| 摘要 |
A method is disclosed for installing a pipeline riser on an offshore structure situated in a body of water. The technique includes laying a pipeline on bottom having a free end adjacent the base of the structure, positioning a floating vessel over the pipeline, and connecting at least one tension member between the vessel and the pipeline. The free end of the pipeline is raised to a point adjacent the water surface by applying force to the pipeline through each said tension member having a magnitude and direction such that the sum of the vertical force components is sufficient to lift the free end of the pipeline and the sum of the axial components is sufficient to prevent bending stress in the unsupported suspended section from exceeding the allowable stress. A riser bend section is attached to the free end of the pipeline and the pipeline lowered to the bottom as additional sections of the riser are attached. Simultaneously, sufficient axial tension is maintained on the pipeline to prevent the suspended section from being overstressed.
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