Total reserves: 1 to 2 trillion BOE
Other unconventional resources may, despite having many shortcomings, become somewhat more attractive as new extraction methods come online. One of these is “heavy oil,” which ranges from the molasses-like crude in Venezuela to the bituminous oil sands of Alberta. For decades, oil traders saw heavy oil as inferior to light crude, which is easier to extract and whose smaller-chain molecules are more readily refined. Heavy oil’s bigger molecules, in contrast, were suited mainly to low-profit products, such as ship fuel or asphalt. But new refining techniques are making heavy oil more renderable into gasoline, and new extraction methods are making it easier to get out of the ground.
At a heavy-oil field outside Bakersfield, California, for instance, Chevron deploys computer-guided steam injection to thin the oil sufficiently to pump out. Even more promising are oil-sands operations in Alberta, where companies are now separating the brittle bitumen from sand and clay and cooking it into synthetic crude. At a conversion rate of one barrel for every two tons of sand, Alberta’s oil sands alone may contain up to 315 billion barrels of crude. As refining costs have dropped, output has reached 1.5 mbd and could more than quadruple, to 6.3 mbd, by 2035.
That said, heavy-oil production also has plenty of external costs. As with the kerogen in shale, the bitumen is processed either in-ground or by strip-mining. Both processes consume up to 4.5 barrels of water for every barrel of oil they produce and yield an unimpressive EROEI of about 7:1. And because heavy oils are carbon-rich, the CO2 footprint of crude from bitumen is up to 20 percent higher than that of conventional crude—not as bad as coal, but not exactly friendly to the environment either. Carbon-capture and -sequester techniques can only keep so much of that CO2 out of the atmosphere. Oil-sands operations are sprawling, and as a result, very little of the total CO2 emissions can be captured (one study suggests we might trap just 40 percent by 2030).
If carbon-capture techniques improve, though, heavy oil could make up a substantial share of the final two trillion barrels for a carbon penalty substantially below that of either CTL or shale oil. A further advantage (from the U.S. perspective) is that a lot of heavy oil is located in a politically stable country that’s right next door.single page
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