Shell Canada says the Quest project at its Scotford Upgrader is working better than planned and demonstrating that carbon capture and storage (CCS) is a real solution to climate change.
The company announced on September 15 that since start up a year ago, Quest has captured and stored a one million tonnes of CO2, ahead of schedule.
Here’s what else Shell's former Quest project lead Tim Wiwchar (currently Shell’s oilsands portfolio manager) had to say about the challenges in bringing the project to reality and its early achievement.
Shell said that if Quest were built again today, it would cost 20-30 per cent less to construct and operate. How so?
Quest was built using Fluor's third-gen module technology which all fits on the back of a flatbed truck and can be shipped to site. All the drawings, the process flow diagrams, all that engineering is done and that information is available to anyone who wants to build this. So that accounts for part of the lower price.
Also we now have better familiarity with the logistics, equipment selection and there is greater certainty around contracts and procurement.
On operating costs, we're seeing operating costs reduced by that same amount. Some of that is the low cost environment for power, but the subsurface is also more porous than expected.
We're injecting into its rock with salt water in it. So you displace the water with the CO2 and the CO2 gets trapped in the pores. Those pores are bigger than what we first thought. The CO2 goes into it easier, which means that we don't require as much pressure and electrical power to run the compressor to get the CO2 in there. That alone represents up to about a third of our operating cost.
Any other surprises so far?
We're starting to see some positive developments in the subsurface. In the very unlikely event that there is a crack in the cap rock, the CO2 seems to be able to act as a sealing mechanism as well. So you almost have some self-sealing activity going on down there.
What monitoring is in place to understand what’s going on subsurface?
One of the requirements was that we have a measurement, monitoring and verification program. So we’re using a lot of the existing subsurface geological technology used in oil and gas exploration. We're monitoring groundwater for local residents. We also monitor the soil gas CO2 for vegetation and we monitor the atmosphere.
We started monitoring before injections began, so we have a baseline. We will monitor for the full duration of operations and for 10 years after we close the valve.
Why was sequestration in a saline aquifer chosen over using the CO2 in enhanced oil recovery (EOR)?
When we went into the CCS competition, we understood that there were EOR applications but, at that time, we also recognized that governments don't necessarily recognize EOR for storage. So we want to do Quest with permanent storage for better recognition that the CO2 is permanently stored.
How much CO2 storage capacity is there in the aquifer you are injecting into?
The saline aquifer we're injecting into extends from the B.C./Alberta border and runs southeast to the Saskatchewan/Manitoba border. So it's quite large. We only have a very small portion of that, a 3600 km² zone. Even injecting 1,000,000 tons per year as Quest will do for 25 years, we will only use five to seven per cent of the capacity in our zone.
What does Quest's early success mean for Alberta?
It helps illustrate that CCS [here] is doable. The technology for the capture side in oil and gas is proven, but one of the uncertainties that we had was the subsurface dimension. I think what we're showing here that Alberta and Saskatchewan have saline aquifer reservoirs suitable for CCS.
As we get our costs down—and not just because of the low cost environment but true reductions in operations and capex—and as the carbon price goes up, we will be able to get to that point where we can do CCS with permanent storage and have a break-even project.