Extraction and Coreflow Transferal of the Prestige Fuel Oil to a FPSO: Prestige WreckFuel Recovery Project

摘要

In November 2002, the Prestige oil tanker sank in 3,850rnmeters of water depth offshore Spain carrying some 77,000rntons of heavy fuel. During the sinking, and for a period ofrnseveral months, a large amount of fuel was spilt and ended uprnmainly in the shores of Galicia (Northwest Spain). The wreckrncontinued to leak fuel at slowly decreasing rates.rnRepsol YPF, though in no way connected to the vessel orrnits cargo, was appointed by the Spanish government to recoverrnthe fuel remaining inside the wreck. Later Repsol YPFrnselected Sonsub as the main contractor.rnThe assignment faced daunting problems of depth,rnpressure and an extremely viscous product, which preventedrnthe use of conventional extraction techniques and pumping.rnDue both to very high viscosity of the fuel and to thernwreck depth, the neutralization project required the design andrnuse of novel techniques and tools, including a new batchrnextraction method involving aluminium shuttle tanks to extractrnthe fuel from the wreck and taking it up to some 60 m depthrnbefore offloading to a FSO trough a purpose designed flexiblernriser.rnThis paper describes an innovative application of the coreflowrntechnique, which was required to reduce frictional lossesrnwithin the flexible riser while pumping the highly viscous fuelrnoil from the extraction shuttles to the FSO.rnA project overview and details of other aspects of thernproject are described in separate papers, see References.rnThe Repsol YPF Prestige Recovery Project has won thernprestigious “Energy Engineering Project of the Year” award atrnthe Platts Global Energy Awards for 2004.