Det Norske Veritas (DNV), Oslo, has finished its independent inventory of contaminants on board the unused Brent spar loading buoy.
Contents of the buoy became an issue in the abortive attempt to dump the structure in deep water off Northwest Britain after international protests sparked by environmental campaign group Greenpeace.
DNV, a safety and inspection body, estimated 75-100 metric tons of hydrocarbons remain on board the spar. That compares with 53 metric tons estimated by operator Shell U.K. Exploration & Production and 5,000 metric tons estimated by Greenpeace.
Greenpeace admitted its figure was based on incorrect sampling techniques (OGJ, Sept. 11, p. 22). Shell said its underestimate was due to not allowing for oil migrating from tanks to pipework above in the period since decommissioning of the spar in 1991.
Shell Expro said it commissioned the DNV study to establish the validity of the Greenpeace estimate of remaining oil and "...to investigate a sworn affidavit supported by Greenpeace which claimed that toxic waste had been hidden' in the spar."
DNV reported that the affidavit said 3 bbl of toxic waste were hidden on the spar 15 years ago. DNV said the affiant was interviewed twice but changed his explanations of what he had seen.
DNV said, "DNV inspected tank and void spaces without finding any evidence that such toxic waste was ever hidden on board. The individual who put forward allegations of toxic material being hidden on board the buoy undermined his own credibility through his behavior and changing statements."
Heinz Rothermund, managing director of Shell Expro, said, "The amount of oil in the spar calculated by DNV is still well within an acceptable range in relation to our original environmental impact assessment. The study will form another valuable input to the new way forward for the spar."
Geir Wang-Anderson, campaigner for Greenpeace International, said, "Today's information means that the best method of decommissioning the Brent spar on land can be decided properly, with all the facts before us, instead of the previous dump and hope for the best situation."
A Shell spokesman said Greenpeace's view that Shell had abandoned the option for deep sea disposal is premature. He said deep sea dumping was still the approved option and cannot be discounted until another option has been approved.
A week earlier, Shell Expro disclosed a plan to invite contractors and individuals to develop proposals for disposal or reuse of the spar. The company has received more than 200 unsolicited proposals. Copyright 1995 Oil & Gas Journal. All Rights Reserved.
