Downhole packer assembly

Abstract

A downhole packer assembly for expanding a metal patch in a well's downhole tubular metal structure has a body part with a longitudinal extension and a central part, a first expandable tubular element surrounding the body part and connected to the body part on one side, a second expandable tubular element surrounding the body part connected to the body part on an opposite side, and a metal patch having a first end, a second end, an inner face, and an outer face configured to face and abut the tubular metal structure. The metal patch surrounds the first and second tubular elements. The first tubular element is arranged at a first distance from the second tubular element in the longitudinal extension in a first operational state and at a second distance from the second tubular element in a second operational state, with the second distance being larger than the first.

What is claimed is: 
     
         1 . A downhole packer assembly for expanding a metal patch in a well downhole in a well tubular metal structure, comprising:
 a body part having a longitudinal extension and a central part;   a first expandable tubular element surrounding the body part and connected to the body part on one side of the central part,   wherein the first expandable tubular element has a first outer face;   a second expandable tubular element surrounding the body part and connected to the body part on an opposite side of the central part,   wherein the second expandable tubular element has a second outer face; and   a metal patch having a first end, a second end, an inner face, and an outer face configured to face and abut the well tubular metal structure,   wherein the metal patch has a first predefined length,   wherein the metal patch surrounds the first expandable tubular element and the second expandable tubular element,   wherein the first expandable tubular element is arranged at a first distance from the second expandable tubular element in the longitudinal extension in a first operational state,   wherein the first expandable tubular element is arranged at a second distance from the second expandable tubular element in the longitudinal extension in a second operational state, and   wherein the second distance is longer than the first distance.   
     
     
         2 . The downhole packer assembly according to  claim 1 ,
 wherein the body part comprises a first tubular part having a first end and a second end, and a second tubular part having a first end and a second end,   wherein the second end of the first tubular part is arranged at a first distance from the first end of the second tubular part in the first operational state, and   wherein the second end of the first tubular part is arranged at a second distance from the first end of the second tubular part in the second operational state.   
     
     
         3 . The downhole packer assembly according to  claim 1 , wherein the position of the first expandable tubular element is secured at the first distance relative to the second expandable tubular element in the first operational state, and when an expansion fluid reaches a predefined pressure threshold, the expansion fluid imposes a force on the first expandable tubular element and/or the second expandable tubular element to release the first expandable tubular element and/or the second expandable tubular element relative to the second tubular element. 
     
     
         4 . The downhole packer assembly according to  claim 1 , wherein, in the first operational state, the outer face of the first expandable tubular element and the outer face of the second expandable tubular element are in contact with the inner face of the metal patch, defining a center volume. 
     
     
         5 . The downhole packer assembly according to  claim 1 , wherein the body part has a first fluid outlet in fluid communication with an expandable space of the first expandable tubular element and a second fluid outlet in fluid communication with an expandable space of the second expandable tubular element. 
     
     
         6 . The downhole packer assembly according to  claim 1 , wherein the body part has a third fluid outlet in fluid communication with a confined space defined by the first expandable tubular element, the second expandable tubular element, and an inner face of the metal patch. 
     
     
         7 . The downhole packer assembly according to  claim 6 , wherein the third fluid outlet is positioned in the central part. 
     
     
         8 . The downhole packer assembly according to  claim 6 ,
 wherein the third fluid outlet comprises a first pressure reduction valve having a first fluid pressure input and a first fluid pressure output,   wherein the first fluid pressure output is lower than the first fluid pressure input.   
     
     
         9 . The downhole packer assembly according to  claim 8 ,
 wherein the third fluid outlet comprises a second pressure-reduction valve having a second fluid pressure input and a second fluid pressure output, and   wherein the second fluid pressure output is lower than the first fluid pressure output.   
     
     
         10 . The downhole packer assembly according to  claim 8 , wherein the first fluid pressure output is at least 20 bars lower than the first fluid pressure input. 
     
     
         11 . The downhole packer assembly according to  claim 8 , wherein the first fluid pressure output is 25 bars lower than the first fluid pressure input. 
     
     
         12 . The downhole packer assembly according to  claim 8 , wherein the first fluid pressure output is 30 bars lower than the first fluid pressure input. 
     
     
         13 . The downhole packer assembly according to  claim 1 ,
 wherein the first expandable tubular element is secured relative to the second expandable tubular element by an extension tubular having a first end connected to the first expandable tubular element and a second end, and   wherein the extension tubular is configured to elongate from a first length to a second length at a predefined force threshold in a confined space.   
     
     
         14 . The downhole packer assembly according to  claim 1 ,
 wherein the first expandable tubular element is secured relative to the second expandable tubular element by a breakable tubular having a first end connected to the first expandable tubular element and a second end, and   wherein the extension tubular is configured to break at a predefined force threshold in a confined space and release the first expandable tubular element relative to the second expandable tubular element.   
     
     
         15 . The downhole packer assembly according to  claim 13 , wherein the predefined force threshold is 150 bars of pressure in the confined space. 
     
     
         16 . The downhole packer assembly according to  claim 13 , wherein the predefined force threshold is 180 bars of pressure in the confined space. 
     
     
         17 . The downhole packer assembly according to  claim 13 , wherein the predefined threshold is 200 bars of pressure in the confined space.