Method for sealing between a lining and borehole, casing or pipeline

Method of sealing the peripheral space between an interior lining and an exterior cylindrical borehole, casing or pipeline in which it is accommodated, the lining being obtained from a radially deformable flexible wall tubular preform adapted to be hardened in situ, said preform being adapted to occupy a first or contracted state in which its greatest transverse dimension is substantially less than the inside diameter of said borehole, casing or pipeline and a second or expanded state in which its external surface has a cylindrical shape with a diameter substantially equal to the inside diameter of said borehole, casing or pipeline, said preform being hardened when it is in said expanded state within said borehole, casing or pipeline so that it forms a rigid lining, in which method, when said preform is in said contracted state, at least one elastically deformable annular seal is placed around it, said seal having imparted to it a configuration which does not impede insertion of said preform into said borehole, casing or pipeline, after which said preform with its seal is installed inside said borehole, casing or pipeline, after which said preform is radially expanded, one effect of which is to expand said seal at the same time as an annular groove is formed in line with it in the exterior surface of said preform, and finally said preform is hardened to provide a rigid lining having a seal integrated in said groove.