The oil in the oil sands comes in the form of a hard, tar-like substance called bitumen. Steam is used to warm the bitumen enough to flow for extraction. The addition of a diluted solvent makes it much more effective. In fact, Solvent-Assisted Steam-Assisted Gravity Drainage (SA-SAGD) can help make oil extraction more energy efficient, use less water and reduce greenhouse gas emissions.
Developed in the 1970s, Steam-Assisted Gravity Drainage (SAGD) is the method most commonly used to extract bitumen from an oil sands deposit that is too deep to mine. The technique involves drilling two horizontal wells into a reservoir, one on top of the other. Steam is injected through the top well, melting the bitumen and causing it to drain to the bottom of the reservoir, where it’s pumped to the surface through the lower well. Recent research has focused on adding a solvent to the steam (SA-SAGD) to reduce water use, energy use, and emissions. The results so far indicate that SA-SAGD can reduce water use by up to 25 per cent, and reduce greenhouse gas emissions up to 25 per cent.
What does SA-SAGD stand for?
SA-SAGD is an abbreviation for solvent-assisted steam-assisted gravity drainage. It’s a process where light oil and steam are added to an oil sands reservoir in order to remove heavy oil.