A NORTH-EAST expert has urged caution after reports that the UK may be set for an oil bonanza - as it may be difficult to extract from the ground

Andrew Aplin, professor of unconventional petroleum at Durham University, was commenting on the British Geological Survey (BGS)/Department of Energy and Climate Change report into the potential for oil extraction from the Weald area of Sussex, Hampshire, Kent and Surrey.

Prof Aplin said: “The interesting question is how much of the oil that has been identified might be recoverable. A careful look at the data in the report suggests that much of the oil in the shales is tightly bound to the rock and therefore difficult or impossible to produce.

“If there is any free – and therefore potentially producible – oil in the shales, there are two further problems.

“Much of the shale sequence in the Weald is clay-rich, which US experience suggests is difficult to fracture effectively.

“Also, the chemistry of the oil in much of the area is likely to be quite heavy and thus will not flow easily; in contrast, the shale oil which is being currently produced from areas such as the Eagle Ford in the USA is much lighter and thus flows more easily.

“The BGS report suggests that a total of five billion barrels of oil may be present in Weald shales. However, data from the US suggests that, at best, only five percent of the oil may be extracted from shale.

“Since neither the rock nor the oil is of optimal quality in the Weald, we might estimate that one per cent of the Weald oil resource might be recoverable.

“This would equate to 0.05 billion barrels, which is about two months UK consumption. From a national perspective, this seems to be a rather small prize.”