Expandable metal sleeves in high-risk sections of fluid lines

1. A patch for a fluid line, comprising:

a tubular; and

a sleeve of expandable metal positioned about the tubular, the sleeve of expandable metal comprising a metal configured to expand in response to hydrolysis and thereby seal a leaking section of a fluid line, wherein the sleeve of expandable metal includes a first portion of expanded metal surrounding the leaking section, and a second portion of non-expanded metal radially inside of the first portion of expanded metal.

2. The patch as recited in claim 1 , wherein the tubular is a metal tubular.

3. The patch as recited in claim 1 , wherein the tubular is a concrete tubular.

4. The patch as recited in claim 1 , wherein the tubular is a polymeric tubular.

5. The patch as recited in claim 1 , wherein the tubular has a sidewall thickness (t t ) and the sleeve of expandable metal has a sidewall thickness (t s ), and further wherein the sidewall thickness (t s ) is less than the sidewall thickness (t t ).

6. The patch as recited in claim 5 , wherein the sidewall thickness (t s ) is at least 50% less than the sidewall thickness (t t ).

7. The patch as recited in claim 1 , wherein a first volume of the first portion of expanded metal is less than a second volume of the second portion of non-expanded metal.

8. The patch as recited in claim 7 , wherein the first volume of the first portion of expanded metal is no more than 50% of the second volume of the second portion of non-expanded metal.

9. The patch as recited in claim 1 , further including a delay coating surrounding the sleeve of expandable metal, the delay coating configured to protect those surfaces of the sleeve of expandable metal not in contact with the tubular from encountering a reactive fluid.

10. The patch as recited in claim 1 , wherein the sleeve of expandable metal is a collection of individual separate chunks of expandable metal held together with a binding agent.

11. A system, comprising:

a fluid line positioned within a surrounding medium; and

a patch positioned within the fluid line, the patch including;

a tubular; and

a sleeve of expanded metal positioned about the tubular, the sleeve of expanded metal comprising a metal that has expanded in response to hydrolysis to thereby seal a leaking section of the fluid line, wherein the sleeve of expandable metal includes a first portion of expanded metal surrounding the leaking section, and a second portion of non-expanded metal radially inside of the first portion of expanded metal.

12. The system as recited in claim 11 , wherein the surrounding medium is ground.

13. The system as recited in claim 12 , wherein the patch is located less than 150 meters below a surface of the ground.

14. The system as recited in claim 12 , wherein the patch is located less than 30 meters below a surface of the ground.

15. The system as recited in claim 11 , wherein the surrounding medium is water.

16. The system as recited in claim 11 , wherein the surrounding medium is air.

17. The system as recited in claim 11 , wherein the fluid line includes a first tubular section and a second tubular section forming a junction therebetween, and further wherein the sleeve of expandable metal surrounds the junction.

18. The system as recited in claim 17 , wherein the first tubular section and the second tubular section are within 10 degrees of parallel with one another, thereby forming a linear junction.

19. The system as recited in claim 18 , wherein the first tubular section and the second tubular section are greater than 20 degrees of parallel with one another, thereby forming a T-shaped junction or a Y-shaped junction.

20. A method for sealing a fluid line, comprising:

providing a fluid line within a surrounding medium; and

positioning a patch within the fluid line, the patch including;

a tubular; and

a sleeve of expandable metal positioned about the tubular, the sleeve of expandable metal comprising a metal configured to expand in response to hydrolysis, wherein the sleeve of expandable metal includes a first portion of expanded metal surrounding the leaking section, and a second portion of non-expanded metal radially inside of the first portion of expanded metal; and

allowing reactive fluid passing through the fluid line to react with the first portion of expanded metal and expand to form an expanded metal portion that seals a section of the tubular.

21. The method as recited in claim 20 , further including detecting a leak in the leaking section of the tubular.

22. The method as recited in claim 21 , wherein the detecting occurs prior to the positioning the patch within the fluid line.

23. The method as recited in claim 20 , wherein the surrounding medium is ground.

24. The method as recited in claim 20 , wherein the surrounding medium is water.