The squat shed in the middle of a Prairie field would be unremarkable if not for the fact that it is surrounded chain-link fence, barbed wire and danger signs warning of CO{-2} under immense pressure.
Here, at the intersection of two pipelines about 70 kilometres north of the border, oil giant EnCana Corp. takes delivery of a stream of pure carbon dioxide from an American supplier -- then injects it more than 1,500 metres underground to stimulate the production of crude.
This enhanced oil-recovery project is paying off. Production has jumped to 30,000 from 10,000 barrels a day and has extended the reservoir's life by decades.
But it's not oil-field economics that has attracted scientists, energy companies, government officials and media from around the world to southern Saskatchewan.
The Weyburn site is billed as the world's largest demonstration of a promising technique called geological sequestration -- a method of preventing greenhouse gases such as carbon dioxide from entering the atmosphere and wreaking havoc with the environment.
Typically, coal-fired power plants, refineries and other industrial processes that use boilers burn fuel in the air. This process generates an emissions stream including carbon dioxide, nitrous oxide and other gases.
In carbon capture and storage, the CO{-2} is first separated from the emissions stream. This can be done by burning the fuel in oxygen rather than air, or by treating the emissions with a CO{-2}-absorbent solvent.
This pure greenhouse gas is then diverted through compressors that pressurize it and reduce its volume, allowing it to be shipped through the kind of pipeline system that normally transports natural gas.
When the CO{-2} arrives at an appropriate burying spot -- an old oil reservoir, perhaps, or a deep structure of porous rock containing brackish water -- it is pumped underground and stored.
This system of sequestering CO{-2} is seen by some experts as the ultimate solution to global warming -- a way for society to use fossil fuels without the harmful effects. The only drawback: the costs of burying greenhouse gases deep enough that they stay underground.
In the U.S., oil companies have been injecting carbon dioxide to boost crude production for years. Until recently, though, no one bothered to study whether the CO{-2} would remain trapped.
Now, prompted by global-warming concerns, scientists are investigating what happens to the gas after it is pumped underground -- and Weyburn is one of the primary labs.
EnCana buys its CO{-2} from the Dakota Gasification Company, a North Dakota plant that draws synthetic natural gas from coal and produces carbon dioxide as a byproduct. DGC then compresses the carbon dioxide and pipes it 325 kilometres north.
The Calgary-based oil company injects about 1.5 million tonnes of this CO{-2} a year and expects to use a total of 30 million tonnes over the life of the project -- the equivalent (rather ironically) of taking 6.8 million cars off the road for one year.
"We call it 'CO{-2} - rest in peace' because we show how it is entombed in the reservoir," says Twila Walkeden, an EnCana spokeswoman who typically deals with local farmers and town officials, but is currently playing tour guide for a growing number of scientists.
Scientists from the Regina-based Petroleum Technology Research Centre, for example, have studied EnCana's experience with carbon-dioxide injection and concluded that the CO{-2} sequestered in Weyburnwill be trapped underground for at least 5,000 years.
Financed by federal and provincial governments, the PTRC was established at the University of Regina to explore oil-field engineering. The EnCana project satisfied two of the centre's goals: to improve production from declining oil fields and to reduce the environmental impact of the industry.
But the fate of CO{-2} after it has been injected remains a key question for hydrologists and geologists. Will it migrate to the surface and leak out over time? Will it contaminate local groundwater or deep freshwater aquifers?
