Tubular element with dynamic sealing and method for applying same against the wall of a wellbore

A device for isolating part of a wellbore, wherein it comprises a pipe provided over a section of its outer surface with at least one outer radially expandable metal tubular element having on its outer surface a series of spaced apart annular sealing modules, wherein each sealing module comprises two annular metal abutments between which there are inserted an annular seal and two anti-extrusion rings, the seal being positioned between the two anti-extrusion rings, and the two metal abutments being fixedly secured against the outer surface of the said radially expandable metal tubular element, wherein the two anti-extrusion rings are made in elastically and plastically deformable material and are in one or two parts and wherein the two anti-extrusion rings and/or the seal comprise at least two opposite facing bevelled surfaces capable of sliding relative to one another under the effect of axial movement of said seal, so as to cause radial outward displacement of one of the anti-extrusion rings or at least one of the two parts thereof,

• wherein the opposite ends of this radially expandable metal tubular element are secured to the said outer surface of the pipe so as to delimit an annular space between the outer surface of the pipe and this radially expandable metal tubular element, the wall of the said pipe having at least one opening causing it to communicate with the said annular space, the metal tubular element being radially expandable so that over part of its length with the exception of its ends it is sealingly applied against the wall of the wellbore.

A method for sealingly applying a radially expandable metal tubular element against the wall of a wellbore or casing in place inside this wellbore, this element being previously positioned inside the said wellbore or said casing, this radially expanding metal tubular element having on its outer surface a series of spaced apart annular sealing modules, wherein each sealing module comprises two annular metal abutments between which there are inserted an annular seal and two anti-extrusion rings, the seal being positioned between the two anti-extrusion rings, and the two metal abutments being fixedly secured against the outer surface of the said radially expandable metal tubular element, wherein the two anti-extrusion rings are made in elastically and plastically deformable material and are in one or two parts and wherein the two anti-extrusion rings and/or the seal comprise at least two opposite facing bevelled surfaces capable of sliding relative to one another under the effect of axial movement of said seal, so as to cause radial outward displacement of one of the anti-extrusion rings or at least one of the two parts thereof, wherein the method comprises the following steps:

• a) radially expanding the said metal tubular element under a first pressure P1 until the central sealing modules come into contact with the said wall;
• b) applying an increasing overpressure ΔP for a predetermined time until the sealing modules positioned either side of the central modules progressively come into contact with the said wall from the centre towards the ends of the tubular element,
• c) releasing the said pressure inside the said metal tubular element, the annular seals remaining in contact with the wall of the wellbore or casing.

The method for sealingly applying an isolating device against the wall of a wellbore or casing placed inside this wellbore, this device previously being positioned inside the said wellbore or said casing, said isolating device comprising a pipe provided over a section of its outer surface with at least one outer radially expandable metal tubular element having on its outer surface a series of spaced apart annular sealing modules, wherein each sealing module comprises two annular metal abutments between which there are inserted an annular seal and two anti-extrusion rings, the seal being positioned between the two anti-extrusion rings, and the two metal abutments being fixedly secured against the outer surface of the said radially expandable metal tubular element, wherein the two anti-extrusion rings are made in elastically and plastically deformable material and are in one or two parts and wherein the two anti-extrusion rings and/or the seal comprise at least two opposite facing bevelled surfaces capable of sliding relative to one another under the effect of axial movement of said seal, so as to cause radial outward displacement of one of the anti-extrusion rings or at least one of the two parts thereof,

• wherein the opposite ends of this radially expandable metal tubular element are secured to the said outer surface of the pipe so as to delimit an annular space between the outer surface of the pipe and this radially expandable metal tubular element, the wall of the said pipe having at least one opening causing it to communicate with the said annular space, the metal tubular element being radially expandable so that over part of its length with the exception of its ends it is sealingly applied against the wall of the wellbore,
• wherein the method comprises the following steps:
• a) radially expanding the said metal tubular element under a first pressure P1 until the central sealing modules come into contact with the said wall;
• b) applying, for a predetermined time, an increasing overpressure ΔP until the sealing modules positioned either side of the central modules progressively come into contact with the said wall from the centre towards the ends of the tubular element;
• c) releasing the said pressure inside the said metal tubular element, the annular seals remaining in contact with the wall of the wellbore or casing;
• d) applying a pressure P4 in the annular space arranged between the pipe, the wall and two successive metal tubular elements until the seal is axially moved against one of the anti-extrusion rings causing outward radial displacement of the latter or of one part thereof so as to fill the clearance existing between the metal abutment and the wall of the wellbore.