Sophisticated system for regional groundwater modelling ensures water sustainability in the oil sands region

Water is a precious resource, and while the sector is rapidly advancing towards waterless extraction techniques, it is still currently an essential component of the oil sands extraction process. Understanding whether or not there will be enough water in the oil sands region to support future growth projects is vital, both for individual operators as well as the larger goal of ensuring prudent water stewardship in the decades ahead.

In 2013, COSIA launched the Regional Groundwater Sustainability (RGS) Project to better understand the long-term availability of non-saline and saline groundwater, which in situ oil sands producers in the South Athabasca Oils Sands (SAOS) region rely upon for makeup water. The RGS looked at a range of future growth scenarios and the kind of demands each would place on five key aquifers in the SAOS region over a period of 62 years (from 2013 to 2075).

The RGS chose to update an existing SAOS regional groundwater model first developed by Alberta Environment and Parks in 2009. But much had changed in the interim, and would again as the project team pursued its research.

“Between 2013 and 2016, when we finished our initial work, there were big changes in the industry due to sharply lower world oil prices,” says Mike Brewster, Senior Supervisor of Geoscience Services, for Devon Canada and Lead for the RGS project. “Earlier forecasts about expected levels of industry growth and water use were no longer sufficient.”

“Right now, the oil sands industry is the only one using water from these deep aquifers,” says Mike Brewster, Devon. “But even if another user does come along, we are leaving at least 50% of the available groundwater — and in all likelihood much more than that — for future generations.”

The RGS team decided to step back and develop three potential growth scenarios. The first, known as the Status Quo, accounted for existing projects or projects near completion, as well as any new project or expansions COSIA members expected to proceed under existing economic conditions. The second scenario, Medium Growth, looked at what might be expected with a modest increase in oil prices, while the final one, High Growth, anticipated the impact of a return to the robust oil prices of 2014.

The RGS then hired Calgary-based Matrix Solutions Inc. to do comprehensive predictive modelling of the demand that would be placed on regional groundwater resources under each of the three scenarios. What Matrix brought to the table was the kind of computing power that was not available when the original regional groundwater model had been developed by the Alberta government a decade earlier.

“By using what’s called elastic cloud computing, we were able to process data much faster and account for many more potential outcomes,” says Louis-Charles Boutin, Senior Groundwater Engineer with Matrix. “It allowed us to have, in essence, hundreds of computers running in parallel at the same time doing predictive simulations. We can then look at the broad distribution of those rather than just run one forward prediction and say ‘we think it’s going to be this number.’”

The results of the RGS study, released in July 2017, indicate that peak water demand by the industry in the SAOS region will occur between 2030 and 2040. But the key finding was that, under all three growth scenarios, including the most intensive one, there are sufficient groundwater resources to meet the future demands of in situ oil sands projects through 2075 without adverse impacts on the sustainability of regional water resources.

Behind that high-level finding, says Mike Brewster, are some factors that should provide further reassurance that regional groundwater resources are not threatened by industry activity. For example, the study incorporated the benchmark that industry use should never draw down aquifer pressure by more than 50%.

“Right now, the oil sands industry is the only one using water from these deep aquifers,” says Mike. “But even if another user does come along, we are leaving at least 50% of the available groundwater — and in all likelihood much more than that — for future generations.”

Moreover, the latest forecasts are based on technologies currently in use.

“New technologies being developed by the industry are aimed at improving water efficiency,” says Mike. “So, if anything, the demands placed on regional water resources should actually be less than what’s forecasted by this model.”

The updated and improved regional groundwater model is now available for use by both COSIA member companies and Alberta Environment and Parks. Incorporating the best available science, the model provides a leading-edge tool for evaluating groundwater flow. It will also help identify or anticipate potential pressure points within the region.

“This will allow us to better evaluate and monitor the effects of water use across the five aquifers in the region,” says Mike. “The model can help identify safe thresholds. If we see water levels potentially dropping below these in a particular area, it would trigger actions to ensure the continued sustainability of regional groundwater resources.”

Contributors

Mike Brewster, M.Sc., Senior Supervisor of Geoscience Services, Devon Canada

Louis-Charles Boutin, P.Eng., Senior Groundwater Engineer, Matrix