Listen to this article
Estimated 4 minutes
The audio version of this article is generated by AI-based technology. Mispronunciations can occur. We are working with our partners to continually review and improve the results.
A lot may have changed in New Brunswick in the 12 years since a moratorium was imposed on shale gas exploration.
But one thing hasn’t: what’s under our feet.
We know there is some shale gas trapped in rock under the soil.
The New Brunswick government estimates the province has 77 trillion cubic feet of shale gas in two known gas fields. In comparison, the much larger province of Alberta has 3,455 trillion cubic feet.
In southern New Brunswick, the McCully Field near Sussex has an estimated 67.3 trillion cubic feet of gas, and to the northeast of it, the Stoney Creek Field near Hillsborough has a further 10.9 trillion cubic feet.
How did it get there?
Shale, the type of rock that could potentially hold gas, can be found in a large part of the province, from Bathurst down to Fredericton, then east to Sackville.
To find out how gas got into the shale we have to go back 350 million years to the carboniferous period, when what is now New Brunswick looked very different.
“At that time in southern New Brunswick there was a very vast setting, where marine conditions were prevailing,” said Denis Lavoie, a retired geologist who worked for 30 years at Natural Resources Canada.
Not all shale rock has gas, and geologist Denis Lavoie said the New Brunswick shale that could hold gas is in the southeast. (CBC)
Lavoie said the large ocean that covered southern New Brunswick was populated by small organisms.
When they died, they settled to the bottom of that ocean and, after millions of years, created a layer that was then buried under hundreds of metres of rock.
“The organic matter then is transformed [into] hydrocarbons from the effect of increased temperature,” Lavoie said.
In New Brunswick’s case, the hoped for hydrocarbon would be natural gas.
How much is there?
If we know there is shale gas in the shale, the next question is how much shale gas is trapped in that shale?
More than a decade after Brian Gallant’s Liberal government put a moratorium on shale gas development in New Brunswick, a different Liberal government is looking at ending it.
The short answer, according to Dave Keighley, a professor in the department of earth sciences at the University of New Brunswick in Fredericton, is simple. We don’t know.
“The only way you find out is … dig or drill,” Keighley said.
That’s not to say there haven’t been efforts to get more information about how much gas there may be.
UNB geologist Dave Keighley said estimates may give us an idea of how much gas there is, but the only way to know for sure is to dig. (Aniekan Etuhube/CBC)
Before the moratorium, some seismic testing was done in various regions of the province.
Keighley said this gives an idea of the volume of shale and how far down that rock is.
It’s also possible to calculate the volume of gas the rock could potentially contain, but until there’s digging, we’re in the dark.
Estimates are just that, estimates.
Keighley said estimates in New Brunswick, based on the most generous criteria, suggest those areas of the province have a 10 to 50 per cent likelihood of containing shale gas.
“That’s the best case scenario, we don’t know,” Keighley said.
Lavoie said it’s important to understand that having shale rock doesn’t automatically mean there is shale gas.
“In some areas you have shale, but [it was] not buried deep enough, so the organic matter hasn’t been transformed, so you don’t have hydrocarbons in those shales,” Lavoie said.
“So you have to have a good understanding of what is the quantity of organic matter in the rock and to which depth these rocks were buried.”
Lavoie said the best chance for shale gas is in southeastern New Brunswick, where the rocks are younger and have a higher probability of having the organic matter needed to produce hydrocarbons.
In central and northern areas the rocks are older, and have less organic matter, which makes the possibility of significant gas deposits “minimal.”
This story is part of the series Shale Gas Development Revisited: What’s Changed. CBC New Brunswick is taking a closer look at what has changed since the provincial government put a moratorium on shale gas exploration in New Brunswick in 2014. The government is now reviewing the moratorium until January 2027, when it will decide whether to lift it. If you have a story or tip to share on this topic, please write: [email protected].
