Shell is planning to leave behind concrete and steel structures as big as the Empire State Building when it abandons one of the North Sea’s largest gas and oil fields.

The company has a decommissioning plan in place for the Brent field, which is situated 115 miles to the north east of the Shetland Islands and will require international regulations to exempt it, demanding that all traces of gas and oil production will be removed after its offshore operations come to a close.

Earlier in the week, Shell said that it had finished assessing the environmental and safety risks that are involved in the removal of a significant amount of the infrastructure at the Brent field site and found that it would far outweigh the benefits.

The oil giant plans to submit its proposals to be approved by the UK’s Department for Energy and Climate Change before the conclusion of this year.

This case will be a key test of the rules on what should happen to abandoned gas and oil fields in the North Sea as the coming decades are set to see more and more energy groups decommissioning sites due to reserves becoming scarcer.

North East Atlantic countries are bound by the Ospar regulations which were agreed after the debate in the 1990s over Shell’s abortive plans to dump its Brent Spar oil storage facility just off the Scottish coast.

However, there are exemptions to the ‘leave no trace’ rule which allow companies to dump facilities if they are able to show that a full removal of the structure would either be too risky or too problematic.

Shell is using this exemption as its case for hundreds of thousands of tonnes of steel and concrete subsea structures underneath its four Brent platforms.

Decommissioning facilities in the North Sea has continued to climb the industry agenda over recent years due to the rapid fall in oil prices.