Environmental analysis from Implementation of In Situ Combustion based Technology on Athabasca Bitumen Reservoirs

Abstract

The in situ recover method is becoming more and more attractive for oil companies. One of the technologies that are currently experiencing the most growth is Steam Assisted Gravity Drainage (SAGD). An emerging technology In Situ Combustion has a strong potential to improve oil sands operation, since it requires less water and it is based on air injection into the reservoir. In order to quantify environmental consequences associated with switching from one of the technology to another, several simplified LCA studies with cradle-to-industrial gate basis were conducted.Based on the daily production of 40 000 barrels of bitumen, the total impact generated by the SAGD technology is 4800 tonnes of CO2 equivalents, where the steam generation and other facility units contribute 65 % of the total impact. Diluent production and natural gas contribute respectively 15% and 11%. The import of electricity generates 8% of the total impact to climate change. The total impact generated by the ISC technology at the production rate of 40 000 barrels per day is 4298 tonnes of CO2 , where the direct emissions ( connected to the processes on-site) contribute 72% of the total impact to climate change. Diluent s production contributes 15% of the total impact and production of compressed air by air compressor unit is responsible for 10% of the total impact to the climate change impact categories. Also at the comparison stage, the findings showed that though the oil recovery for ISC is 70% and higher than for SAGD 53%, there are some environmental impacts potentials associated with the production of air compressor unit, for example, the impacts per daily production to human toxicity, freshwater ecotoxicity for SAGD are 370 tonnes of 1.4-DB eq., and 9.8 tonnes of 1.4-DB eq. respectively; while for ISC the impacts associated with daily production to the same categories are 2280 tonnes of 1.4- DB eq. and 31.5 tonnes of 1.4-DB eq. The improvement in the electricity production for SAGD processes by on-site generation resulted in emission reduction, but the total contribution to climate change was still higher, than for ISC. Though, the discrepancy narrowed by 3%.