OIL SANDS AND ORIMULSION
Edition 1 – 2003
From the NRG Expert Historical Energy Data Series
Three have been some objections to Orimulsion from environmental lobbies but in reality the fuel is no more environmentally dangerous than other fossil fuels, and better than some. Emissions of carbon dioxide per unit of electricity generated from burning Orimulsion are similar to those from heavy fuel oil and less than those from coal, although greater than for combined cycle gas plant. Due to Orimulsion’s water content and hence lower calorific value, around 42% more Orimulsion needs to be burned to generate the same amount of electricity. Consequently, without SO2 abatement, more SO2 would be generated per unit of electricity with Orimulsion than with heavy fuel oil. The emission of SO2 may, however, be substantially abated through the fitting of widely used FGD ( fuel gas desulphurisation) equipment, which ‘scrubs’ over 90% of the sulphur dioxide out of the fuel gases before they are released to the atmosphere. Orimulsion is suitable for use in low NOX burners and with other NOX reduction technologies. Power stations worldwide, which are currently burning Orimulsion, are fitted with electrostatic precipitators in addition to FGD. Their emissions of particulates are within the limits required of new plant in the UK and EU countries.
Orimulsion is transported from Venezuela in double-hulled tankers. Should a spill occur at sea, Orimulsion mixes readily with the body of water because it already contains emulsifying agents. It does not tend to float on the surface like a blanket and does not have the suffocating effect of an oil slick. In terms of its long-term fate and degradation, spills of Orimulsion pose similar environmental risks to those of heavy fuel oil.
There was much experimentation with oil sands technology in the first half of the 20th century but it was not until the 1950’s and early 1960’s that commercial development became viable. Production depends on the depth of the deposits. Where the bitumen is buried deep enough to prevent severe heat loss, the bitumen may be produced from wells by the use of steam injection. The development of horizontal well drilling has led to a significant advancement in bitumen recovery, the SAGD process, through use of a higher horizontal steam injection well and a lower horizontal well to receive the mobilised oil by gravity drainage. The Government of Alberta’s oil sands development policy was announced in 1962 and the Great Canadian Oil Sands Project (GCOS) was conceived and approved.
Exploitation of the Alberta natural bitumen is well advanced. Taking into account all operations, total output from Canadian oil sands in 1999 was 323,000 b/d of synthetic crude and 244,000 b/d of crude bitumen from the in-situ plants; together, these represented 22% of Canada’s total production of crude oil and NGL.