Method of reeling and unreeling an internally clad metal pipeline

A method for reeling or unreeling a pipeline having an inner corrosion-resistant metallic liner that is tightly fitted within the pipeline, wherein, to minimize or avoid wrinkling of the liner during the reeling or unreeling, the method comprises the following steps:

• providing a fluid connection between the pipeline and pumping/pressurizing equipment via a manifold mounted on a flange of a pipe laying reel;
• internally pressurizing a length of the pipeline in a two-stage pressurizing process, in the first stage of which the length of the pipeline is filled with fluid at a first elevated pressure and in the second stage of which the fluid pressure of the fluid filling the length of the pipeline is raised from the first elevated pressure to a second pressure that is greater than the first pressure;
• and
• unreeling the length of the pipeline while pressurized to the second pressure or connecting a leading end of the pipeline to a reel via the manifold and reeling the length of the pipeline while pressurized to the second pressure.

A method of pipe laying in which a pipeline is unreeled from a pipe laying reel on a pipe lay barge, the pipeline having an inner corrosion-resistant metallic liner closely fitted within an outer pipe that is less corrosion-resistant, and the pipeline being filled with an internal fluid pressurized to a first absolute pressure of 5 to 25 bar, the method comprising the operations of:

• providing a fluid connection between the pipeline and pumping/pressurizing equipment via a manifold mounted on a flange of the pipe laying reel;
• pressurizing the pipeline by raising the pressure of the internal fluid filling the pipeline from the first absolute pressure to a second absolute pressure of at least 25 bar;
• unwinding the pipeline from the reel while the absolute pressure of at least 25 bar is maintained in the pipeline;
• laying the pipeline on the seabed;
• and
• depressurizing the pipeline.