| 摘要 |
A method of inserting a liner (10) into a host tubular (60), in which the liner is deformed to reduce its cross-sectional dimensions; the deformed liner is fed into the host tubular in a downstream direction; and a fluid is injected under pressure into the host tubular to urge the liner in the downstream direction, while the fluid pressure maintains the deformation of the liner. The liner is advantageously deformed by at least one set of rollers (22, 23, 24) into an unstable cross-sectional shape which has at least three axes of symmetry and which spontaneously expands into contact with the host tubular unless held by the pressure of the injected fluid. The injected fluid applies a shear force to the liner in the downstream direction which is substantially uniform along the length of the liner.
|
