The Brazil state-led company has spent $1.6 billion on the Proef programme since its inception in May 2012 to reverse production declines at ageing fields eating away at broader output figures.
The effort has increased "operational efficiency" at older platforms in the Campos basin sector of the programme to 75.4% from 71.7% at its inception.
The Rio-UO unit, which oversees newer platforms in the same basin, saw its efficiency grow to 92.4%
