CALGARY – The Alberta Energy Regulator has ordered Canadian Natural Resources Ltd. to restrict the amount of steam it pumps into two oilsands projects following four spills earlier this year.

The move comes three weeks after the AER reported an emulsion of oilsands bitumen and water had been released into an unnamed water body on the Cold Lake Air Weapons Range in eastern Alberta.

The watchdog says Canadian Natural must restrict steam injection, enhance monitoring and speed up clean up efforts at its Primrose and Wolf Lake projects, which use a method called high-pressure cyclic steam stimulation to extract the bitumen.

“Although there have been no risks to public safety, until we investigate these incidents, better understand the cause of these releases, and what steps CNRL will to take to prevent them, we are taking these measures as a precaution,” said AER CEO Jim Ellis.

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The AER ordered the suspension of steaming operations within the eastern part of Primrose earlier this year following three bitumen emulsion releases.

In late June, Canadian Natural reported a fourth release, prompting the AER to order CNRL to take further measures, including suspending steaming within one kilometre of the leak and restrict steaming throughout the northern and southern parts of Primrose.

High pressure cyclic steam stimulation — sometimes described as a “huff and puff” method of extraction — involves injecting steam into a reservoir through a well, letting it soak for a while and then drawing the softened bitumen to the surface through the same well.

It differs from steam-assisted gravity drainage, or SAGD, which uses two wells — one to inject the steam, and one right below it to flow the bitumen to the surface. The reservoir is also fractured using cyclic steam, whereas in SAGD it is not.

Greenpeace campaigner Mike Hudema said it’s “very concerning” that it’s only now just come to light that the CNRL sites have suffered four spills this year.

“Apparently it’s four strikes in this province before the Alberta Energy Regulator takes any real action to protect the environment,” he said.

“This is a culturally significant area for the Beaver Lake Cree and it’s time the Alberta government gave us the transparency on this issue that Albertan’s deserve — pictures and up to date statistics are a minimum and we can’t even get that.”

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He said the incidents also raise questions over the safety of high pressure cyclic steam stimulation.