Carbon Briefing: UK shale oil – what, where, and how much
- New data from the British Geological Survey (BGS) suggests there are 4.4 billion barrels of oil trapped in shale rock under southern England.
- The figure refers to shale oil, not shale gas. It also refers to the total amount in the ground rather than the amount that can be extracted, which may be just a few per cent of the total.
- The quantity of oil involved is small compared to that pumped from under the North Sea over recent decades, but large compared to known UK reserves of oil.
- The BGS published estimates of the shale gas resource in northern England last year and will publish estimates of shale oil and gas in central Scotland this summer.
- The industry has offered to pay £20,000 per well to communities affected by horizontal drilling. That payment is on top of a previously agreed £100,000 lump sum when a test well is fracked, plus one per cent of revenues from the wells.
How much oil is there?
There are billions of barrels of shale oil under the Home Counties of southern England, according to new estimates from the BGS. But there is unlikely to be any shale gas, it says.
BGS thinks there are between 2.2 and 8.5 billion barrels in the Weald basin that covers much of Sussex, Hampshire, Kent and Surrey. The best guess is 4.4 billion barrels.
The estimate is based on detailed seismic mapping and checks on 248 existing oil or gas wells. These have been combined in a model of the subsurface to estimate the total volume of oil.
Not all of the oil will be technically or economically recoverable. The BGS says:
“It should be emphasised that this figure refers to an estimate for the entire volume of oil in the rock, not how much can be recovered. It is still too early to determine how much could technically be extracted at commercial rate.”
A spokeswoman for industry body the UK Onshore Operators Group (UKOOG) tells Carbon Brief:
“It’s good to know what the estimates are but the real issue is what is technically and economically recoverableâ?¦ until there are exploratory tests we won’t know. The geology is a bit different to the US so it’s difficult to make comparisons.”
BGS says the the Weald Basin has potential oil resources “similar, but on a smaller scale, to the producing shale oil provinces of North America”. The US is thought to have 58 billion barrels of shale oil. So the UK is unlikely to replicate the success of the US’s shale revolution even if all other things were equal. But they’re not – the BGS says that the UK’s shale rocks have lower concentrations of oil than those in North America.
BGS head of groundwater science Dr Rob Ward says:
“There are estimates of [the technically and economically recoverable proportion] for the US where they’ve gone through the whole process. It varies quite considerably depending on the shale being exploited but could be in the region of a few percent.”
Oil, not gas
One of the fiercest debates over exploiting shale gas resources has been over whether it will supplant high-emission coal, or crowd out investment in renewable electricity from wind and solar. As the Weald basin resources are oil – not gas – this question does not apply.
The overall 4.4 billion barrel estimate can be compared to the roughly 45 billion barrels of oil that have been extracted from the North Sea over the past 40 years. If all of the Weald basin shale oil were recoverable – a very unlikely scenario – it could replace the North Sea resource for about four years.
The BGS figure can also be compared to the estimated 345 billion barrels of shale oil thought to be under ground – though not necessarily recoverable – around the world.
The UK uses 535 million barrels of oil each year. It has 3 billion barrels of oil that are currently known to be recoverable.
Last summer The Times reported that the estimated quantity of shale oil in the Weald basin would be substantially smaller. It said the BGS would put the figure at hundreds of millions of barrels, not billions.
Where is it?
The UK’s shale rock covers most of the country. Today’s report focuses on the south of England in an area called the Weald Basin (the purple part of the map below). A previous report surveyed resources in north and central England.
Image - BGS shales map (note)
Source: BGS/DECC, The Jurassic shales of the Weald Basin: geology and shale oil and shale gas resource estimation report
The Weald Basin has five sections of shale rock that could contain oil, at different depths. The inner coloured lines on this map show where those sections are:
Image - BGS Weald Basin (note)
Source: BGS/DECC, The Jurassic shales of the Weald Basin: geology and shale oil and shale gas resource estimation report
As it stands, any company holding a conventional oil and gas license can apply to frack. The map below shows which parts of the country the government is currently considering offering licenses to operate in. As you can see, it covers most of the country:
Image - 1-licenses (note)
Source: Carbon Brief map using Department of Energy and Climate Change data
But that doesn’t mean all of the resources will be extracted. There are a number of hurdles companies will have to clear before they can get fracking.
Local opposition is likely. The Telegraph this morning reported that the chairman of Sevenoaks Conservative Association – which lies within the BGS study area – said he would be “uneasy” about frackers moving into his area. Other influential Conservatives – such as George Osborne’s father-in-law and former energy minister Lord Howell – are also against drilling in the UK’s green and pleasant south.
The UK’s geology could also be an obstacle. UK shale is thicker than in North America, with many different types of rock irregularly layered on top of each other, making it harder to extract the oil and gas.
The industry has also complained about the length of time it takes to get clearance to frack. A House of Lords report earlier this month called on the government to simplify the system, cutting the time it takes to get approval from 18 months to six.
New compensation
The government has also announced a couple of policies it hopes will help the shale gas industry.
Residents will no longer be able to hold up drilling applications using trespass laws. The laws were considered to be a nuisance to shale oil and gas companies wanting to drill horizontally – under people’s houses – although DECC says the Secretary of State often forced plans through in the national interest.
In return for the easier access, the government announced the industry was willing to make voluntary payments of £20,000 to communities hosting a horizontal drill. That payment would be on top of an already agreed package to compensate communities with a lump sum of £100,000 when a test well is fracked, plus one per cent of eventual revenues from the wells.
Some reports suggest communities could stand to gain as much as £800,000 from the deal. The total depends on how many wells are drilled and how productive they turn out to be. Industry sources told the Telegraph they only expected to pay in the region of £200,000, however.