Jan De Nul N.V. dredging company participates on “Sakhalin‐III”
After JDN’s contributions in the developments of the oil and gas fields of Sakhalin‐I (DeKastri, Tatar Strait, Chayvo, Orlan) and Sakhalin‐II (Nakhodka, Prigorodnoye, Lunskoye, Piltun) JDN’s involvement in the new subsea development at the Sakhalin‐III Kirinskoye Gas and Condensate Field, exploited by Gazprom, was sealed by the signature of a new contract with MRTS in June 2011.
Impressive fleet mobilised
Only one month after contract signature, the trailing hopper dredger ’Leiv Eiriksson’, the largest dredger in the world, the trailing hopper dredger ’Francis Beaufort’ and the selfpropelled seagoing cutter dredger ‘Fernão De Magalhães’ were mobilised to Sakhalin. These vessels completed the 28.5 km long trench from the offshore Kirinskoye field at 90 m water depth to the cofferdam on the beach to allow the installation of a 4,5” MEG line, a 20” export pipeline and a controls umbilical.
In the offshore field, TSHD ’Leiv Eiriksson’ also dredged at 90 m waterdepth five areas to about 4m deep to replace weak soil on which the 6 subsea wells, the manifold and other gas gathering facilities were to be safely installed without the risk of liquefaction in case of a subsea earthquake.
By mid August, the fallpipe vessel ‘La Boudeuse’ joined the fleet whose first task has been to fill up the soil replacement areas with rock supplied by the main contractor. The vessel is also to install rock on the pipelines for protection against ice scouring and stabilization. The dredgers then have to backfill the remainder of the trenches with sand to protect the pipelines from storms and sea ice.
Completion in 2012
Although weather has been favourable, the unavoidable end of the Sakhalin working season is closing in. The remaining scope will be executed during the summer season of 2012.
Excavation work at Chaivo for Exxon.
Also during the 2011 summer season, excavation work at Exxon’s dock facility at Chaivo have been executed and successfully completed. More than 200.000 m3 of soil has been removed and place in an offshore berm.
