Pay Dirt: How to Turn Tar Sands into Oil [Slide Show]

More and more petroleum is flowing from Alberta's vast oil sands deposits

FAST DRYING: New methods to dry the aftermath of mining and extraction could reduce the need for the vast tailings ponds. Both Suncor and Syncrude are presently testing alternatives—mixing in polymers to help clay settle out or employing centrifuges to spin out the water—to speed up the reclamation process... © David Biello
AFTER THE TAILINGS: The vast tailings lakes can also be reclaimed. Pond 1, shown earlier in 2002, closed in 2007 and has now been remolded into swales and hummocks, including a natural wetland and 60 different species of tree seedlings and shrubs planted atop its 220 hectares... Courtesy of Suncor
GATEWAY HILL: After the mining is done, the oil sands industry is required to reclaim the landscape. The first such reclamation—and the only one to complete the laborious process of certification and return the land to provincial ownership—is known as Gateway Hill... © David Biello
FINDING OIL: To determine the best location for an oil sands operation, exploration teams conduct seismic surveys, cutting parallel paths through the boreal forest and carving out square clearings for the explosives... © David Biello
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DISTURBED LAND: An in situ installation disturbs far less of the boreal forest than the swathes of land chewed up by strip mining, as evidenced by this overflight picture of the Christina Lake in situ project, but such undertakings produce even more greenhouse gas emissions than mining operations... Courtesy of Cenovus
STEAM FLOOD: The vast majority of the oil sands cannot be recovered by mining because the deposits are simply too deep. Instead, 350-degree C hot, pressurized steam is pumped at least 200 meters underground to melt out the hard bitumen in place—hence the name for the procedure: in situ recovery... © David Biello
TAILINGS LAKE: Vast man-made sand berms that rise as high as the bluffs carved by the Athabasca River hold back lakes-worth of tailings—the water, residual oil, clays and, primarily, sand left over after mining and separation... Courtesy of Suncor
SCALE: The oil sands mining operations of Suncor alone produce nearly 400,000 barrels of upgraded oil per day—and a copious quantity of coproducts. Whereas Suncor trucks its daily output of 1,200 to 1,500 metric tons of slurried sulfur away for use in applications like fruit drying, Syncrude has decided to stockpile, resulting in the large yellow LEGO-like blocks visible here that are the size of the base of a pyramid... © David Biello
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COPRODUCTS: In addition to coke and crude oil, the upgrading process produces a variety of coproducts, such as the bright yellow elemental sulfur in the fifth bottle from the left. It's production requires copious catalysts, as seen in the bottle second from right... © David Biello
CRACKING BITUMEN: At the core of the upgrading plant looms the 88-meter-tall coking tower, where bitumen is cracked into shorter-chain hydrocarbons, including diesel and naphtha, used to dilute some bitumen and ship it via pipeline instead of upgrading it on-site... Courtesy of Suncor
USABLE OIL: To turn thick bitumen into saleable petroleum products, oil sands operators rely on upgraders—mini-refineries to transform bitumen into crude oil using heat, pressure and chemistry like the Syncrude Canada plant pictured here... © David Biello
BITUMEN: With the sand and water removed, what remains is bitumen—a thick, tarry form of petroleum that will not run, although it bubbles as natural gas escapes. Even at projected production rates of more than five million barrels per day, there are enough oil sands to last for centuries... © David Biello
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INDUSTRIAL SEPARATION: At a typical mining operation large separation cells—giant funnels that mix 80-degree Celsius hot water and chemicals to reduce acidity with the oil sands—produce a bitumen froth that overflows into catchment basins... Courtesy of Suncor
OIL SEPARATION: Add hot water to tar sands and, with a little mixing, the oil, water and sand begin to separate. "You take the ore, mix it up with warm water, and the bitumen floats to the top and you skim it off," explains Murray Gray, scientific director of the Center for Oil Sands Innovation at the University of Alberta... © David Biello
MINING GIANTS: In decades past spinning scoop shovels connected to conveyor belts were used to mine the ore, and a couple relics rise above the wintry landscape like ancient dinosaurs frozen in place... © David Biello
ABRASIVE SAND: Under a microscope, the sand part of oil sands look like jagged, clear rock-daggers, perfect for steadily wearing down the teeth of the crushers used to resize big blocks of tar sand into 30-centimeter chunks that then are transferred by conveyor belt for further processing... © David Biello
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HEAVY HAULER: The world's largest trucks are employed to cart 400 tons worth of oil sands from the mine face to the processing plant, where the oil sands are ground down to size. The Caterpillar 797 weighs more than 600 tonnes and is nearly eight meters tall, 15 meters long and 10 meters wide... Courtesy of Suncor
OIL MINING: Electric-powered, 1,500-tonne scoopers carve out chunks of the hillsides full of oil sands and dump them into trucks guided to the site by global positioning satellite (GPS) software. Three or four big bites are enough for a full load, and the scoopers scoop until they hit the layer of limestone beneath the tar sand deposit... Courtesy of Suncor
TAR SANDS: Water and a film of bitumen surrounds each grain of sand, making Alberta's oil sands the easiest to work with to free oil. A typical "ore" will be 73 percent sand, 12 percent bitumen, 10 percent clay and 5 percent water... © David Biello

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