Lab Canada

Large-scale carbon dioxide storage is safe: study

Vancouver, BC – September 7, 2004 – A report released today at the international Greenhouse Gas Control Technologies Conference in Vancouver concludes that geological conditions in the Weyburn oil field in western Canada are favourable for long-term storage of carbon dioxide (CO(2)).

The four-year, multidisciplinary study was conducted by the Petroleum Technology Research Centre (PTRC) in Regina under the auspices of the International Energy Agency greenhouse gas (IEA GHG) research and development programme.

The PTRC worked on the study in close collaboration with EnCana of Calgary, Alberta, which operates the 50-year-old Weyburn field in southeastern Saskatchewan.

“The Weyburn project was the first large-scale study ever conducted in the world of the geological storage of CO(2) in a partially depleted oil field,” explains Mike Monea, executive director of the PTRC. “While there are numerous large commercial CO(2)-enhanced oil-recovery operations globally, there are none that have undertaken the depth and extent of research that we have.”

Natural Resources Canada (NRCan) is one of the 15 public- and private- sector institutions that funded the study.

Other institutions which funded the $40-million project include the United States Department of Energy, Saskatchewan Industry and Resources, Alberta Energy Research Institute and the European community. Industry participants include EnCana, BP, ChevronTexaco, Dakota Gasification Company, ENAA (Japan), Nexen, SaskPower, TransAlta and Total (France). Altogether, the project involved 24 research and consulting organizations in Canada, Europe and the United States.

During the study, researchers conducted a long-term risk assessment, completed geological and seismic studies, matched reservoir modeling against actual results, and performed repeated and frequent sampling to understand chemical reactions occurring in the reservoir.

The IEA GHG Weyburn project’s most involved industry participant was EnCana of Calgary.

The Weyburn oil field has stored an estimated five million tonnes of CO(2) over the IEA GHG project life – equivalent to taking about one million cars off the road for one year. The CO(2) is supplied through a 325-kilometre pipeline from Dakota Gasification Company’s coal-gasification plant at Beulah, North Dakota.

“The IEA GHG Weyburn project is good news for addressing climate change because it proves that you can safely store 5,000 tonnes of CO(2) per day in the ground rather than venting the greenhouse gas into the atmosphere,” says Malcolm Wilson, international energy specialist with the PTRC and one of the founders of the project.

The Weyburn field was selected for the study because detailed geological records and core samples, as well as almost 50 years of production history, were readily available. Some 380 million barrels of oil have been produced from the field since it was discovered in 1954.

The IEA GHG Weyburn study was able to:
– utilize seismic surveys to “see” the CO(2) flow within the geological formations and mix with the oil reserves;
– develop a model to predict the storage capacity of the reservoir and match results over time with the model;
– predict in a risk-assessment model that most of the CO(2) will remain in the reservoir in which it is injected, with a small amount sinking to even lower levels underground over the 5,000 years following the end of the project; and
– conclude that the CO(2) would never reach or penetrate overlying potable water zones or the atmosphere above ground level.

“Although we’re very excited with these conclusions, we believe there’s much more work to be done to determine how our techniques and systems can be applied from the Weyburn geological formation to other formations around the world, to make CO(2) storage a real option for reducing our greenhouse gas emissions worldwide,” Wilson adds.

The Greenhouse Gas Control Technologies Conference, where the report was released, is the first international gathering of its kind ever held in Canada, drawing expert academics, scientists and policy-makers from around the world. The previous conference was held in Kyoto, Japan, in 2002.