A group of three oil companies led by the American company Chevron have announced the discovery of a new oil field in the Gulf of Mexico, about 270 miles south of New Orleans. The new field may have between 3 and 15 billion barrels of oil. The resulting boost in Chevron's stock helped push up the New York Stock Exchange Tuesday, although the field will not be in production for several years. The test reached almost four miles below the ocean's surface, making it the deepest test in the Gulf of Mexico. The other two companies that took part in the test were Norway's Statoil and the American company Devon Energy; analysts saw it as very good news for Devon.