Sealing system

Patent metadata

Field	Value
Publication number	US-9447651-B2
Application number	US-201113819478-A
Country	US
Kind code	B2
Filing date	Aug 30, 2011
Priority date	Aug 31, 2010
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

The present invention relates to sealing method for sealing a zone of a casing in a well, the zone comprising several leaks, perforations and/or weakened casing parts, or other irregularities having a casing characteristic which, when measured, is found to be outside a predetermined interval. The sealing method comprises the steps of measuring the characteristics of the casing, determining a position of the zone, determining an extent of the zone in a longitudinal direction of the casing, determining a part of the zone and an extent of the part whose casing characteristic when measured is within the predetermined interval, the part extending in the longitudinal direction of the casing, positioning a first liner overlapping the first area of the part of the casing, positioning a second liner overlapping the second area of the part of the casing, expanding the first liner, and expanding the second liner.

First claim

The invention claimed is:

1. A sealing method for sealing an imperfect zone of a casing in a well, comprising:
measuring a characteristic of the casing, the characteristic being related to structural damage or weakening of the casing at a particular location;
evaluating the characteristic and classifying the characteristic as acceptable or imperfect along a plurality of locations in a longitudinal section of the casing relative to a predetermined value;
locating a first damaged or weakened zone randomly located in the casing, the first damaged or weakened zone comprising two discrete damaged or weakened sections of the casing, the first damaged or weakened section of the casing being separated longitudinally from the second damaged or weakened section of the casing by an acceptable region;
positioning a first liner overlapping the first damaged or weakened section and a first portion of the acceptable region;
positioning a second liner overlapping the second damaged or weakened section and a second portion of the acceptable region different from the first portion;
ensuring a third portion of the acceptable region exists between the first portion and second portion and dimensioning the third portion to have a minimum predetermined extent based on the locating of the first and second damaged or weakened zones such that no liner overlaps the third portion;
expanding the first liner; and
expanding the second liner.

2. The sealing method according to claim 1 , wherein the measuring is performed by means of acoustics.

3. The sealing method according to claim 1 , wherein the positioning is performed by means of a casing collar locator, a positioning tool using magnetism, or a distance measuring device.

4. The sealing method according to claim 1 , wherein the expanding is performed by means of an expansion device.

5. The sealing method according to claim 1 , wherein the method comprises determining a second damaged or weakened zone as well as a second acceptable region and a third damaged or weakened section within the second damaged or weakened zone, the second acceptable region being arranged longitudinally adjacent to the first damaged or weakened zone.

6. The sealing method according to claim 1 , wherein:
the measuring step comprises a logging unit for measuring the characteristics of a casing downhole,
the evaluating step comprises a control unit for evaluating the characteristic and locating a position along the casing in which the characteristic has been measured, and
the positioning step comprises a liner setting unit comprising the first liner and the second liner.

7. The sealing method according to claim 6 , wherein the liner setting unit comprises a body and at least one expansion device for expanding the liners.

8. The sealing method according to claim 6 , wherein the liner setting unit comprises at least two liner setting tools, each liner setting tool comprising a liner, a body, an expansion device and a shaft for connecting the expansion device with the body.

9. The sealing method according to claim 6 , wherein the liner setting unit comprises the two liners, a body, an expansion device and a shaft for connecting the expansion device with the body.

10. The sealing method according to claim 9 , wherein the liner setting unit comprises the two liners arranged between two bodies and two expansion devices arranged between the two liners each moving towards one of the bodies for expanding one of the liners, the liner setting unit comprising a shaft for connecting the expansion devices with the bodies.

11. The sealing method according to claim 6 , further comprising a positioning tool.

12. The sealing method according to claim 6 , further comprising moving the downhole system in the casing with a driving unit.

13. The sealing method according to claim 6 , wherein the liner setting unit comprises an expandable device and a liner.

14. The sealing method according to claim 2 , wherein the acoustics include ultrasound, vibration, sound or infrasound, capacitance, magnetism, X-ray, infrared light, visible light, laser, UV light, or microwaves.

15. The sealing method of claim 1 , wherein the structural damage or weakening is a result of an unexpected perforation in the casing or a decrease in a thickness of the casing relative to a previously measured portion of the casing.

16. The sealing method according to claim 1 , wherein the damaged or weakened zone is a result of unexpected leaks, perforations, and/or weakened locations in the casing.

Assignees

• Hallundbaek Jorgen
• Welltec As

Inventors

• Hallundbaek Jorgen

Classifications

• E21B29/10 Primary

  Reconditioning of well casings, e.g. straightening · CPC title

• E21B43/103

  of expandable casings, screens, liners, or the like · CPC title

• E21B43/10

  Setting of casings, screens, liners {or the like} in wells · CPC title