Packing element back-up system incorporating iris mechanism

Patent metadata

Field	Value
Publication number	US-10487614-B2
Application number	US-201515568255-A
Country	US
Kind code	B2
Filing date	May 29, 2015
Priority date	May 29, 2015
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

An annular sealing assembly and method are disclosed. The assembly includes a mandrel and an expandable element disposed around the mandrel which expands to seal against the inner diameter of a tubing or casing string. The expandable element seals the mandrel from the annulus between the mandrel and the tubing string. The assembly includes at least one back¬up element having a plurality of pivoting blades circumferentially secured in a ring around the mandrel. The back-up element is capable of radially expanding and contracting upon longitudinal movement along, and engagement with, a generally ring-shaped ramp. A guide ring guides the back-up element along the guide ramp. The method is directed to expanding the expandable element to seal the annulus and the back-up element so the blades come in contact with the inner diameter of the tubing string preventing the expandable element from extruding outward into the annulus beyond the back-up element.

First claim

What is claimed is:

1. An annular sealing assembly, comprising:
a mandrel;
an expandable element disposed around the mandrel having a generally tubular shape and oppositely disposed longitudinal ends;
a generally ring-shaped guide ramp disposed around the mandrel adjacent one of the oppositely disposed longitudinal opposite ends of the expandable element;
a back-up element having a plurality of pivoting blades circumferentially secured in a ring, the back-up element being disposed around the mandrel adjacent the generally ring-shaped guide ramp and being capable of radially expanding and contracting upon longitudinal sliding movement along a longitudinally tapered surface of, and engagement with, the generally ring-shaped guide ramp;
a guide ring disposed around the mandrel adjacent the back-up element, the guide ring being capable of guiding the back-up element longitudinally along the generally ring-shaped guide ramp and providing structural support to a base of the expandable back-up element; and
wherein the ring-shaped guide ramps comprise a first ring having a flat surface oriented in an axial direction, a second ring having a flat surface oriented in a radial direction, the flat surface of the first ring being formed perpendicular to the flat surface of the second ring, and a plurality of ramps formed between the first and second rings.

2. The annular sealing assembly according to claim 1 , further comprising:
a second ring-shaped guide ramp disposed around the mandrel adjacent the other longitudinal end of the expandable element;
a second back-up element having a plurality of pivoting blades circumferentially secured in a ring, the second back-up element being disposed around the mandrel adjacent the second ring-shaped guide ramp and being capable of radially expanding and contracting upon longitudinal sliding movement along a longitudinally tapered surface of the second ring-shaped guide ramp; and
a second guide ring disposed around the mandrel adjacent the second back-up element, the second guide ring being capable of guiding the second back-up element longitudinally along the second ring-shaped guide ramp.

3. The annular sealing assembly according to claim 2 , wherein the mandrel is a section of production string.

4. The annular sealing assembly according to claim 3 , wherein each of the ramps projects radially outward from the first ring and tapers radially and axially to the second ring.

5. The annular sealing assembly according to claim 4 , wherein a flat surface is formed between adjacent ramps.

6. The annular sealing assembly according to claim 2 , wherein the expandable element comprises a material selected from the group consisting of an elastomer, a rubber, a fluid filled bag, metallic elements, and combinations thereof.

7. The annular sealing assembly according to claim 2 , wherein the plurality of pivoting blades in each of the back-up elements have an outer diameter (OD) which is less than an outer diameter (OD) of the expandable element and an inner diameter (ID) which conforms to an outer diameter (OD) of the mandrel when the pivoting blades are in the retracted position.

8. The annular sealing assembly according to claim 7 , wherein the plurality of pivoting blades in each of the back-up elements are formed of two sets of blades which are connected to and pivot relative to each other in a circumferential direction with respect to an axis of the ring-shaped guide ramp, and the blades in the first set alternate in their placement around the circumference of the back-up elements with the blades in the second set and wherein blades in the first set are offset circumferentially from the blades in the second set.

9. The annular sealing assembly according to claim 8 , wherein the blades of the first set are connected to and pivot relative the blades of the second set in at least one location.

10. The annular sealing assembly according to claim 9 , wherein one of the two guide rings is fixed to the mandrel and the other of the two guide rings is allowed to move axially along the mandrel.

11. The annular sealing assembly according to claim 9 , wherein both of the guide rings are allowed to move axially along the mandrel.

12. The annular sealing assembly according to claim 2 , wherein the plurality of pivoting blades in each of the back-up elements have an outer diameter (OD) which conforms to an inner diameter (ID) of a section of tubing string into which the annular sealing assembly may be placed when the pivoting places are in the expanded position.

13. The annular sealing system according to claim 1 , wherein each pivoting blade of the plurality of pivoting blades comprises an arcuate-shaped inner surface extending circumferentially about an axis of the ring-shaped guide ramp, wherein a totality of the arcuate-shaped inner surface of each pivoting blade is in contact with the ring-shaped guide ramp when the back-up element is in a contracted position.

14. A method of sealing an annulus between a mandrel and a tubing string, comprising:
expanding an expandable element disposed around the mandrel until it contacts an inner diameter of the tubing string, wherein the expandable element is disposed around the mandrel and has a tubular shape and oppositely disposed longitudinal ends;
wherein a ring-shaped guide ramp is disposed around the mandrel adjacent one of the oppositely disposed longitudinal ends of the expandable element;
expanding a back-up element disposed adjacent to the expandable element from a retracted position to an expanded position, the back-up element having a plurality of pivoting blades circumferentially secured in a ring, and the back-up element being disposed around the mandrel adjacent the ring-shaped guide ramp and being capable of radially expanding and contracting upon longitudinal sliding movement along a longitudinally tapered surface of the ring-shaped guide ramp, the blades in the expanded position coming in contact with the inner diameter of the tubing string and preventing the expandable element from extruding outward into the annulus beyond the back-up element;
wherein a guide ring is disposed around the mandrel adjacent the back-up element, the guide ring being capable of guiding the back-up element longitudinally along the ring-shaped guide ramp and providing structural support to a base of the back-up element; and
wherein the ring-shaped guide ramps comprise a first ring having a flat surface oriented in an axial direction, a second ring having a flat surface oriented in a radial direction, the flat surface of the first ring being formed perpendicular to the flat surface of the second ring, and a plurality of ramps formed between the first and second rings.

15. The method according to claim 14 , further comprising expanding a second back-up element disposed adjacent to the expandable element on the side opposite the other back-up element from a retracted position to an expanded position, the second back-up element having a plurality of pivoting blades circumferentially secured in a ring, the blades in the expanded position coming in contact with the inner diameter of the tubing string and preventing the expandable element from extruding outward into the annulus beyond the second back-up element.

16. The method according to claim 15 , wherein the back-up elements are moved around the guide ramps by a pair of guide rings including the guide ring disposed adjacent to the respective back-up elements.

17. The method according to claim 16 , wherein at least one of the guide rings moves axially along the mandrel.

1

Assignees

• Halliburton Energy Services Inc

Inventors

• Macdonald Lorn Scott

Classifications

• E21B34/06

  in wells · CPC title

• E21B33/128

  with a member expanded radially by axial pressure (E21B33/122, E21B33/124 take precedence) · CPC title

• E21B33/12 Primary

  Packers; Plugs (used for cementing E21B33/134, E21B33/16) · CPC title

• E21B33/1216 Primary

  Anti-extrusion means, e.g. means to prevent cold flow of rubber packing · CPC title