CALGARY — Research commissioned by Cenovus Energy Inc. has found carbon dioxide injected into the company’s oilfield in Weyburn, Sask., is staying put in the ground and is not seeping into a nearby farm.
The Calgary-based oil company (TSX:CVE) said Tuesday that it hired several third-party specialists to do an assessment and they determined it is not to blame for the CO2 found on Cameron and Jane Kerr’s property.
“As always, we take our landowner concerns very seriously and we felt it was important to commission this study to address the matters raised earlier this year,” Brad Small, vice-president of Cenovus’ Saskatchewan oil and gas operations, told reporters.
“The results, which have been peer reviewed, should provide complete assurance to landowners and the public that the CO2 we are injecting is staying put and that our Weyburn operation is safe.”
The findings of a separate independent study — by the International Performance Assessment Centre for Geologic Storage of Carbon Dioxide (IPAC-CO2) — are set to be released in about two weeks in Regina.
Cenovus pumps CO2 into the aging Weyburn field in order to push more oil out of the ground in a process called enhanced oil recovery. It also traps the climate-change causing gas underground, rather than letting it escape into the atmosphere.
Cenovus, which operates the unit on behalf of 23 other partners, buys CO2 from a coal gasification plant in North Dakota and pipes it into the Weyburn site. Because that gas originates from coal deposits formed millions of years ago — and the CO2 tested on the Kerr property was found to have formed in modern times — lead scientist Court Sandau said there’s no way gas leaked from the Cenovus field.
During the first round of tests this summer, one spot on the southern edge of the Kerr property was found to have higher levels of CO2 than a control area 10 kilometres away where there is no oil and gas activity.
“But it was natural in origin and it was new carbon, not old carbon,” said Sandau, founder of ChemistryMatters. CO2 levels during a second test of that spot were found to be lower.
It’s common for natural “soil respiration” processes to elevate levels of CO2 and it’s unlikely such an occurrence would be harmful. CO2 isn’t inherently toxic, Sandau said, but it can cause asphyxiation in an enclosed space.
“Here, in the middle of the Prairies, the CO2’s just breathing in, breathing out. The concentrations are not going to accumulate to cause effects.”
The Kerrs say that in 2005 they began noticing algae blooms, clots of foam and multicoloured scum in two ponds at the bottom of a gravel quarry on their land and that small animals were regularly found dead a few metres away.
Ecojustice, the non-governmental organization advising the Kerrs, said it will examine the Cenovus research and is also awaiting results from IPAC-CO2 study, due Dec. 12.
“The reality is that Cenovus Energy and the Saskatchewan Ministry of Energy and Resources failed to properly investigate the Kerrs’ concerns during the last six years,” said Ecojustice staff lawyer Barry Robinson. “After years of requesting an in-depth investigation on their property, the Kerrs are glad to see that Cenovus has finally conducted an investigation of the potential impacts carbon capture and storage may have on their property.”
In July of last year, a study by a Saskatoon-based consulting company found unusually high CO2 and methane levels in the soil. Sandau did not comment on those findings, as he did not see first-hand the sampling and testing practices that yielded those results.
“What I can say is that the study we did used state of the art technologies,” he said. We had peer review before, during and after the study to help guide us to our techniques that we should be using to do the sampling and the analysis.”
The IPAC study, which includes researchers from Canada, the United States and Scotland, looks at the ratio of carbon dioxide at the Kerr farm in relation to other gases.
“It’s not the absolute amount of carbon dioxide that’s important, that might be an indication that it’s anthropogenic, or man-made, versus natural,” she said. “What’s important is the ratio of the carbon dioxide and the oxygen and nitrogen.