Portfolio
2003 BP Na Kika FDS

Click on the image for larger view

The Na Kika host is moored in a water depth of approximately 1936 m (6350 ft) and is the deepest permanently moored floating production facility in the world. The engineering and procurement of the mooring and the installation of the mooring and host involved a focused effort over 3 ½ years.

Engineering and planning for the mooring and installation of the Na Kika platform commenced in earnest at the beginning of 2000, shortly after the selection of the semi-submersible as the host concept, and at the time that the overall arrangement and sizing of the hull was being finalized.

Mooring system optimization studies evaluated alternative arrangements using polyester and steel mooring lines, and considered buoyed and un-buoyed systems with 12 and 16 mooring lines. For this application, polyester lines did not offer an overall cost advantage, nor did the use of submerged buoys in the mooring lines. Accordingly a semi-taut system with steel spiral strand wire lines was selected. Each line included a length of ground chain from above the mud line touchdown point to the anchor piles, and a short length of platform chain for the top connection to the platform. A twelve line mooring would have required wire and chain sizes at the limits of proven production capabilities and did not offer significant cost advantage over a sixteen line system which was selected. The system was configured with four closely spaced lines at each corner of the hull with space between the mooring groups to allow free access for riser and umbilical hook up to the hull pontoons. The field layout is such that there are more risers on the north of the platform so the south side mooring lines were made longer to balance the larger riser load to the north.