Process available to competitors, academics, government; ‘no strings attached’
BY KAY CASHMAN FOR GREENING OF OIL
In late August, Shell Canada announced the start-up of a commercial-scale atmospheric fines drying field demonstration project for managing tailings from its Muskeg River oil sands operation in northern Alberta, part of an industry move to reduce the impact of oil sands mine tailings on the environment.
Tailings are a mixture of fine clay, sand, water and residual bitumen produced through oil sands extraction.
When tailings are released into a pond, the heaviest material — mostly sand — settles to the bottom, while water rises to the top. The middle layer, often called mature fine tailings, is made up of fine clay particles suspended in water. These particles remain suspended in water for long periods of time, making it necessary to expand tailings facilities or find new technology to speed up this process.
Shell’s atmospheric fines drying process, which cost the company $30 million to develop, can turn them into dirt in a matter of weeks.
The company said in its Aug. 26 press release that it is working with a number of others in the industry and with research institutes to advance this, and other technologies, as fast as practical.
“Historically, around any technology, companies look to protect the intellectual property. They look to get value for the money they've invested in advancing that technology. That's not the model that we have anymore,” John Broadhurst, the company's vice-president of heavy oil development, told reporters Aug. 26.
“This information is important for the industry, it’s important for academics, it’s important for the government,” he said. “We'll make it available, no strings attached, no intellectual property, no expectation of money. This is just something that we need to do our part.”
Water can be re-used
Shell’s new technology uses a large barge to collect mature fine tailings from its tailings pond and then transferring the tailings to a drying area. Flocculants (chemical agents) are then added to the tailings to help bring the fine clay particles in the tailings together into a sludge-like consistency before spraying them on a sloped surface to help speed the release of water from the clay. (Shell compared the process to laying laundry out to dry on a hillside.)
The released water runs down the sloped surface to a collection area and 85 percent is returned to the external tailings facility for re-use in the extraction process.
Shell dries the remaining deposits further to meet strength and reclamation requirements.
The company said the technological breakthroughs in its process are in the flocculant it is using and the placement of the sludge so that water efficiently drains away.
Shell received regulatory approval for operation of the atmospheric fines drying field demonstration project on Aug. 6 after successfully testing the process at its tailings pilot plant at the 75-acre Muskeg River Mine.
The commercial-scale demonstration project, which will process as much as 20 percent of the mine’s mature fine tailings, is expected to dry out 250,000 tonnes of tailings by year’s end.
“The issue is not whether we, as an industry, can reclaim tailings,” said John Abbott, executive vice president, for Shell’s heavy oil business. “The issue is whether we can do it better and do it faster. We believe that working with others is key towards developing solutions that will allow us to accelerate the pace of reclamation and meet the expectations of the ERCB’s Directive-074,” he said, referring to the Alberta’s Energy Resources Conservation Board’s directive that was issued in February 2009 and which requires oil sands producers to dry out 50 per cent of their fine tailings by 2013.
“We are actively working to promote broader industry collaboration in this area and Shell will openly share the outcome of this demonstration project with industry players, academia, regulators and others interested in working on tailings solutions,” Abbott said.
He told reporters that the atmospheric fines drying process is not a “silver bullet,” but will instead serve as one of a portfolio of solutions.
The process could eventually be applied to all tailings from both Shell’s current Muskeg River Mine and future Jackpine Mine operations, the company said in its release.
Pembina Institute spokesman Dan Woynillowicz called Shell’s plan “absolutely a step in the right direction,” but said it’s too early to speculate about how the technology will work.
Major oil sands player Suncor Energy is also developing a technology to speed up the reclamation of liquid tailings. CEO Rick George has said the company might license the technology to make it available to others.
Suncor was the first oil sands producer to meet the requirements of Alberta’s Directive 74. Imperial Oil recently received government approval for a clean-up plan that will comply with those rules by 2018.
Shell Canada Energy is 60 percent owner with Chevron Canada (20 percent) and Marathon Oil Sands (20 percent) of the Athabasca Oil Sands Project, which includes the Muskeg River Mine and Scotford Upgrader, with a capacity of 155,000 barrels per day.
Kay Cashman can be reached at email@example.com
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