Patent ID: 6109829
Filing Date: 2000-08-29
Classification: B29C,F16L

Abstract:
A method for installing a liner in a subsea pipeline, the method comprising the steps of:flooding the interior of the pipeline so as to apply ambient subsea hydrostatic head throughout the length of the pipeline;pulling the liner along the length of the interior of the pipeline from an upstream end thereof to a downstream end;connecting said liner to a pig which forms a substantially fluid-tight seal with the interior walls of the pipeline,applying said ambient hydrostatic head on both sides of the pig, andreducing the hydrostatic head on a downstream side of the pig such that the hydrostatic head on said downstream side is less than the hydrostatic head on an upstream side of the pig, whereby said pig is transported along at least part of said pipeline by the resultant pressure differential between said upstream and downstream sides of said pig and said liner is pulled along the interior of the pipeline by said pig.