In the latest test at the Horse Hill site in Surrey, United Kingdom Oil and Gas has found that oil flows freely to the surface. Geographical investigates the future of the Weald Basin

Recent tests at the Horse Hill site in Surrey, one mile north of Gatwick Airport, have resurrected hopes of an ‘oil bonanza’ in Sussex. Siphoned from 900 metres below the ground to the surface, the oil flowed freely – without help from fracking or other stimulation – at a rate of 463 barrels a day. According to Steven Sanderson, CEO at United Kingdom Oil and Gas (UKOG), Horse Hill could operate at the equivalent of ‘one of the best-producing wells in the United States’. Such statements have led it to be nicknamed the ‘Dallas of Sussex’.

While the southeast of England hardly conjures images of the endless nodding pumpjacks of American oil fields, extraction is not new to the English countryside. The largest onshore well in the country – endearingly named Wytch Farm – produces oil at a rate of 20,000 barrels per day and has been operational for three decades. Around 120 other wells dotted around the country amount to two per cent of the UK’s total oil extraction, with offshore projects producing the rest. Could the Horse Hill site be joining them?

Professor of Energy at the University of Sussex, Jim Watson, remains skeptical. ‘My basic reaction is one of caution,’ he tells Geographical, ‘it is usually risky to extrapolate from limited test data – as there is in this case – about potential reserves and their accessibility. The original estimates for potential reserves by the developer have already been revised downwards. While the flow rates sound promising, it remains to be seen how accessible they will be and whether they will be commercially viable.’

The Horse Hill site sits within the Weald Basin, which been a font of excitement for investors since 2014 when initial testing indicated it could hold million of barrels worth of oil. Last April, UKOG estimated the Weald’s oil reserves to be 100 billion barrels, with 15 per cent accessible for commercial use. While this excitement was hastily scaled down for fear of disappointment, last October the figure was raised again to 124 billion, provided fracking could be used to loosen the oil from the layers of rock around it. A factor that makes the development worse in the eyes of environmentalists.

‘There is also the current low oil price to consider,’ says Watson. ‘At current prices, many of the oil fields that are producing in the North Sea are making a loss – and these are well-known fields with established operations. This will only make it harder for new production, particularly onshore, to be commercially viable. Prices may rise again in future – and many in the industry expect this – but it is hard to say whether that will happen, when, and by how much.’