Petrobras started oil shale processing activities in 1953 by developing Petrosix technology for extracting oil from oil shale of the Irati formation. A  inside diameter semi-works retort (the Irati Profile Plant) with capacity of 2,400 tons per day, was brought on line in 1972, and began limited commercial operation in 1980. The first retort that used current Petrosix technology was a  internal diameter retort pilot plant started in 1982.
Petrobras initiated oil shale processing activities in 1953 by employing Petrosix technology to extract oil from Irati formation oil shale. A semi-works retort with a diameter of 2,400 tons per day was operational in 1972 and began limited commercial operation in 1980. The first pilot plant using current Petrosix technology started in 1982.