After leaving Illinois, the SECURe team headed to Canada on the next leg of their fact-finding mission. Here, Edward Hough (British Geological Survey) and Michael Kupoluyi (Risktec) describe a day of learning and insight at Banff National Park, Alberta.
Edward Hough: Reaching the goals agreed in the Paris Agreement to reduce greenhouse gases will require drastic changes to energy usage, including using gas rather than coal and generating hydrogen allied with carbon capture and storage (CCS). Winning gas from new sources, such as shale, and sealing CO2 in deep storage rocks are both ways to contribute to these aims.
As a geologist, I have learned about rocks from where they can be easily seen – at outcrops. Alberta, Canada, is one of the few places where CCS and shale gas are both operated at commercial scale (in Europe, there is only one active shale gas site and only a handful of CCS pilot sites).
Since Alberta is located in the foothills of the eastern Rocky Mountains, a roadside geology field trip has allowed researchers on the SECURe project to understand the relevant rock types used in shale gas (Carboniferous shales) and CCS (much older Cambrian sandstones and limestones).
With knowledgeable and insightful explanations from our guide, Kevin Parks, Chief of the Alberta Geological Survey-Alberta Energy Regulator, we were able to understand the relationship between different rock types and formations and observe their character and vast scale.
We gained an appreciation of how the geological history has directly influenced the deposition of the CCS-host rocks and the source-reservoir-seal rocks of shale petroleum systems, allowing us to place the shale and CCS industries in a geological context in a way that is simply not possible at the moment in Europe.
To succeed, these technologies need an appreciation of the subsurface – the rocks, their behaviour and the potential impacts of exploiting them. Seeing these rocks in their natural setting has allowed us to do just that, and greatly aids in our development of good practice recommendations that can support their development in Europe.
Michael Kupoluyi: This trip through the Banff National Park has shown me the extent of natural variability of geological formations and how important it is for site selection processes to be carried out to ensure that sites with suitable geology are selected.
An example was the Castle Mountain formations that are stratigraphically equivalent to the CCS disposal zone at the Quest CCS site near Edmonton. This is a similar case for the Devonian Fairholme Group rocks, which are correlative to the enhanced oil recovery-CCS target zone at Enhance Energy’s site east of Red Deer.
For the SECURe project, it is necessary to understand that the extent to which these site studies are carried out effectively directly affects the uncertainty over any assessment of the effectiveness of geological containment for a specific site.
Some basic tectonic concepts were also described during this trip, especially the fault mechanics leading to the formation of the Rocky Mountains. The level of characterisation of faults such as these near sites during modelling is related to the level of uncertainty in the output seismic data.
Another interesting point is the amount of information provided about these formations and it begs the question of just how much of this information is utilised by operators and what are the associated impacts.
(Photo: Edward Hough, BGS (left) and Michael Kupoluyi, Risktec on the SECURe fact-finding fieldtrip to Banff National Park. Photos: Philippa Parmiter/Michael Kupoluyi. Montage: Indira Mann)