Underground is a great place to store greenhouse gas

“It’s one thing to say that underground is a great place to store carbon dioxide, but it’s another thing to be able to prove it as we have done,” said Rostron, from the U of A’s Faculty of Science and a co-author on a paper appearing today in GSA Today, a journal published by the Geological Society of America. “We have been able to show that you can safely capture carbon dioxide that would otherwise go back into the atmosphere, and put it back into the ground. It’s very exciting work.”

Carbon dioxide is a naturally occurring greenhouse gas in the atmosphere. Its concentrations have increased as a result of human activity, such as burning coal, oil, natural gas and organic matter. CO2 emissions have been linked to global warming, and there has been a worldwide effort to reduce those emissions and their effects on the planet. The efforts in the Weyburn project are one way for Canada to meet targets under the Kyoto Protocol, for example.

Carbon dioxide sequestration is being evaluated internationally as a viable means of long-term storage. Rostron is part of the project started in 2000 to investigate the technical and economic feasibility of storing the gas in a partially depleted oil reservoir in Saskatchewan. The researchers are working with Encana Corporation on their 30-year commercial carbon dioxide enhanced oil recovery operation, which is designed to recover an incremental 130 million barrels of oil from the Weyburn field in Saskatchewan.

The gas comes from the United States, where it is compressed and sent through a pipeline to the Weyburn field. There, Encana injects it into the reservoir and the results are observed by the project scientists and stakeholders--including regulatory agencies and government officials. More than 1.9 billion cubic metres have been injected so far.

Not only has the project demonstrated one way for the industry to economically reduce carbon dioxide emissions that would have otherwise gone into the atmosphere, but it allows the oil industry to pump carbon dioxide into its wells and produce extra oil, said Rostron. The work also demonstrates that geological sequestration can be successful, enabling wider application in other parts of the country and the world, he added.

“The oil companies have seen incremental production close to what they predicted and from the scientists’ point-of-view, we’ve been able to see a response to our techniques and been able to monitor it very, very closely,” said Rostron, the hydrogeology co-ordinator on the project. “Everything we’ve done has shown us this is a good place to store carbon dioxide.

“Countries around the world are spending millions to investigate this same technique and we’ve been able to do it with success.”

Source: http://www.ualberta.ca/