Survey of Energy Resources 2007
Oil Shale Country Notes
The oil shale resource base is one of the largest in the world and was first exploited in 1884 in the State of Bahia. In 1935 shale oil was produced at a small plant in São Mateus do Sul in the State of Paraná and in 1950, following government support, a plant capable of producing 10 000 b/d shale oil was proposed for Tremembé, São Paulo.
Following the formation of Petrobras in 1953, the company developed the Petrosix process for shale transformation. Operations are concentrated on the reservoir of São Mateus do Sul, where the ore is found in two layers: the upper layer of shale (6.4 m thick), with an oil content of 6.4%, and the lower 3.2 m layer with an oil content of 9.1%. The company brought a pilot plant (8 inch internal diameter retort) into operation in 1982, its purpose being for oil shale characterisation, retorting tests and developing data for economic evaluation of new commercial plants. A 6 ft (internal diameter) retort demonstration plant followed in 1984 and was used for the optimisation of the Petrosix technology.
A 2 200 (nominal) tonnes per day, 18 ft (internal diameter) semi-works retort (the Iratí Profile Plant), originally brought on line in 1972, began operating on a limited commercial scale in 1981 and a further commercial plant - the 36 ft (internal diameter) Industrial Module retort - was brought into service in December 1991. Together the two commercial plants have a process capacity of some 7 800 tonnes of bituminous shale daily. The retort process (Petrosix) where the shale undergoes pyrolysis yields a nominal daily output of 3 870 barrels of shale oil, 120 tonnes of fuel gas, 45 tonnes of liquefied shale gas and 75 tonnes of sulphur. Actual daily output in 2005 was 3 040 barrels of shale oil, 80 tonnes of fuel gas, 31 tonnes of liquefied shale gas and 49 tonnes of sulphur.
The Ministry of Mines and Energy quotes end-1999 shale oil reserves as 445.1 million m3 measured/indicated/inventoried and 9 402 million m3 inferred/estimated, with shale gas reserves as 111 billion m3 measured/indicated/ inventoried and 2 353 billion m3 inferred/ estimated.