Bottom of the Barrel

Going to new depths in the search for old oil

At the rate we’re going, the Department of Energy expects conventional oil production to peak in 2050. But the end of oil won’t necessarily usher in a greener future. Locked in sand, rock, natural gas, and coal are enough hydrocarbons to supply the world’s oil refineries with so-called unconventional crude through most of the 21st century.

conventional oil
How it’s produced: Drilling in the ground
Where it’s found: Middle East, Russia, United States, elsewhere
Average production cost per barrel: $9
Greenhouse gas (ghg) emissions from production: 5 grams of carbon equivalent per megajoule
Potential output: 2,162 billion barrels
Dirty secret: 77% is controlled by state-run companies, so Big Oil is turning to unconventional sources to survive.

enhanced oil recovery
How it’s produced: CO2 is injected into old oil wells to squeeze out the last 30 to 60%.
Where it’s found: United States, Middle East
Average production cost per barrel: $16
ghg emissions from production: 67% more than conventional oil
Potential output: 1,011 billion barrels
Dirty secret: Could have an environmental upside if oil companies figure out how to sequester CO2 in old wells—and guarantee it won’t leak out again.

tar sands and heavy oil
How it’s produced: Ore is extracted and processed into synthetic crude.
Where it’s found: Canada, Venezuela
Average production cost per barrel: $23
ghg emissions from production: 151% more than conventional oil
Potential output: 1,535 billion barrels
Dirty secret: Each barrel of oil produced leaves behind two of toxic waste. Refining tar sands oil produces as much as 80% more CO2 than conventional refining.

gas-to-liquid synfuel
How it’s produced: Natural gas is mixed with oxygen, purified, and processed into transportation fuels.
Where it’s found: Russia, Iran, Qatar
Average production cost per barrel: $26
ghg emissions from production: 66% more than conventional oil
Potential output: 3,597 billion barrels
Dirty secret: South Africa perfected the technology in response to apartheid-era trade embargoes.

liquefied coal
How it’s produced: Coal is heated and pressurized to create a gas, which is converted to fuel using the gas-to-liquid technique.
Where it’s found: The largest coal reserves are in the United States, Russia, China, India, and South Africa.
Average production cost per barrel: $35
ghg emissions from production: 393% more than conventional oil
Potential output: 8,892 billion barrels
Dirty secret: Mercury is a byproduct. Last year, Senator Barack Obama cosponsored a bill that would have provided the industry with federal loans for as much as $20 million. Enviros accused him of pandering to Illinois coal interests.

oil shale
How it’s produced: Oil-containing rock is mined, crushed, cooked, and injected with hydrogen.
Where it’s found: Colorado, Utah, Wyoming
Average production cost per barrel: $57
ghg emissions from production: 530% more than conventional oil
Potential output: 1,451 billion barrels
Dirty secret: In 2007, former secretary of the interior Gale Norton joined Shell’s oil shale team.


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