Just as in mining, it is difficult to draw direct comparisons on water usage among in situ oils sands operators as each project is at a different stage of maturity and uses different processes in reservoirs with varied properties - all factors which may affect their water usage. For example:

-       Once a pad is operational, the water used in a Steam Assisted Gravity Drainage (SAGD) extraction is injected and produced continuously whereas the steam used in Cyclic Steam Stimulation (CSS) is injected, then allowed to “soak” before the water/ bitumen is produced. Consequently on a pad basis the water use is cyclical in CSS operations, but not in SAGD extractions.

-       When a SAGD in-situ project first starts operating there is a period of steaming to heat and pressurize the reservoir with no return bitumen production flows.

-       As a SAGD well pad matures, the ratio of water to bitumen being produced slowly rises until an economic cut-off is reached. Many operators prefer to balance aging well pads with new ones to make the water requirements more consistent over time.  

-       Operating reservoirs at higher pressures to increase the rate of production, but also causes more water loss and requires significantly more water than a low pressure operation.