Isolation plug with energized seal
A pipeline isolation tool [ 10 ] and method of its use includes a plugging head [ 20 ] having a seal [ 30 ] to sealably engage a pipe wall; a fluid-activated cylinder [ 64 ] located on one side of the seal and moveable in an axial direction; metal support segments [ 40 ] located on another side of the seal and moveable in a transverse direction radially outward and inward; the metal segments including a concave portion [ 45 ], a portion [ 35 ] of the seal residing within the concave portion when unset and set. When in a seal unset position a portion [ 33 ] of the seal is covered by adjacent metal support segments of the plurality. When in a seal set position the portion of the seal is exposed between the adjacent metal support segments. The seal is self-energizing, its actuating force being in a same direction as a force from isolation pressure.
1. A pipeline isolation tool [ 10 ] comprising:
at least one plugging head [ 20 ] including a seal [ 30 ] expandable between an unset and a set position;
a plurality of metal support segments [ 40 ] located on a side of the seal and moveable in a transverse direction radially outward and inward as the seal moves between the unset and set positions;
each metal support segment of the plurality including a seal-facing surface [ 41 ] including at least two inclined thrust surfaces [ 43 A, 43 B, 43 C] and a concave-portion [ 45 ] containing one of the at least two inclined thrust surfaces, a portion [ 35 ] of the side of the seal residing within the concave portion when in the unset and set positions;
wherein in the unset position a portion [ 33 ] of the seal is covered by adjacent metal support segments of the plurality; and
wherein in the set position the portion of the seal is exposed between the adjacent metal support segments.
2. The pipeline isolation tool of claim 1 , further comprising:
the at least one plugging head including a sweep [ 50 ] having a curved lower end [ 51 ].
3. The pipeline isolation tool of claim 2 , further comprising:
the curved lowered end of the sweep being located below the at least one plugging head when the seal is in an unset position and forward of the at least one plugging head when the seal is in the set position.
4. The pipeline isolation tool of claim 2 , further comprising:
the sweep including a plurality of ribs [ 53 ].
5. The pipeline isolation tool of claim 1 , further comprising:
a hinge [ 23 ] containing a transfer pin [ 70 ] including a plurality of fluid passageways [ 71 , 73 ], the at least one plugging head being in pivotal relation to the hinge.
6. The pipeline isolation tool of claim 5 , further comprising:
at least one fluid passageway of the plurality of fluid passageways being a hydraulic fluid passageway; and
at least one other fluid passageway of the plurality of fluid passageways being a gas or liquid passageway.
7. The pipeline isolation tool of claim 1 , further comprising:
the seal including
an outer pipe wall facing portion [ 39 ] having a first shore hardness; and
another portion [ 38 ] inward of the outer pipe wall facing portion having a second shore hardness greater than the first shore hardness.
8. The pipeline isolation tool of claim 1 , further comprising:
a control bar head [ 80 ] connected to the at least one plugging head, the control bar head including a pair of spaced-apart feet [ 81 ] located at a lower end [ 83 ] of the control bar head, one foot of the pair lying left of a vertical centerline [ 89 ] of the control bar head and another foot of the pair lying right of the vertical centerline.
9. The pipeline isolation tool of claim 8 , further comprising:
the control bar head including a stop [ 87 ] configured to orient the at least one plugging head in a first orientation during run-in to an interior of a pipe and at second different orientation when in the pipe.
10. The pipeline isolation tool of claim 8 , further comprising a second plugging head [ 20 B] in pivotal relation to the at least one plugging head.
11. The pipeline isolation tool of claim 1 , further comprising a fluid-activated cylinder [ 64 ] located on an opposite side of the seal, the fluid-activated cylinder moveable in an axial direction toward the seal.
12. The pipeline isolation tool of claim 11 , further comprising the fluid-activated cylinder including a seal-facing surface [ 61 ] oriented at an incline to the opposite side of the seal.
13. The pipeline isolation tool of claim 12 , wherein the seal-facing surface of the fluid-activated cylinder [ 64 ] is planar along its entire length.
14. The pipeline isolation tool of claim 12 , the seal-facing surface of the metal segment includes a lower portion [ 47 ] that runs parallel to the seal-facing surface of the fluid-activated cylinder and an upper portion [ 44 ] that runs non-parallel to the seal-facing surface of the fluid-activated cylinder.
15. The pipeline isolation tool of claim 1 , wherein a horizontal length of a bottom end [ 48 ] of the concave portion is proportional to a horizontal spacing between the seal-facing surface of the metal segment and the seal-facing surface of the fluid-activated cylinder.
16. The pipeline isolation tool of claim 1 , further comprising the seal-facing surface of the metal segment including a top and a bottom end [ 44 , 47 ] and at least two portions [ 43 , 45 ] that do not extend an entire distance between the top and bottom ends and run at different angles than one another relative to vertical.
17. The pipeline isolation tool of claim 1 , wherein the at least two inclined thrust surfaces have different inclines.
18. The pipeline isolation tool of claim 1 , the one of the at least two inclined thrust surfaces forms an upper end [ 49 ] of the concave portion.
19. The pipeline isolation tool of claim 1 , wherein another one of the at least two inclined thrust surfaces is located on a lower half [ 42 ] of the seal-facing surface.
20. The pipeline isolation tool of claim 1 , wherein a vertical height of the concave portion is proportional to an overall vertical height of the seal-facing surface 41 of the metal segment.
21. The pipeline isolation tool of claim 1 , wherein the concave portion is a quadrilateral-shaped cavity.
22. A plugging head [ 20 ] adapted for use in pipeline isolation, the plugging head comprising:
a seal [ 30 ] sized to engage a pipe wall and having an unset position and a set position;
a plurality of metal support segments [ 40 ] located on a side of the seal and moveable between the unset and set positions in a transverse direction radially outward and inward;
each metal support segment of the plurality including a seal-facing surface [ 41 ] including at least two inclined thrust surfaces [ 43 A, 43 B, 43 C] and a concave-portion [ 45 ] containing one of the at least two inclined thrust surfaces, a portion [ 35 ] of the side of the seal residing within the concave portion when in the unset and set positions;
wherein in the unset position a portion [ 33 ] of the seal is covered by adjacent metal support segments of the plurality; and
wherein in the set position the portion of the seal is exposed between the adjacent metal support segments.
23. The plugging head of claim 22 , wherein in the unset position, each metal support and the seal, together, have a substantially trapezoidal, but not parallelogrammatic, cross-section.
24. The plugging head of claim 22 , further comprising a third inclined thrust service, the third inclined thrust surface and another one of the at least two inclined thrust surfaces located below the concave portion.