A rule placing liability on operators for any post-decommissioning incidents could be a “key part” of the Shell Brent debate, according to a petroleum economist.
Under current regulations, oil firms have what is known as “residual liability” meaning they have to deal with any problems which occur after decommissioning.
Some countries have expressed concern over the potential environmental impact of oil storage cells in the legs of Shell’s Brent platforms if they are kept in place, as well as the risk to marine traffic.
The Brent field was also subject to Greenpeace protests earlier this week.
However professor Alex Kemp of Aberdeen University highlighted that if anything were to happen, Shell will have liability “in perpetuity”.
He added: “The rules are that the current operators have a residual liability to deal with any problems which can emerge. That could include leaks, other accidents with ships hitting the remains, etc.
“Residual liability in perpetuity exists at present. That means that the companies concerned have an obligation to deal with any accidents which cause damage.
“These obligations exist and if there was something terrible happened with the remains which had been agreed to stay in place under a decommissioning plan, then the companies have this obligation to take responsibility for it.”
The Brent legs are giant structures which were not at the time built for removal, as regulations did not dictate the need to do so.
There have been examples in the past of “derogation” being granted for these types of platforms, namely the Frigg field on the UK-Norway maritime border.
Professor Kemp added: “It’s only in more recent years that when a field development plan is consented it has to be shown at the time that the whole platform can be removed.
“When those fields like Frigg or Brent were given development approval way back in the 70s, that regulation was not in place. That only came into the rules after Brent Spar.
“Historically (the UK) has followed Ospar rules which in general want a clean seabed but there are derogations in certain circumstances.
“Derogations are available, for example, when the legs of a concrete platform are allowed to remain in place because the costs and the safety effects of complete removal were felt to be extremely high.
“We’ve also got a derogation for footings which are above 10,000 tonnes which may be left in place as well.”