Method for repairing a hanger (D) of a liner (B), for making a leak-tight connection, the liner (B) being placed inside and in the continuation of the casing (A) of a well, the method consisting in axially positioning a metal tubular blank (1) in the well, the blank having a solid wall radially deformable beyond its elastic limit and comprising an upper cylindrical portion (10) whose outer diameter is slightly smaller than the inner diameter of the casing (A), a lower portion (13) also cylindrical whose outer diameter is slightly smaller than the inner diameter of the liner (B), and an intermediate portion (11, 12) of diameter varying between these two diameters, and causing radial expansion of at least one of these two cylindrical portions (10, 13) beyond its elastic limit so that they are applied closely and firmly and in leak-tight manner against the inner face of the wall opposite the casing (A) or liner (B).