Prominent geologist expresses pessimism over likely size of UK shale hydrocarbon reserves
17 August 2017
Professor John Underhill of Heriot-Watt University in Scotland has said the UK's potential shale deposits are likely to be far smaller than originally forecast because of fundamental geological realities that have not been taken into account up until now. In the light of this, he said the government would be wise to formulate a Plan B to fracking for future gas supplies.
UK shale test drilling pad - Image: Cuadrilla
Prof Underhill said that, according to research based on seismic imaging of the country’s underlying geology, pockets of hydrocarbons were likely to be small and fractured, because most of the areas in which deposits of onshore unconventional gas and oil are likely to be found were affected by tectonic activity along the Atlantic plate about 55m years ago.
This process has buckled and depressurised these pockets, making them cooler than the optimal temperatures for oil and gas production. In the USA, shale structures are far from tectonic plate edges and have retained their thickness and integrity, retaining plentiful reserves.
The British Geological Survey found in 2013 that there were likely to be 1,300 trillion cubic feet of gas buried beneath the ground, but said nothing about how much of it might be accessible. Underhill argues the amount in suitable areas may be much less. “My challenge is: does the geology stack up?” he said.
The body representing the UK’s shale gas industry, UK Onshore Oil and Gas (UKOOG), said more exploration was needed. Ken Cronin, the chief executive, said: “The industry is currently in the process of seismic surveying, core drilling and flow testing in various parts of the country to determine a number of questions including the extent of the geology and whether gas will flow commercially.