A British energy company said Wednesday shale oil continued to flow naturally to the surface, a day after it declared high rates from its Horse Hill license.

Light, sweet crude oil was flowing naturally to the surface one day after U.K. Oil & Gas Investments said oil was coming up from the surface at a controlled rate of 456 barrels of oil per day.

Located near the airport of the same name, the company dubbed the flow the "Gatwick Gusher."

"The well continues to produce high quality oil at good rates," the company's chairman, Stephen Sanderson, said in a statement. "Although further work is required to be done, we are now beginning to establish the commerciality of the project earlier than originally anticipated."

The Horse Hill site is onshore north of the airport. The company said the flows are the first ever confirmed in the Weald basin limestone, which shows onshore basins may be lucrative, but comes as the country frets over a possible hydraulic fracturing industry. The practice, dubbed fracking, is viewed as a threat from environmental groups who fret over potential impacts ranging from contaminated water to earthquakes.

For Sanderson, the find could pan out to be one of the largest onshore discoveries made in the country in the last 30 years. Preliminary estimates made by the company last year put the entire Horse Hill reserve total as high as 100 billion barrels of oil.

The company said the reserves at Horse Hill are in shale beds that are fractured naturally, meaning extraction may be carried out using conventional techniques. Sanderson said the company expected to recover as much as 15 percent of the oil in the Weald area, which he said would translate to the 2030 equivalent of 30 percent of the nation's oil demand.