A&P Constructs Usan Mid-water Arches

12 January 2011

A&P Group’s ship repair yard in northeast England has won a contract to build two subsea arches for Total’s deepwater Usan project, 100 km (62 mi) offshore Nigeria.

The mid-water arches, fabricated from steel and polymer materials, are buoyant support structures. They will be tethered to the seabed to support pipelines/risers transporting oil from the wellheads to Usan’s moored FPSO.

A&P will cut, shape, weld, and assemble the 12-m (39-ft) high, 25-m (82-ft) long structures around large polymer buoyancy units.

The consignment is due to be completed in March, when the arches will sail out of the River Tyne to their location on the Usan field, in water depths of up to 850 m (2,789 ft).