The Alberta Energy Regulator (AER) released its independent technical review of the ongoing bitumen leaks oozing from CNRL’s Primrose site on Tuesday, pointing to the company’s steaming practices as being at least partially at fault for the “flow-to-surface” events taking place at four separate locations.
CNRL uses cyclic steam stimulation (CSS) to pump bitumen from a reservoir below the protective caprock. According to the regulator, the high pressurized steam along with poorly sealed wellbores contributed to breaks in the shale that account for the above-ground bitumen leaks that have been ongoing since May 2013.
The company admitted for the first time earlier this month in its causation report to the AER that cracks in the caprock caused by too much steam pressure could be a factor in the seepage. Previously the company had maintained that the issue was solely due to wellbore failure.
Along with the report, AER president and CEO Jim Ellis issued a statement indicating that CNRL would not be allowed to proceed with regular operations any time in the near future.
The regulator imposed restrictions on steaming activity at CNRL’s Primrose East site and within 1 km of the Primrose South site in June 2013 after the bitumen leaks were discovered, one of which was found under a lake.
“The AER is not prepared to approve a return to full operations at these sites until all potential risks are addressed and proper requirements are in place to avoid a similar incident,” Ellis said. “This will require a gradual, step-by-step approach that allows us to manage those risks.”
Jackpine trees drenched in oil at Cold Lake. It is surprisingly difficult to find photos of the Cold Lake oil spill because the company, along with the government, are restricting access to the site. Credit Great Plains Tar Sands Resistance
To date, about 1,180 cubic metres of bitumen emulsion has been recovered from the 20.7-hectare impacted area, where cleanup is ongoing. According to the regulator, the bitumen release has now been “contained.”
Erin Flanagan of the Pembina Institute said the report calls into question all of CNRL’s steaming practices, which were found to be the cause of a similar 2009 blowout at one site.
“This technical report confirms that CNRL’s project design and operation are the root cause of bitumen emulsion coming to the surface,” she said in a blog post. “The first such flow-to-surface event happened in 2009, and the leaks currently in question started in June 2013. The technical review has identified CNRL’s steam injection volumes and well spacing as key contributors to these leaks.”
Pembina again called for a broad technical review for CNRL’s entire CSS project to prevent similar accidents in the future.
The investigation into the leaks is ongoing. The independent review panel and the company are continuing to collect and analyze data and will submit final reports in September.