Isolation tool and methods of isolating a section of pipe or a vessel

1. An isolation tool for isolating a section of a pipe or a vessel,

the isolation tool comprising:

a head unit configured for location in a section of a pipe or a vessel, the head unit comprising:

at least one groove around a circumference of the head unit, each of the at least one grooves comprising a first end within the head unit, a second end open to the exterior of the head unit, and a curvature therebetween; and

a circumferential seal element disposed within each of the at least one grooves and spanning at least a portion of the curvature;

wherein the circumferential seal element is configured within the groove such that a force at or near the first end of the groove imparts radial expansion of the circumferential seal element at the second end of the groove via the curvature in the groove, and

wherein each of the at least one grooves is a fixed structure that remains the same shape and size during application of the force that imparts the radial expansion of the circumferential seal element.

2. The isolation tool of claim 1 , wherein the curvature of the at least one groove is a bend forming an angle between about 60 degrees and about 120 degrees.

3. The isolation tool of claim 1 , wherein the curvature of the at least one groove is a bend forming a 90 degree corner.

4. The isolation tool of claim 1 , wherein the at least one groove narrows at the second end.

5. The isolation tool of claim 1 , wherein each of the at least one grooves further comprises two or more groove channels, each of the two or more groove channels extending at least-a portion of the first end of the groove further within the head unit, and each of the two or more groove channels spaced apart from each other around the circumference.

6. The isolation tool of claim 5 , wherein each of the two or more groove channels are spaced equidistant around the circumference.

7. The isolation tool of claim 5 , wherein a portion of the circumferential seal element extends within the two or more groove channels.

8. The isolation tool of claim 1 , wherein the circumferential seal element comprises a seal portion for engaging the pipe or the vessel upon activation and a seal engagement portion for receiving the force, the seal engagement portion located proximal to the first end of the at least one groove relative to the seal portion.

9. The isolation tool of claim 8 , wherein the seal portion is comprised of natural rubber, synthetic rubber, urethane, or polyurethane, and the seal engagement portion is comprised of a material of different hardness than the seal portion.

10. The isolation tool of claim 8 , wherein the seal engagement portion and seal portion of the circumferential seal element are dimensioned to contact each other within the first end or the curvature of the at least one groove to impart radial expansion of the seal portion.

11. The isolation tool of claim 8 , wherein the seal engagement portion and the seal portion are separate units positioned adjacent to each other to form the circumferential seal element.

12. The isolation tool of claim 8 , wherein the seal engagement portion and seal portion of the circumferential seal element are dimensioned to contain a medium therebetween, wherein the force acting upon the seal engagement portion is transferred to the seal portion via the medium to impart radial expansion of the seal portion.

13. The isolation tool of claim 12 , wherein the medium is a fluid.

14. The isolation tool of claim 1 , wherein the at least one groove is two grooves.

15. The isolation tool of claim 14 , which comprises a bleed port open to the exterior of the head unit between the two grooves, the bleed port in fluid communication with a bleed conduit within the head unit.

16. The isolation tool of claim 14 , wherein the isolation tool is configured such that the radial expansion of the circumferential seal element of each of the two grooves can be independently activated.

17. The isolation tool of claim 1 , further comprising a carrier unit having a pivotal connection to the head unit, wherein the carrier unit is pivotally connected to an arm assembly that is connected to the head unit.

18. The isolation tool of claim 1 , wherein the force is a fluid force.

19. The isolation tool of claim 18 , wherein the head unit comprises a fluid conduit in fluid communication with the first end of the at least one groove and configured for providing the fluid force to impart radial expansion of the circumferential seal element at the second end.

20. The isolation tool of claim 19 , wherein the head unit comprises a core having a fluid channel, the fluid channel forming at least a portion of the fluid conduit.

21. The isolation tool of claim 20 , wherein the head unit comprises an internal member defining a bore to receive the core, the internal member defining a lower wall of the groove.

22. The isolation tool of claim 19 , wherein the head unit comprises a piston disposed within the at least one groove between the fluid conduit and the circumferential seal element.

23. The isolation tool of claim 22 , wherein the piston is a circumferential ring comprised of a metal or a metallic alloy.

24. The isolation tool of claim 22 , wherein the head unit comprises a locking mechanism for releasably locking the piston in an activated position.

25. The isolation tool of claim 24 , wherein radial expansion of the circumferential seal element is reversible upon release of the locking mechanism.

26. The isolation tool of claim 1 , wherein the force is a mechanical force, and wherein the head unit comprises a piston disposed within the groove to provide the mechanical force.

27. The isolation tool of claim 1 , wherein the force is a mechanical force, and wherein the head unit comprises a threaded ring disposed within the at least one groove, wherein the threaded ring travels on threads in the groove to shift the circumferential seal element between an activated and deactivated state.

28. The isolation tool of claim 1 , wherein the curvature of the at least one groove is a bend having an inner radius of curvature of between about 0.2 inches and about 0.5 inches; and an outer radius of curvature of between about 1.0 inches and 1.5 inches.

29. The isolation tool of claim 1 , wherein the at least one groove has a uniform width from the first end to the second end.

30. The isolation tool of claim 29 , wherein the uniform width is between 0.5 inches and 1.0 inch.