A string of oil companies have struck oil near Gatwick Airport in southern England.The companies, including Stellar Resources, Solo Oil, Regency Mines, UK Oil & Gas Investments, Alba Mineral Resources and Doriemus, are in a consortium that has found an oil accumulation in the Horse Hill-1 well on the northern side of the Weald Basin near the East Sussex airport.A preliminary most likely estimate of 3.1 million barrels (mmbbls) of oil has been calculated within the Upper Jurassic Portland Sandstone, with a further potential 16.8 mmbbls of oil in a separate lower sand in the Portland interval located in an untested fault block to the south.The well is being deepened to a level where an additional target, believed to have potential for gas, is expected to be reached in the next two weeks.Stellar and the others own stakes in Horse Hill Development Ltd (HHDL), a special purpose company which owns a 65% participating interest in licences in the Weald Basin. Magellan Petroleum Corporation owns the other 35%.Stellar's chairman Donald Strang said: ""We are delighted with the results so far from this well. The presence of a larger, unappraised, Portland feature creates considerable further upside. We are now looking forward to drilling the Triassic, which is a new and untested exploration target in the area and which, if successful, may contain appreciable volumes of gas."