INFLATABLE SLEEVE WITH CONTROLLED EXPANSION

• US 20160208572A1
• Filed: 08/20/2014
• Published: 07/21/2016
• Est. Priority Date: 08/20/2013
• Status: Active Grant

• Current Assignee: Calyf
• Original Assignee: Calyf
• Inventors: Cour, Francis
• Granted Patent: US 10,443,341 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E21B 33/127 with inflatable sleeve E21B33/122, E21B33/124 take precedence
• CPC Class Codes: E21B 33/1277 characterised by the construction or fixation of the sleeve

Abstract

The inflatable sleeve (13) comprises:

• • a mandrel (15) extending in a longitudinal direction;
  • an inflatable casing (17) placed around the mandrel (15);
  • a tubular sheath (19) slid around the casing (17), the tubular sheath (19) having a central segment (27) and first and second longitudinal ends (23, 25) situated on either side of the central segment (27), the first and/or second ends (23, 25) of the tubular sheath (19) being fixed to the mandrel (15), the tubular sheath (19) being extensible from a rest state to an expanded state.

The tubular sheath (19) has a predetermined circumferential elongation capacity from the rest state of the tubular sheath (19); and

• • the first and/or second ends (23, 25) of the tubular sheath (19) have a longitudinal elongation capacity from the rest state of the tubular sheath (19) comprised between 1.05 and 2.5, chosen to limit the diametric expansion of the first and/or second ends (23, 25) of the tubular sheath and give the first and/or second ends their shape (23, 25).

Claims

1. An inflatable sleeve, the sleeve comprising:

a mandrel extending in a longitudinal direction;

an inflatable casing placed around the mandrel;

a tubular sheath slid around the casing, the tubular sheath having a central segment and first and second longitudinal ends situated on either side of the central segment, the first and/or second ends of the tubular sheath being fixed to the mandrel, the tubular sheath being extensible from a rest state to an expanded state;

wherein

the tubular sheath has a predetermined circumferential elongation capacity from the rest state of the tubular sheath; and

the first and/or second ends of the tubular sheath have a longitudinal elongation capacity from the rest state of the tubular sheath comprised between 1.05 and 2.5, chosen to limit the diametric expansion of the first and/or second ends of the tubular sheath and give the first and/or second ends their shape.

2. The sleeve according to claim 1, wherein the central segment of the tubular sheath has said predetermined circumferential elongation capacity, and the first and/or second ends of the tubular sheath have a circumferential elongation capacity from the rest state of the tubular sheath close to said predetermined circumferential elongation capacity of the central segment.

3. The sleeve according to claim 1, wherein the central segment and the first and second ends of the tubular sheath have substantially equal respective circumferential elongation capacities from the rest state of the tubular sheath.

4. The sleeve according to claim 1, wherein the tubular sheath comprises longitudinal yarns and at least one circumferential yarn,

the circumferential yarn having a predetermined ultimate strength from the rest state of the tubular sheath;

and

the longitudinal yarns having an ultimate strength from the rest state of the tubular sheath comprised between 1.05 and 2.5 to limit the diametric expansion of the first end of the tubular sheath and give it its shape.

5. The sleeve according to claim 4, wherein the circumferential yarn is interlaced with the longitudinal yarns.

6. The sleeve according to claim 4, wherein the circumferential yarn belongs to a first ply, the longitudinal yarns belonging to a second ply separate from the first ply.

7. The sleeve according to claim 4, wherein each circumferential and/or longitudinal yarn is substantially inextensible, at least one segment of the circumferential and/or longitudinal yarn adopting a folded configuration in the rest state of the tubular sheath and a stretched configuration in the expanded state of the tubular sheath.

8. The sleeve according to claim 4, wherein each longitudinal yarn has a maximum elongation rate from the rest state of the sheath substantially equal to π

/2.

9. The sleeve according to claim 4, wherein each circumferential and/or longitudinal yarn is inextensible once the maximum elongation rate is reached.

10. The sleeve according to claim 1, wherein the tubular sheath is fixed to the mandrel by a plurality of circumferences distributed longitudinally between the first and second longitudinal ends.

11. The sleeve according to claim 1, wherein the circumferential elongation capacity from the rest state of the tubular sheath is substantially constant along the entire tubular sheath.

12. A method for closing off a borehole successively crossing through first and second layers of terrain superimposed on one being relatively harder and less deformable, comprising positioning the sleeve according to claim 1 at an interface between the first and second layers.