The main SURF projects executed in Sonamet are:
Girrasol: AMG/Total (2002 )
Greater Plutonio: Sotraplex/BP (2006)
Tombua Landana: Acergy/Chevron (2007)
Exxon Gas Gathering: Exxon (2008)
Pazflor: Acergy/Total (2009)
CLOV: Subsea 7/Total (2012)
GES: Subsea 7/BP (2013)
Lianzi: Subsea 7/Chevron (2014)
Zinia: Subsea7/Total (2020)
CLOV is the largest SURF project ever executed in Sonamet. The scope of work included:
•130 km of flow lines made of 4000 double joints and 3300 pipe in pipe including:
10/14 and 12/16’’ production Pipe-in-Pipe
10 and 12’’ water injection flow lines
12’’ gas export lines to the Angolan LNG trunk line
•2 Hybrid Riser Towers, one for each production loop
•1 Single Riser Tower at the end of the gas export line
•53 Subsea Structure (FLETs, ILTs, SIV)
•3 Riser Tower Suction piles
•3 Buoyancy tanks
•37 Spools and 15 Jumpers
•2 Subsea Mid-Water Arches
HYBRID RISER TOWER
CLOV SURF’s hybrid riser tower is a complex and effective system with a mix of materials to minimize the weight of the structure and simplify the fabrication and installation process.
Each HRT fabricated in Sonamet yard, weighed approximately 2700 mT and is comprised of:
•1 buoyancy tank of 55 m long and 6m diameter
•1 Upper Riser Tower Assembly (URTA)
•1100m long bundle
•1 Lower Riser Tower Assembly (LRTA)
•1 suction pile.
The two Riser Towers featured different designs and therefore required specific attention.
Numerous sub-assemblies were required to assemble the risers’ bodies.
PIPE IN PIPE
CLOV’s production lines required the onshore fabrication of 3300 units of double jointed pipe-in-pipe.
Each PiP was composed of:
•an inner double joint, wrapped with an insulated panel,
•which is then inserted into an outer double joint
•the extremities are then swaged and welded
To improve the efficiency of the PiP lines fabrication, Sonamet designed, fabricated and commissioned a brand new workshop in order to fabricate these new items. In addition, Sonamet developed new procedures to meet the highest quality standards while maintaining a high level of productivity.