According to industry officials, the Hispano-Italian consortium has identified recover-able reserves of between 2.1 and 2.4 trillion cubic feet (tcf) of gas, in addition to the seven to eight tcf announced in Spain by Hugo Chavez, the Venezuelan president, in September 2009.
The new volume means the exploration area holds recover-able resources of between 1.6bn and 1.85bn barrels of oil equivalent (boe).
This compares with total booked reserves at Repsol, for example, of about 2bn boe.
The original deposit, whose volume was assessed after drilling the Perla 1X well in shallow waters in the Gulf of Venezuela, was already the biggest such find in the country last year.
Repsol and Eni, which are in a 50-50 joint exploration venture in the area, could announce the latest upgrade as early as Monday, following tests on a second well.
Venezuela’s state-owned oil company PDVSA will take a 35 per cent stake at the development phase of the Perla fields, leaving Repsol and Eni with 32.5 per cent each.
The upward revision will provide a boost for Repsol, which has invested billions of euros in recent years – particularly in Venezuela and neighbouring Brazil – to replenish one of the thinnest reserve portfolios in the industry.
This heavy capital expenditure, coupled with falling oil prices, last year forced the company to cut its dividend to investors.
The decision almost triggered a boardroom coup against Antonio Brufau, executive chairman, by the head of Sacyr, the Spanish construction group that holds 20 per cent of Repsol.
"The Financial Times"