The 2006 discovery of the Tupi oilfield (now known as Lula) off the coast of Rio de Janeiro transformed Brazil's fortunes and was followed by a series of additional pre-salt discoveries, securing the country's future as a global energy power. The oil is contained in reservoirs below a layer of salt 5,000 to 7,000 metres below the surface of the ocean. Preliminary tests in four areas by state-controlled oil company Petróleo Brasileiro S.A. (Petrobras) have shown recoverable volumes of between 10