Guardian: Excitement about the potential of Brazil as a massive new source of oil and gas intensified yesterday after a senior energy ministry official declared that the newly found Carioca field could have 33bn barrels in place. The comments by Haroldo Lima, head of Brazil’s National Petroleum Agency, that the country was harbouring an oil find that vied with the largest in Saudi Arabia and Kuwait, sent the price of shares in BG, the UK exploration company, up 5% and helped lift the wider …