But despite the scale of emissions that may be leaking from abandoned wells, these emissions are not currently being monitored by regulators or operators.
Methane is a more potent greenhouse gas than carbon dioxide, and – pound for pound – can trap much more heat in the atmosphere over the course of a couple of decades.
The study comes as operators begin planning for the end of oil and gas extraction from the North Sea – over the next couple decades hundreds of oil rigs will need to be decommissioned. Yet, under current rules, operators are not required to monitor inactive or abandoned wells, opening up a regulatory gap as the North Sea moves into a new phase.
As the study’s authors write: “Our and other recent studies clearly document strongly increased CH4 [methane] emissions in areas with oil and gas operations, which may counteract our efforts to reduce greenhouse gas emissions by switching supply from coal to gas.
“Therefore, it is important to improve our surveying and monitoring efforts and adapt the respective regulatory frameworks (national and international), because the regional aggregate of thousands of wells with fairly low gas flows can be substantial.”
The study measured three abandoned offshore wells in the Central North Sea where shallow gas pockets were releasing methane. From this they were able to create a model to measure the impact across the region at depths limited to the upper 1000 meters of the ocean sediment.
Due to the shallow depths at which the methane is released, not all of it remains in the oceans. The scientists found that a large portion — 42 percent — of the methane emissions leaking from the abandoned wells reach the atmosphere where they will contribute to rising temperatures………
More and better data is needed in order to start addressing this issue of so-called fugitive emissions, Haekel argued. He and his team plan to make another trip to the North Sea this month to continue gathering more data from other wells.
The CCC is also planning to study the issue of fugitive emissions from conventional petroleum production both onshore and offshore.
“We need these numbers to have a proper discussion about energy conversion, going from oil and gas and coal to renewables,” Haeckel said, adding that the wells his team are studying in the North Sea are just one part of the bigger picture.https://www.desmog.uk/2017/09/04/abandoned-north-sea-wells-may-be-emitting-significant-amounts-methane-study-warns
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