Brazil’s Petrobras increased reserves estimated to be contained in its pre-salt offshore fields by 43% last year compared with 2012, the operator revealed.

More than a quarter of the country’s proven reserves are now attributed to pre-salt fields, which extend from the south of Espirito Santo state to the state of Santa Catarina.

A total of 42 wells were drilled in pre-salt formations last year, Petrobras said, and with what it described as an “outstanding performance” from its Campos and Santos Basin production facilities, reserves grew by 43%.

On 14 January Petrobras said it set a new daily production record when pre-salt fields output rose to more than 390,000 b/d, beating the previous record of 371,000 b/d set on 24 December last year.