Shear activated inflation fluid system for inflatable packers
View Patent ↗A subterranean well packer is inflated by a pumped transfer of rheotropic fluid through a tortuous flow channel into a packer sealing element expansion chamber. The tortuous flow channel and fluid delivery pressure are coordinated with the fluid properties to impose sufficient fluid shear stress for inducement of a substantial phase change in said rheotropic fluid after entry into expansion chamber.
1. A subterranean well packer comprising:
(a) a tubular mandrel formed about a fluid flow bore;
(b) a resilient well sealing element formed about said mandrel and secured thereto at opposite axial ends whereby said element may be expanded to form a fluid seal with a well wall;
(c) an expansion chamber between said sealing element and said mandrel;
(d) a fluid flow channel between said fluid flow bore and said expansion chamber; and,
(e) a fluid flow labyrinth in said fluid flow channel for activating a rheotropic fluid.
2. A well packer as described by claim 1 wherein said fluid flow channel comprises a one-way fluid flow check valve.
3. A well packer as described by claim 2 wherein said labyrinth is positioned in said flow channel between said check valve and said expansion chamber.
4. A well packer as described by claim 1 wherein the fluid flow labyrinth comprises a chamber having a series of baffles disposed therewithin in a substantially parallel relation to define a plurality of fluid flow spaces within the chamber.
5. A well packer as described by claim 4 wherein each of the baffles contains a fluid flow aperture, each of the fluid flow apertures being misaligned with fluid flow apertures in neighboring baffles so as to create a tortuous flow path through the chamber.
6. A well packer as described by claim 2 wherein said check valve comprises a ball-shaped valve member that is biased against a valve closure seat.
7. A well packer comprising:
(a) a tubular mandrel formed about a fluid flow bore;
(b) a resilient well sealing element formed about said mandrel and secured thereto at opposite axial ends whereby said element may be expanded to form a fluid seal with a well wall;
(c) an expansion chamber between said sealing element and said mandrel; and,
(d) a labyrinthine fluid flow path for ingress of fluid into the expansion chamber, the fluid flow path being sufficiently labyrinthine to activate a rheotropic fluid.
8. A well packer as described by claim 7 further comprising a one-way fluid flow check valve.
9. A well packer as described by claim 7 wherein the fluid flow labyrinth comprises a chamber having a series of baffles disposed therewithin in a substantially parallel relation to define a plurality of fluid flow spaces within the chamber.
10. A well packer as described by claim 9 wherein each of the baffles contains a fluid flow aperture, each of the fluid flow apertures being misaligned with fluid flow apertures in neighboring baffles so as to create a tortuous flow path through the chamber.
11. A well packer as described by claim 8 wherein said check valve comprises a ball-shaped valve member that is biased against a valve closure seat.
12. A method of setting a subterranean well packer comprising the steps of:
providing a tortuous flow path for a packer inflation fluid proximate of a packer element inflation chamber; and,
inflating said packer element with a rheotropic fluid delivered along said tortuous flow path into said inflation chamber.
13. A method as described by claim 12 wherein flow of said rheotropic fluid along said flow path is restricted to one-way flow.
14. A method as described by claim 12 wherein the tortuous flow path is provided by a series of baffles disposed therewithin in a substantially parallel relation to define a plurality of fluid flow spaces therebetween within the chamber.
15. The method of claim 13 wherein the flow of said rheotropic fluid is restricted to one way flow by a check valve.