It’s all a bit embarrassin’. Haroldo Lima, a director of Brazil’s National Petroleum Agency, gossiped about a stupendous oil find offshore of Rio de Janeiro. He suggested it was some five times the size of Tupi, an eight billion barrel monster that was confirmed in November as the discovery of the decade. His indiscretion ignited the share price of Petrobras, the partially privatised state oil company, and BG Group, its lucky British partner.

Unfortunately, Mr Lima set off his firecracker before the carnival had even been confirmed. The evaluation of the find is incomplete and some are suggesting that it is all a fuss over nothing.

Were it true, it would catapult Petrobras and with it Brazil into the superleague of oil exporters, rivalling the Gulf states and dwarfing oil majors such as ExxonMobil and Shell. Even without the new find, Brazil will soon be a big oil exporter, with Tupi alone delivering one million barrels per day within five to seven years.

Such windfalls are not without their problems, of course. They can bring an embarrassment of riches that risk stoking corruption.

But it will certainly change Brazil’s status on the world stage. Its economic muscle in agribusiness is causing it to lock horns with Washington in frequent trade disputes and oil wealth will increase Brazil’s clout further.

Washington is desperate for friendly energy supplies. Will Brazil join Opec? Probably not. But you can imagine President da Silva’s smile as he responds to the anxious senators on Capitol Hill.

Closer to home, another embarrassment of riches may be brewing. For BG Group, its partnership with Petrobras has, until now, been the icing on a rich cake baked by Frank Chapman, the former Shell executive who has transformed the international arm of British Gas into what he likes to call the first integrated gas major. With upstream gas, a fleet of liquefied natural gas ships and terminals in Europe and America, BG Group has built a commanding position in a rapidly expanding trade.

That raises the question of what it should do with Tupi, not to mention the potential new prize. Is BG a bubbling gas company with a bit of oil attached, or is the oil about to swamp the gas?

Looking forlorn on the sidelines is Shell, which for many years has coveted BG, occasionally dusting off a very old takeover plan before balking at the price. Rather embarrassing now.

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive