| 摘要 |
The invention relates to a method of fabricating and installing a riser tower structure comprising the steps of installing a central core 210 and means 220 to tension the core, such that the central core extends from the seabed toward the surface and is suspended by the tensioning means at, or near the sea surface, thereby forming a central core structure. An elongate conduit 285 is then lowered on a line 290 and suspended from an upper part of the central core structure. The suspended elongate conduit is located into guide means 240 located at one or more points along the length of the central core. The previous steps are then repeated for successive conduits. Following installation of the elongate conduits, the method further includes lowering a flexible conduit (700 figure 7) from the surface to the top end of one of the elongate conduits, the flexible conduit thereby connecting a respective elongate conduit to a surface facility. This last step is repeatable for the other elongate conduits to connect all of them to a surface facility. The invention also relates to a buoyancy device that enables the step-by-step location of the elongate conduits, a guide frame mountable to the central core to guide the suspended elongate conduits and a pulley system to aid locating the conduits into the body of the guide frame. |
