This diagram has two panels. The first panel shows oil is produced from Canada’s Oil Sands using horizontal wells in what is called steam-assisted gravity drainage (or SAGD). One horizontal well injects steam into an underground oil sands reservoir, creating a “steam chamber”. The heated bitumen in the steam chamber then flows down into a second, underlying well, where the bitumen is then pumped to the surface. The second panel shows how oil and gas are produced using a vertical well and a hydraulically fractured horizontal well. The vertical well taps into a porous sandstone. The horizontal well taps into a source rock or porous, tight formation and is surrounded by a halo of fractures.