Tar sands fever! It's about water, sand, and oil--but this is no day at the beach.

AuthorWoynillowicz, Dan

It's well known that the United States consumes more oil per capita than any other country in the world, absorbing two-thirds of global oil production. This heavy dependence has often, and aptly, been described as an addiction; even U.S. President George W. Bush trotted out the metaphor in his 2006 State of the Union address ("America is addicted to oil").

Most of us regard addictions (to anything) as inherently unhealthy and admission of the problem as the first step toward getting clean. In this case, however, U.S. policy has simply been to seek increased oil imports from more reliable sources closer to home--in effect, to replace distant and unstable dealers with one from the neighborhood.

Specifically, Canada--already the kingpin dealer of oil to the United States. In 2005 Canada exported almost 1.5 million barrels per day to the United States, about 7 percent of U.S. daily consumption. Canada exports 66 percent of its domestic crude oil production and since 1995 the United States has received 99 percent of these exports. At first glance, it would seem that Canada wouldn't be able to boost oil production to fill the gap; production of conventional light and heavy oil in Canada was predicted to peak in 2006 and then rapidly decline. But that's where Canada's "unconventional" tar sands come in.


The vast bulk of Canada's tar sands is found in the province of Alberta, the country's most prolific producer of fossil fuels. The tar sands deposits underlie more than 140,000 square kilometers of relatively pristine boreal forest, an area larger than the state of Florida. It's estimated that the tar sands hold approximately 1.7 trillion barrels of crude bitumen (the technical term for the fossil fuel extracted from the tar sands). But most of this bitumen will never be recovered and only a fraction, 174 billion barrels, is estimated to be recoverable using today's technology and under current and anticipated economic conditions.

When the U.S. Department of Energy formally acknowledged these reserves in 2003, it vaulted Canada's oil reserves from 21st to 2nd in the world, behind only Saudi Arabia. It's little wonder then that the U.S. Energy Policy Development Group has described the tar sands as "a pillar of sustained North American energy and economic security." Canada's so-called "black gold" has come to be regarded as an abundant, secure, and affordable source of crude oil. But development of this unconventional fossil fuel comes with unconventional risks and consequences. Everything about the tar sands is big, most significantly its global warming and environmental implications--leading some to now describe the tar sands as "Canada's dirty secret."

Producing oil from the tar sands is scraping the bottom of the oil barrel. Tar sands consist of a mixture of 85 percent sand, clay, and silt; 5 percent water; and 10 percent crude bitumen, the tar-like substance that can be converted to oil. Bitumen doesn't flow like crude oil, and getting it out of the tar sands is a messy job. The current technology, which has evolved relatively little since it was first developed in the early 20th century, is a hot-water-based separation process that requires huge quantities of water and energy (see diagram). Imagine mixing a bucket of roofing tar into a child's sandbox. Then boil some water, pour it into the sandbox, and try to wash the tar out of the sand.

Most tar sands production takes place in vast open-pit mines, some as large as 150 square kilometers and as deep as 90 meters. Before strip-mining can begin, the boreal forest must be clear-cut, rivers and streams diverted, and wetlands drained. The overburden (the soil, rocks, and clay overlying the tar sands deposit) must be stripped away and stockpiled to reach the bitumen. Four tons of material are moved to produce every barrel of bitumen. At current production rates, with just three mines operating, enough material is moved every two days to fill a 60,000-seat stadium. But only a small fraction of the bitumen deposits is close enough to the surface to be strip-mined. Over 80 percent of the established tar sands reserves are deeper and must be extracted in situ (in place) by injecting high-pressure steam into the ground to soften the bitumen so it can be pumped to the surface.

Once separated from the sand, the bitumen is still a low-grade, heavy fossil fuel that must undergo an energy-intensive process to upgrade it into a synthetic crude oil more like conventional crude, either by adding hydrogen or removing carbon. Upgrading the bitumen usually occurs before it is shipped to refineries, but sometimes raw bitumen is diluted (e.g., with naphtha) and pipelined to a refinery where it is both upgraded and refined. In the United States about three-quarters of the oil is refined...

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