The Alberta Energy Regulator has ordered Canadian Natural Resources Ltd. to restrict steam injection and take other precautions at its Primrose and Wolf Lake high-pressure, cyclic steam stimulation (CSS) project in the Cold Lake region of Alberta.
It took the action in responses to the fourth release this year of bitumen emulsion to surface in the project area 55 km north of Bonnyville.
Earlier this year the AER ordered the suspension of steaming in the Primrose East section after three bitumen releases. CNRL on June 24 reported the fourth release into a water body on the Cold Lake Air Weapons Range at Primrose South.
In response, the AER ordered further measures, including the suspension of steaming within 1 km of the Primrose South incident, restriction of steam throughout Primrose North and South, enhanced monitoring, and accelerated clean-up.
The AER is investigating the releases, which haven’t threatened public safety.
CNRL reported average production in the Primrose-Wolf Lake area of 109,000 b/d in the first quarter this year. The Lower Cretaceous Clearwater formation productive in the area requires CSS, the company says.
CSS involves injection pressures much higher than those involved in steam-assisted gravity drainage, another thermal recovery method used widely in the Alberta oil sands.