The British Geological Survey and Department of Energy and Climate Change published data Friday on the Weald basin in the southeast of the country.
It said there may be between 2.2 billion and 8.5 billion barrels of shale oil in place, with its central estimate at 4.4 billion barrels.
"No significant gas resource is recognized using the current geological model," a BGS statement read. "This is mainly because the shale is not thought to have reached the geological maturity required to generate gas."
For oil, BGS said its estimate represents the total amount of oil locked in shale deposits and is not a representation of what's commercially extractable for energy explorers.
British Energy Minister Michael Fallon said Friday the government launched a consultation process to make it easier for companies to drill into shale gas and oil deposits.
"Britain needs more home-grown energy," he said in a statement. "Shale development will bring jobs and business opportunities."
Shale exploration in the country is in its infancy.
British Friends of the Earth campaigner Brenda Pollack said BGS shale oil estimates will "set alarm bells ringing" though communities worried about hydraulic fracturing, the controversial drilling practice dubbed fracking.
"Rather than drilling for more dirty fossil fuels that will add to climate change, the government should be backing renewable power and energy efficiency," she said in a statement.