Patent ID: 8235075
Filing Date: 2012-08-07
Classification: E21B,Y10T

Abstract:
1. A method of patching a well or a pipe having a zone for treatment by hydroforming a tubular metal patch of initial diameter that is considerably smaller than that of the well or the pipe, the method comprising the following steps: axially inserting inside said patch a tool comprising a mandrel on which are mounted two inflatable packers that can be expanded radially under the action of internal hydraulic pressure, these two packers being axially spaced apart from each other by a distance that is substantially equal to or a slightly less than the length of the patch; positioning said tool inside the patch with the packers in register with end portions of the patch; axially inserting in the well or the pipe an assembly comprising the tool and the patch, and positioning the assembly in register with the zone to be patched; inflating said packers under high pressure sufficient to cause the end portions of the patch to expand radially and to be pressed in leaktight manner against the inside wall of the well or the pipe; and deflating said packers and withdrawing the tool from the well or the pipe, wherein the patch comprises a central portion and mechanically reinforced end portions, the mechanically reinforced end portions having a thickness greater than the thickness of the central portion so that their resistance to deformation in radial expansion is greater than that of the central portion.