Gravity Drainage (SAGD)
SAGD is a key
technology that will be how most in-situ production is done in the years to
come. Pairs of horizontal wells are drilled
one above the other into the oil sands formation, and steam is injected into the
upper well. The steam heats the oil sand and it softens and drains into the
lower well, where it naturally flows to the surface.
steam stimulation works best in formations like those near Cold Lake with good
horizontal permeability, SAGD works better in deposits with good vertical
permeability, like the Athabasca deposit near Fort McMurray.
steam stimulation (CSS) and SAGD use enormous amounts of natural gas to make the
steam necessary to extract the bitumen. So in essence, developers are using
energy to make energy.