Observing buried carbon dioxide

A project proves that millions of tons of the sequestered gas can be safely monitored.

By David Talbot

Scientists say that fighting climate change will  require pumping billions of tons of carbon dioxide underground. But will it be possible to monitor such large-scale sequestration to make sure it's not leaking? Evaluations at a remote CO₂-burial site in Saskatchewan suggest that the answer is yes.

"We have demonstrated fairly convincingly that you can monitor the CO₂ underneath the surface using seismic technologies," says Don White, a research scientist at the Geological Survey of Canada, who presented the latest analyses of the site in Weyburn, Saskatchewan, at a conference in Washington, DC, this week. "The results have been positive so far. If we went to regulatory hearings and were asked, 'How do you know it's safe?' we'd say, 'We've demonstrated that it works and that we can monitor it.'"

Weyburn is one of the leading facilities in the world for studying underground CO₂ storage. Located just north of North Dakota, it consists of two old oil fields that use carbon dioxide pumped underground to increase oil production. The site also accepts carbon dioxide piped from the Great Plains Synfuels Plant.

To date, Weyburn has buried 11 million tons of CO₂, most recently at a rate of three million tons per year. To put this in perspective: an intermediate-size coal plant emits about two million tons of carbon dioxide each year--and there are about 600 coal power plants in the United States. So the annual amount that Weyburn accepts is equivalent to roughly one-quarter of one percent of the CO₂ emitted by U.S. coal power plants.

Observing Buried Carbon Dioxide
Thu, 20 Nov 2008 05:00:00 GMT

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