What is the name of the oil-recovery method that injects steam to drain bitumen from deep Canadian oil sands?

Steam-assisted gravity drainage is the oil-recovery method that injects steam to drain bitumen from deep Canadian oil sands.

Usually abbreviated SAGD, the method uses two horizontal wells drilled one above the other. Steam is injected into the upper well, heating the bitumen and reducing its viscosity. The warmed bitumen then flows downward under gravity into the lower production well, where it is pumped to the surface.

SAGD made it possible to develop deposits too deep for conventional surface mining. It is widely used in Alberta, where much of the oil sands resource lies underground. The process requires water treatment, steam generation, and substantial energy, so operators monitor its water and greenhouse-gas intensity.

SAGD differs from hydraulic fracturing, which creates fractures to improve flow through tight rock. It also differs from open-pit mining, which removes shallow oil-sands material from the surface.