Lowering the Steam-to-Oil Ratio (SOR)
Creating the steam required for SAGD operations is a major source of capital and operating costs, energy consumption and water usage. The oil sands industry and research organizations have a sustained focus on reducing the amount of steam needed to produce a unit of bitumen – the steam-to-oil-ratio or SOR. A lower SOR creates across-the-board advantages:
- Reduced capital and operating costs;
- Higher productivity on a capital-per-daily-flowing-barrel basis;
- Smaller surface facilities and physical footprint;
- Reduced water use;
- Reduced energy consumption; and
- Lower air emissions, lower greenhouse gases.
The Clearwater Project is designed to achieve a much lower SOR than the typical 3:1 ratio of conventional SAGD operations. The primary method is low-pressure operation complemented by solvent co-injection, designed to reduce the SOR from an estimated 3.2:1 using conventional SAGD to as little as 1.8:1 in the Clearwater reservoir. This would be an improvement of nearly 45 percent.
Other SAGD operations employing solvents have demonstrated material reductions to the SOR.
Over the longer term, AOS may also employ electrical heating to further reduce the SOR to as little as 1.2:1. Research into this process is at an early stage and the Clearwater Project’s viability does not depend on the success of this technology.
If the AOS recovery model at Clearwater proves successful, it will exhibit among the lowest SORs in the oil sands sector, which will maximize efficiencies and project economics while minimizing environmental impact.