Bitumen from one of Canadian Natural Resources Ltd.'s projects has bubbled up into a nearby body of water at one of its oil sands operations, killing waterfowl, frogs, tadpoles, beavers, shrews, and prompting the Alberta regulator to limit the company's extraction efforts around Cold Lake.
The Alberta Energy Regulator on Thursday ordered CNRL to suspend underground steaming – which melts bitumen and allows it to rise to the surface in pipes – within one kilometre of the unnamed body of water at its Primrose South operation. The regulator imposed other steaming restrictions throughout CNRL's Primrose North and South properties and the company must enhance its monitoring systems.
Oil leaks of any kind, whether from trains, pipelines, or wells, are increasingly damaging to energy firms trying to buff up their safety credentials. Spills and leaks killing animals attract even more criticism.
CNRL's most recent leak, reported June 24, is unusual because it involves the extraction process, rather than infrastructure or transportation methods.
The AER said it has not seen this style of leak seep into water before, which could put a dent in the argument that underground oil sands extraction methods are greening Alberta's energy industry.
The contaminated body of water is on the Cold Lake Air Weapons Range, where CNRL uses a process called high pressure cyclic steam stimulation to suck bitumen out of the ground. The Calgary-based company uses wells to pump high-pressure steam below the surface to soften the bitumen while water dilutes and separates the bitumen from the sand. The pressure creates cracks, allowing the bitumen to flow back into the steam injector wells.
The pipes did not leak, AER spokesman Bob Curran said. Instead, bitumen leaked into the slough from the bottom.
"It is coming through the ground somewhere. We don't know what caused it," Mr. Curran said. "It is leaking directly into the body of water."
Earlier this year, the AER sanctioned CNRL, which did not return messages seeking comment, for three bitumen leaks at Primrose East, another section of the property. Bitumen leaked to the surface, although on land rather than into water, Mr. Curran said. The regulator has not seen that type of surface leak since 2009, he said. The AER previously ordered the company to halt steaming within Primrose East because of these leaks.
The affected area is about 40 hectares, Mr. Curran said. He does not know how much bitumen leaked.
The Alberta's Environment and Sustainable Resource Development department confirmed the list of dead animals and said a wildlife team is working to rescue other animals with live traps. A veterinarian is assessing oiled animals.