The Resource ► Alberta's oil sands contain the biggest known reserve of oil in the world. An estimated 1.7 to 2.5 trillion barrels of oil are trapped in a complex mixture of sand, water and clay. Bitumen is a heavy, carbon rich, extremely viscous oil. The percentage of bitumen in oil sand can range from 1% -20%.
Mining Production ► Roughly 500 km2 of the 140,000 km2 oil sands deposit in Northern Alberta is currently undergoing surface mining activity. Oil sands within 75 m of the surface are mined using electric and hydraulic shovels with a capacity of 45 m3 and trucks that can carry up to 400 tons of ore that take three passes to fill.
In Situ Production ► In situ recovery is used for bitumen deposits buried too deeply - more than 75 m - for mining to be practical. ► Most in situ bitumen and heavy oil production comes from deposits buried more than 350-600 m below the surface. ► Steam, solvents or thermal energy make the bitumen flow to the point that it can be pumped by a well to the surface. ► Cyclic steam stimulation (CSS) and steam-assisted gravity drainage (SAGD) are effective in situ recovery methods. ► No tailings ponds are required for in situ methods of recovery. Sand remains in the ground; only bitumen is removed.
Refining the Bitumen ► Step 1: distillation. Separates various compounds by physical properties. ► Step 2: coking, hydro-conversion, solvent deasphalting. Improves hydrogen to carbon ratio. ► Step 3: hydrotreating. Removes contaminants such as sulphur.
Environmental Issues ► Non-renewable Resource ► Global Warming (CO 2 ) ► Water Pollution (Heavy Metals) ► Water Use (2-4L water needed to make 1L oil) ► Toxic “Tailings” Ponds (waste left over) ► Air Pollution (Hydrogen sulfide gas released from crude) ► Deforestation (clearing trees) ► Habitat Destruction (removing top soil) Approximately 2 tonnes of oil sands are needed to produce 1 barrel of oil