Large amounts of methane leak into North Sea from abandoned oil and gas wells – study

Large amounts of methane, a major greenhouse gas, are leaking into the North Sea from abandoned oil and gas well, according to a study by the German ocean research centre GEOMAR in Kiel published in the International Journal of Greenhouse Gas Control. The study confirms initial findings from 2012 and 2013, when scientists noticed methane bubbles were leaking from seabed areas around abandoned wells. During visits in 2017 and 2019, researchers noted leaks at 28 out of 43 wells they examined. The gas ultimately originates from pockets beneath the sea floor, they wrote. “The results clearly show that thousands of tons of methane are leaking from old drill holes on the North Sea floor every year,” said Christoph Böttner, the study’s main author. The study covered 20,000 square kilometres of seafloor, where 1,792 wells are located. Given the size and position of gas pockets, the area has the potential to emit between 900 to 3,700 tonnes of methane annually, the report said.

Methane – the main component of natural gas – is a more potent greenhouse gas than CO₂, especially when looking at shorter time horizons. Leaks along the entire value chain of oil and gas production, processing, transport and use have to be considered for the fuel’s full carbon footprint.

A separate Greenpeace study on the North Sea oil and gas extraction published this week said that oil and gas platforms in the area emitted some 30 million tonnes of CO₂ in 2017—nearly as much as Denmark’s entire emissions, while polluting waters with 9,200 tonnes of oil and 182,000 tonnes of chemicals as a result of their regular operations.