Why Use Solvent?
Solvents, including liquid hydrocarbons such as diluent, are increasingly being incorporated into SAGD bitumen projects. Adding solvent achieves a number of benefits, including:
- Higher well production rates;
- Increased ultimate recovery of the bitumen-in-place; and
- Reduced steam per unit of bitumen produced, or SOR, which in turn means:
- Lower energy consumption for steam production;
- Smaller surface facilities, which in turn reduce the amount of disturbed land, and the capital expenditures required to achieve a given level of bitumen recovery;
- Reduced air emissions, including of greenhouse gases; and
- Lower volume of water consumption for steam production.
Established SAGD operators are reporting that adding solvent to the SAGD process can reduce the SOR by at least 40 percent. These strong benefits suggest a compelling technical, economic and environmental case for using diluent in SAGD-based bitumen recovery. The AOS steam-diluent co-injection model is described here.