein, activating a differential valve tool within the second casing to generate a primary annular seal within a casing-casing annulus defined between the first casing string and second casing string, pumping a flushing fluid into the casing-casing annulus above the primary annular seal via a first ported collar, melting a eutectic alloy blanket into a molten alloy within the flushing fluid in the casing-casing annulus via a heater, solidifying the molten alloy to establish a supplemental seal above the primary annular seal in the casing-casing annulus between the first casing string and second casing string, and pumping cement into the casing-casing annulus above the supplemental seal to form a cement column in the casing-casing annulus via a second ported collar.

First claim

The invention claimed is:

1. A eutectic alloy system, comprising:
a sealing assembly including:
a differential valve tool within a casing-casing annulus defined in a wellbore between a first casing string and a second casing string extended within the wellbore, the differential valve tool being operable to establish a primary annular seal across the casing-casing annulus;
a first ported collar positioned above the differential valve tool in the wellbore and operable to establish fluid communication between an interior of the second casing string and the casing-casing annulus;
a eutectic alloy blanket positioned above the differential valve tool in the casing-casing annulus; and
a second ported collar positioned proximal to the eutectic alloy blanket in the wellbore and operable to establish fluid communication between the interior of the second casing string and the casing-casing annulus;

a source of a flushing fluid in selective fluid communication with the first ported collar through the interior of the second casing string;
a heater selectively operable to melt the eutectic alloy blanket and thereby permit the eutectic alloy blanket to form a secondary seal in the casing-casing annulus above the primary annular seal upon solidification; and
a source of cement in selective fluid communication with the second ported collar through the interior of the second casing string.

2. The eutectic alloy system of claim 1 , further comprising a tool string extendable within the interior of the second casing string, wherein the source of flushing fluid and the source of cement are in selective fluid communication with the first and second ported collars through the tool string.

3. The eutectic alloy system of claim 2 , wherein the tool string includes a plurality of pressure cups operable to engage the second casing string on opposed sides of the differential valve tool, the first ported collar, the second ported collar, or a combination thereof.

4. The eutectic alloy system of claim 3 , wherein the heater is positioned on the tool string and utilizes conductive or radiative heating to melt the eutectic alloy blanket through the second casing string.

5. The eutectic alloy system of claim 3 , wherein the heater is extendable within the interior of the second casing string via a heater line, and wherein the heater includes an electrical or chemical heating component.

6. The eutectic alloy system of claim 1 , further comprising:
a pump in fluid communication with the source of the flushing fluid and operable to pump the flushing fluid downhole; and
a fluid line operable to receive the flushing fluid from the pump,
wherein the fluid line is in fluid communication with the interior of the second casing string to supply the flushing fluid to the first ported collar.

7. The eutectic alloy system of claim 1 , wherein the eutectic alloy blanket includes a bismuth-based alloy.

8. The eutectic alloy system of claim 1 , wherein the differential valve tool includes a hydraulically or pneumatically activated packer to generate the primary annular seal.

9. The eutectic alloy system of claim 8 , wherein the hydraulically or pneumatically activated packer includes a rubber gasket, and wherein the eutectic alloy blanket includes a greater corrosion resistance than the rubber gasket.

10. A method, comprising:
running a eutectic alloy system into a wellbore including a first casing string and a second casing string arranged within the wellbore;
activating a differential valve tool within the second casing string and thereby generating a primary annular seal within a casing-casing annulus defined between the first and second casing strings;
pumping a flushing fluid into the casing-casing annulus above the primary annular seal via a first ported collar;
melting a eutectic alloy blanket into a molten alloy within the flushing fluid in the casing-casing annulus via a heater;
solidifying the molten alloy to establish a supplemental seal above the primary annular seal in the casing-casing annulus; and
pumping cement into the casing-casing annulus above the supplemental seal to form a cement column in the casing-casing annulus via a second ported collar.

11. The method of claim 10 , further comprising pumping, via a pump at a first external location, the flushing fluid from a reservoir to a fluid line in fluid communication with second casing string.

12. The method of claim 10 , further comprising pumping, via a cement pump at a second external location, the cement from a cement reservoir to a cement line in fluid communication with the second casing string.

13. The method of claim 10 , further comprising running a tool string including the heater thereon within the second casing string to locate the heater at or near the eutectic alloy blanket.

14. The method of claim 10 , further comprising:
running a tool string including a plurality of pressure cups thereon and seatable around the differential valve tool;
seating the plurality of pressure cups across the differential valve tool;
applying a hydraulic or pneumatic pressure to the differential valve tool between the pressure cups; and
actuating a packer within the differential valve tool to generate the primary annular seal.

15. The method of claim 14 , further comprising:
retracting the tool string to seat the plurality of pressure cups around the first ported collar;
applying a hydraulic or pneumatic pressure to the first ported collar; and
rupturing one or more rupture disks of the first ported collar to enable the flushing fluid to flow therethrough.

16. The method of claim 15 , further comprising:
retracting the tool string to seat the plurality of pressure cups around the second ported collar;
applying a hydraulic or pneumatic pressure to the second ported collar; and
rupturing one or more rupture disks of the second ported collar to enable the cement to flow therethrough.

17. A wellbore cement repair system, comprising:
a first casing string cemented into a wall at a first depth of a wellbore;
a second casing string run within the first casing string to form a casing-casing annulus and partially cemented at a further depth of the wellbore;
a differential valve tool within the casing-casing annulus and operable to establish a primary annular seal across the casing-casing annulus;
a first ported collar positioned above the differential valve tool in the wellbore and operable to establish fluid communication between an interior of the second casing string and the casing-casing annulus;
a eutectic alloy blanket positioned above the differential valve tool in the casing-casing annulus in the wellbore;
a second ported collar positioned proximal to the eutectic alloy blanket in the wellbore and operable establish fluid communication between the interior of the second casing string and the casing-casing annulus;
a source of a flushing fluid in selective fluid communication with the first ported collar through the interior of the second casing string;
a heater selectively operable to melt the eutectic alloy blanket and thereby permit the eutectic alloy blanket to form a secondary seal in the casing-casing annulus above the primary annular seal upon solidification; and
a source of cement in selective fluid communication with the second ported collar through the interior of the second casing string.

18. The wellbore repair system of claim 17 , further comprising a plurality of pressure cups within the second casing string and operable to seat around the differential valve tool, the first ported col

Assignees

• Saudi Arabian Oil Co

Inventors

• Alshaarawi Amjad
• Marhoon Zahrah
• Atiyah Abdullah
• Bukhamseen Ahmed
• Heinold Thomas
• Egbe Peter
• Gallelli Alessandro

Classifications

• E21B36/00

  Heating, cooling or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones · CPC title

• E21B33/16 Primary

  using plugs for isolating cement charge; Plugs therefor {(stage cementing E21B33/146; spacer compositions C09K8/424)} · CPC title