Shell has begun to use 'cube development', which involves linking multiple wells to extract all the oil from a shale formation at once, rather than gradually.

Oil shale formation takes place in a number of depositional settings and has considerable compositional variation.

In the oil shale formation, the gas would cause pyrolysis, releasing shale oil vapors.

The technology has unlocked vast reserves of oil and gas in shale formations underground, transformed the energy industry and fuelled the fortunes of families.

It said that it would also test shale formations, however, and if the results were positive it would consider applying for fracking at the site.