First Subsea to Moor Deepest STP Buoy at GOM's Chinook Cascade Field

Advanced Production and Loading (APL) AS has awarded subsea mooring specialist, First Subsea, a contract to supply mooring connections for a disconnectable Submerged Turret Production (STP) Buoy in the Chinook Cascade field in the Gulf of Mexico. Moored in 2,500 meters of water, the project will be the deepest application for a STP buoy supplied by APL so far.

The STP buoy will be used by a FPSO vessel supplied and operated by BW Offshore, on behalf of Petrobas, due to come into operation in 2010. First Subsea is supplying 11 Series II ball and taper Ballgrab mooring connections with a minimum breaking load (MBL) of 6,600kN. The buoy will feature Ballgrab female uni-joint connectors on its underside.

Once the STP buoy has been positioned in the field, all the male mooring line connections, linked by chain to the sea bed, are connected to the female connectors subsea by ROV avoiding the need for divers. This is a safer connection technique than traditional surface connection methods.

Pre-installing the Ballgrab female connectors on the buoy will also make it easier to lift the buoy from the installation vessel into the water, without the need to support mooring lines.

Final delivery of APL's STP buoy system for the Chinook Cascade field is expected in April 2009 and the installation campaign will commence soon after.