British energy exploration company UK Oil & Gas Investments Plc (UKOG) announced Thursday the discovery of up to 100 billion barrels of oil onshore in southern England. Last year, the firm had drilled a well at Horse Hill in the Weald Basin, and an analysis conducted by US-based Nutech Ltd on behalf of UKOG estimates that the local area has a total oil in place (OIP) of 158 million barrels per sq