Scientists warn carbon capture scheme could trigger North Sea earthquakes

Peterhead Power Station
Peterhead Power Station

Experts have warned that earthquakes could be triggered near North Sea pipelines and platforms if plans to store carbon emissions under the seabed go ahead.

Academics have written to MPs to outline the “risk” that using offshore oil and gas reservoirs for carbon capture and storage (CCS) schemes could cause seismic activity.

The CCS project at Peterhead aims to capture carbon dioxide at the power station then pump it into a depleted gas field.

The green-energy scheme is poised to win up to £1billion of UK Government funding and create 1,000 jobs, while several other CCS initiatives in the UK also propose storing emissions in the North Sea.

But geophysicists have told the energy and climate change committee at Westminster that injecting such a large volume of fluid into the seabed “has the potential to trigger earthquakes”.

READ MORE: £1bn Peterhead CCS bid at risk from independence, warns new Scots Secretary

The three Bristol University academics also said that it could “reactivate faults and fractures”, causing the stored CO2 to start leaking.

They did not call for the projects to be abandoned, but made a series of recommendations for extensive risk assessments to be carried out and urged careful monitoring of the sites.

The UK Government insisted last night that it had a “rigorous” assessment process in place.

The concerns have been raised just days after it was reported that more than 500 minor tremors have been felt in towns across a 125-mile stretch of coast in Spain.

The largest measured 4.2 on the Richter scale.

The quakes were blamed on a recent injection of gas into a depleted oil reservoir one mile beneath the seabed and could leave Spanish authorities facing a hefty compensation bill.

James Verdon, a geophysicist at Bristol University, is one of the academics who has written to MPs as part of their inquiry into CCS.

He said: “If there is a fault nearby, the added pressure of the injection of fluid can trigger earthquakes. I think 95% of sites probably won’t trigger seismic activity – but one might and we should prepare.

“It’s unlikely but it is a risk and with anything that is a risk, you need to understand it.

“The point of my evidence was not to say this is a project-killer for CCS sites, but it is important that we conduct the right risk assessments.

“There is still infrastructure offshore.”

Mr Verdon added that he believed “the bigger risk” to CCS sites was that the cap rock could fracture and leak CO2, defeating the purpose of the schemes.

Energy giants Shell and SSE are driving forward a plan to develop CCS at Peterhead’s gas-fired power station. It would capture 90% of the carbon dioxide from part of the power station before transferring it to a gas field.

The proposal is one of two preferred bids for £1billion of funding, along with a coal-based scheme at Drax in North Yorkshire, which involves storing the emissions in a saline aquifer beneath the southern North Sea.

Two reserve bids also propose using North Sea fields to store CO2.

Frank Doran, Labour MP for Aberdeen North, said of the earthquake warning: “I don’t doubt that these are risks but I do think that they are remote risks.

“There’s a huge amount of experience in the North Sea of injecting sample water as part of enhanced recovery techniques. I think CO2 will be exactly the same. It’s replacing fluids that have been taken from the field.

“I’ve got confidence in the geologists and others who make these decisions.”

A spokesman for the Department of Energy and Climate Change said: “We have a rigorous assessment process for considering applications for offshore CO2 storage, such as for the Peterhead CCS project.

“This assessment takes into consideration the geological suitability of the storage site and would include an evaluation of any potential seismicity to ensure the safe and permanent storage of CO2.”

A spokeswoman for Shell declined to comment on the academics’ warning last night.