Example of large fractures in earth that continue to seep bitumen at one of four well sites operated by CNRL at the Cold Lake Air Weapons Range. Photo: CNRL, September 2013.
Researchers of an independent report on one of the largest ongoing oil releases in Alberta history say the provincial regulator and industry must do more to inform the public about the scale and impact of massive bitumen seepage in the oil sands.
For nearly a year now, more than 12,000 barrels of bitumen mixed with water have seeped through several long cracks (some as long as 100 metres) in the forest floor near four wells owned by Canadian Natural Resources Ltd. (CNRL) in the Cold Lake region.
To date, the Calgary-based company has spent nearly $40 million in cleanup operations that have involved the removal of 70,000 tonnes of earth. It also pumped 404,378 cubic metres of water out of a small lake to clean up two large bitumen fissures.
CNRL says the cause of the extraordinary seepage at its Primrose facility is due to a failed or partially failed wellbore, but other observers suspect that the formation was over-pressurized.
The Alberta Energy Regulator said in a November 2013 press release that it has reached no conclusions about the cause and is actively investigating it.
But the report argues it’s highly unlikely that four wellbores six kilometres apart would fail at the same time, and suggests the company has probably fractured protective caprock overlaying bitumen formations.
"Both the Alberta Energy Regulator and CNRL have been slow to provide information and the information provided has been sparse and frequently inaccurate," says Peter Lee of Global Forest Watch Canada, and one of the report’s authors. Global Forest Watch Canada is a network of organizations that exists to provide information about development activities in Canada’s forests.
"CNRL is known to be a media-shy company," adds Kevin Timoney of Treeline Ecological Research, a co-investigator. "The Alberta Energy Regulator, despite its public relations statements, remains a secretive agency. Neither excels at providing timely, accurate and complete information to the public. When the failure to inform is combined with major environmental incidents and a regulator that fails to err on the side of caution, the public interest suffers."
Reports on the volume of bitumen released to the surface, for example, do not add up compared to volumes that the company says it has recovered.
It took the Alberta Energy Regulator six months to answer queries about accuracy and reliability of its data on the incident from the two Alberta scientists who wrote the report. Both researchers say they’ve also documented the slow and uneven rate of enforcement of environmental rules in the province.
Given the uncontrollable nature of the bitumen seepage and its impact on groundwater and wetlands, the report also advises that steam injection "operations should be suspended or curtailed until major unknowns are addressed. Over-pressuring of bitumen reservoirs should be prohibited."
On a newly refurbished webpage dedicated to the ongoing event, the company promises that it will "modify how we steam and the growth in steam volumes in successive cycles to provide greater certainty that all fluids remain" in the Clearwater, the formation they are steaming.
How caprock can crack
The bitumen release has set off alarm bells in the oil sands industry, because half of bitumen production from the mega-project now involves companies injecting highly pressurized steam into the ground to recover deep deposits of tarry bitumen.
In the future, 80 per cent of all oil sands production will come from energy-intensive steam injection plants.
Although industry has presented this form of production as more environmentally friendly than open pit mining, the cyclic steam injection process used by CNRL at depths of 400 metres can lift ground cover by as much as 36 centimetres (14 inches) over the course of a month. Pumping the melted bitumen out can result in an equal amount of subsidence too.
Studies on the phenomenon nearly 20 years ago demonstrated that "it is physically possible to appreciably raise the ground surface by injecting fluids underground."
Since 2001, satellite imagery has been used by industry to monitor the progress of steam injection and detect ground deformation. The imagery can also help industry determine "whether linear features exist at the surface that may indicate the presence of weaknesses in the subsurface, such as fractures or even faults."
Secret federal briefing notes obtained by Postmedia reporter Jason Fekete last month show that the government knew about satellite data that showed ground level deformation in the area from 2009 to 2013.
Fekete reported that the satellite data showed that "the values of ground deformation (both subsidence and uplift) at the CNRL operation were often in the range of 10 to 30 centimetres over various sampled 24-day periods." Such data indicates that CNRL may have injected too much steam into the formation.
Many scientists now fear that continuous lifting and dropping of the earth combined with the force of injection near local faults and abandoned wells could fracture holes in the caprock, leading to extensive groundwater pollution and surface bitumen leaks.
Still cracks in the research
The Alberta Energy Regulator has had a team studying the critical problem of caprock integrity since 2009, but has yet to issue any reports or an incidence database as promised on its website.
The incidents are well-known. One event took place at Total’s Joslyn steam plant project in 2006. After the company injected the formation (the cause is still the subject of debate), steam exploded to the surface and created a 300-metre crater in the forest. It took the regulator four years to report on the event.
Similarly, a major release by CNRL at the same project now seeping uncontrollably occurred in 2009 and contaminated groundwater. The regulator did not report on that event until 2013, four years later.
Causation of both events remains unresolved.
"The regulator’s inability to determine the causes of previous caprock failures while allowing high pressure cyclic steam operations to continue in the absence of improved safeguards has imposed unquantified risks to bitumen resources, groundwater and adjacent ecosystems," adds the independent report.
Industry is keenly aware of the risks that highly pressurized steam injection now poses in the region. One operation that steamed formations at depths of 480 to 500 metres below the surface had "experienced steam breakthrough" to the surface. As a consequence, "the operators decided to implement a microseismic monitoring system to further observe the steam pathway from the reservoir to the surface in order to avoid any further breakthroughs to the surface," reports ESG Solutions, a company that pioneered technology to help industry measure small earthquakes caused by energy and mining projects.
A better monitoring program helped the company avoid more engineering mistakes, such as injecting too much steam pressures that might "induce fractures in a caprock layer or reactivate existing faults or fractures, causing communication with a sensitive layer (i.e. an aquifer) or in the case of shallow operations, the surface."
Scientists have also known for years that the uplifting can shear off wellbores in the region. One 2001 study by University of Waterloo researcher Maurice Dusseault reported the failure of 250 wells in the Cold Lake region due to the steam induced expansion and contraction of bitumen deposits.
Noted the Dusseault paper: "Downhole integrity loss often can be repaired, but uphole shear failures at Cold Lake are serious events that could result in the release of fluids to the surface. These cannot be repaired, and the wells must be abandoned. Multiple uphole casing failures have caused the abandonment of an entire pad of wells resulting from destabilization of the shale zone where shear is concentrated."
No-steam-injection order issued
To date, it is not known how much bitumen has seeped underground into groundwater or other formations or when it will stop seeping through fissures in the ground.
The Alberta Energy Regulator has imposed a no-steam-injection order for the entire Primrose East area.
The report concludes that "expansion of in situ methods of bitumen exploitation across Alberta is outpacing the increase in knowledge of the potential below-ground and surface impacts of these methods. By the time the effects of these methods are sufficiently understood, it may be too late to remediate."
Moreover, continued use of cyclic steam injection "may result in large and unpredictable costs, and those costs will not be borne by the energy companies but by future generations of Canadians."
23 different groups asked for a public review of safety regulations for steam plant operations last August.
The Alberta Energy Regulator denied the request, saying that "[cyclic steam stimulation] and high pressure cyclic steam stimulation have been successfully used as bitumen recovery techniques in Alberta for many years" and that a public inquiry would "not provide any new information that may be able to support or guide regulatory change."
The Alberta Energy Regulator is 100 per cent funded by industry.