Locking CO2 Underground 

Research & Development

“The idea is we can store enormous amounts of carbon dioxide into very compact form.”
- Jocelyn Grozic, Schulich School of Engineering

Two professors at University of Calgary (U of C) are looking at how to take CO2 from oil and gas operations and lock it underground in gas hydrates.

Gas hydrates are structures in which – under specific conditions – water molecules bond together to form an ice-like cage that encloses a gas molecule.

While studying how to get methane out of hydrates to use as fuel, the professors at the Schulich School of Engineering at U of C decided to start exploring how to put carbon dioxide in.

“Our work is mainly related to gas hydrates and the energy recovery of methane gas from gas hydrates to use it as an unconventional source of natural gas,” says Jocelyn Grozic, associate professor of civil engineering at Schulich.

But because hydrates are so compact, they are also an option for storing carbon dioxide (CO2). “The idea is we can store enormous amounts of carbon dioxide into very compact form,” Grozic says.

She and Mehran Pooladi-Darvish, an adjunct professor of chemical and petroleum engineering at Schulich, are working on a three year study funded by the Natural Sciences and Engineering Research Council.

A mini reservoir created at the Universityof CalgaryA mini reservoir created at the
University of Calgary

Once in a hydrate, the CO2 can’t get out. “When you get the CO2 into a reservoir that has the right conditions and it contacts the reservoir water and forms hydrates, it’s in a pretty stable form,” Grozic says. In essence, the gas becomes a solid.

Specifically, Grozic and Pooladi-Darvish are exploring permeability to get a better understanding of how fluids move through CO2-hydrate reservoirs.

In her lab, Grozic creates a mini reservoir with sand samples and pushes CO2 through to form hydrates. She measures permeability and other factors.

Pooladi-Darvish takes the data from Grozic’s lab and creates computer simulations of large-scale reservoirs to model how it would work in a variety of actual reservoirs. He projects larger flow rates and volumes, factors in reservoir pore spaces, different processes and injection and recovery well configurations.

“I don’t see much stopping the application of this technology,” says Grozic. “We need to do a little more work on permeabilities – the flow of CO2 through the soil – and look at the economics of it as well.”

Grozic predicts the oil and gas industry could be storing CO2 in hydrates within a decade. “It’s an exciting field,” she says of the storage part of carbon capture and storage research.