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 commenced oil shale processing activities in 1953 with the development of Petrosix technology for extracting oil from Irati formation oil shale. A semi-works retort with a capacity of 2,400 tons per day was brought online in 1972 and began limited commercial operation in 1980. The first pilot plant utilizing current Petrosix technology started operations in 1982.