| 摘要 |
<p>The application discloses a method for laying a pipeline of joined sections of steel pipe having a corrosion resistant metallic or other liner. The method comprises: laying the pipeline from a pipelaying vessel by joining together sections of pipe; sealing a length of the pipeline using first and second seals; flooding the length of the pipeline between first and second seals with a fluid and pressurising the fluid; and causing the first and second seals to move relative to the pipe as the pipeline is laid to maintain a locally increased internal pressure in a section of the pipeline in which the liner is at risk of wrinkling due to bending of the pipe. The locally increased internal pressure may be maintained in a section of the pipe that is subject to elastic deformation and/or plastic deformation. The locally increased internal pressure may be only applied in sections of the pipeline in which the metallic liner is at risk of wrinkling due to bending of the pipe. Sections of the pipeline other than the section subject to the locally increased internal pressure are preferably laid in the substantial absence of internal pressure. The first and second seals may be caused to move relative to the pipe by operation of independently driven mechanical conveying means provided inside the pipe. Alternatively, the first and second seals may be caused to move relative to the pipe by tethering the seals to a fixture unmovable relative to the pipe as it is being laid.</p> |
