UK’s shale gas wells to be plugged

Article by Amanda Doyle

THE Oil and Gas Authority (OGA) has ordered that the UK’s only shale gas wells must now be sealed.

The two shale gas exploration wells were drilled at the Preston New Road site in Lancashire by fracking company Cuadrilla, which is a subsidiary of AJ Lucas.

The wells were drilled to a depth of 2.25 km into the Bowland Shale, and then horizontally for a further 0.75 km each. High quality natural gas was confirmed through fracturing and flow testing of each well. However, the process caused multiple tremors, culminating in a magnitude 2.9 tremor in August 2019 which reportedly caused damage to local buildings. Fracking was then suspended at the site and didn’t resume due to the UK Government introducing a moratorium on fracking in November 2019.

The OGA’s regulations state that redundant wells must be managed efficiently, including plugging at the end of the well’s useful life. According to AJ Lucas the surface pipework and valves will be removed from the site in addition to plugging of the wells.

Andrew Purcell, Chairman of AJ Lucas, said: “We are proud of the pioneering role played by AJ Lucas and its subsidiary Cuadrilla in validating the presence of a very high-quality natural gas resource in the Bowland shale. It is widely acknowledged that natural gas will continue to play a key role in UK energy supply for many decades to come, even as the country transitions to a net zero CO2 economy. We remain convinced that the Bowland shale gas resource has the potential to be a very significant contributor to UK energy supply and in particular a source of cost-effective fuel for heating UK homes and businesses.

“Recent announcement of significant Government funding for two Carbon Capture and Storage Hubs, one offshore North-West and the other offshore North-East England, could and should be combined with a joined-up plan to explore and exploit the adjacent onshore shale gas resources. If not, the UK’s ongoing gas needs will increasingly be supplied by long distance imports on ships.”

AJ Lucas said that it was retaining its shale exploration licences, and added that the Preston New Road site only represents a tiny fraction of the exploration licence. It said that other potential sites can be evaluated “as and when the moratorium is lifted”.

Francis Egan, CEO of Cuadrilla, said: “Cuadrilla has spent hundreds of millions of pounds establishing the viability of the Bowland Shale as a high-quality gas deposit. Shale gas from the North of England has the potential to meet the UK’s energy needs for decades to come, yet ministers have chosen now, at the height of an energy crisis, to take us to this point. Once these wells are filled with cement and abandoned it will be incredibly costly and difficult to rectify this mistake at the PNR site.”

However, this view is not reflected by the Government. A spokesperson for the Prime Minister told the BBC that shale gas was not a short-term fix and that domestic energy sources should cause minimal damage and disruption in the local area. They added that even if the moratorium was lifted, there would be insufficient supplies of gas to address the high costs of gas across Europe.

A 2018 study on the economic viability of UK shale gas as a fuel for electricity generation up to 2030 found that shale gas would have little effect on energy prices and consumer bills. A separate study published in September last year performed a detailed analysis on the risks of fuel supply chains. It determined that unconventional gas – which includes shale gas – has the highest risk of all fuels in the UK. Renewables have the lowest overall risk.

Adisa Azapagic, IChemE Fellow and Professor of Sustainable Chemical Engineering at the University of Manchester, said: “One can always argue about the economics of any energy option as it’s always so volatile and dependent on so many factors. However, we can’t hope to achieve net zero if we continue to rely on fossil fuels – shale or conventional gas – it doesn’t matter.”

Article by Amanda Doyle

Staff Reporter, The Chemical Engineer

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