Angola has 13 billion barrels of proven oil reserves, a top oil official from the African nation said today.

The total is nearly four billion barrels more than an OPEC estimate for late 2012.

The Organization of the Petroleum Exporting Countries, whose estimates on the oil reserves of its members often differ from the countries’ own numbers, has said Angola had 9.1 billion barrels of oil reserves at the end of last year.

Angola’s vice minister for petroleum, Anibal Octavio Teixeira da Silva, told the World Energy Congress in South Korea today that the country would continue producing 1.7 million barrels of oil per day through the end of 2013. It expects to reach 2 million bpd by 2015.