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EOR research in final stages
Gary Park For Petroleum News
International researchers are involved in a study that is being closely watched around the world by governments and companies anxious to know whether there is a future in burying carbon dioxide, the leading source of greenhouse gas emissions.
They are in the final stages of a project to assess what has happened to more than 7 million metric tons of CO2 that has been injected into the Weyburn oil fields of southeastern Saskatchewan.
The initial, C$42 million phase of the Weyburn project has involved shipping pure CO2 from a North Dakota gasification plant via a 190-mile pipeline.
The gas is liquefied in Saskatchewan and pumped into underground deposits of oil-rich rock, where it acts like a solvent to separate the oil from its host rock to improve recovery from oil fields operated by EnCana and Apache Canada.
In their preliminary findings, the researchers concluded that less than 3 percent of the CO2 injected into the Weyburn reservoir will leak out over 5,000 years.
Now, the research emphasis, supported by the International Energy Agency, Natural Resources Canada and the U.S. Department of Energy is on monitoring and risk assessment with the objective of applying the technology to other storage sites developing methods of preventing leaks. Critics: sequestration too expensive Environmental critics argue CO2 sequestration and storage is too expensive and too dependent on government incentives.
They also worry about an escape of CO2, a concern that is downplayed by the Petroleum Technology Research Center in Regina, Saskatchewan, where scientists doubt there could ever be a catastrophic CO2 release.
But they do concede that CO2 could find its way to the surface through some of the 1,000 wells drilled in the Weyburn area.
The research team views the current phase of the project as a chance to compile a “rich but raw data resource (which) must be unassailably credible — bulletproof — if it is to serve as a platform for risk assessments of geological storage projects worldwide.”
But the project has been bogged down over the last year as government, industry and researchers have wrestled with negotiations to decide how they will share the “intellectual property” accumulated from the study.
The final agreement allows companies to protect information on how injecting CO2 enhances oil production, while allowing the researchers to publish data on CO2 storage and monitoring.
Depending on the results, the technology research center may move to a C$59 million project to inject 1,350 metric tons of CO2 per day into saline aquifers that are thought to pose a reduced risk of leaks.
Also on the waiting list are possible undertakings by Shell Canada to capture CO2 at its Edmonton refinery complex and use it for enhanced oil recovery, while ARC Energy Trust and Penn West Energy Trust are contemplating CO2 sequestration for enhanced recovery projects.
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