Wringing bitumen out of Alberta’s oil sands is a large-scale mining operation that requires processing or upgrading of the mined bitumen to convert it into a synthetic oil. A refinery then turns the oil into a lighter petroleum product such as gasoline. A byproduct of the production of hydrogen – which is used to upgrade the bitumen – is carbon dioxide. There is broad consensus that too much carbon dioxide in the atmosphere generated by human activity is tied to climate change.
To reduce the amount of carbon dioxide being emitted into the atmosphere, the Quest Carbon Capture and Storage (CCS) Project is being built in Canada by the Athabasca Oil Sands Project (AOSP) joint venture. The first commercial-scale CCS project for an oil sands operation, the Quest CCS is being built by Shell on behalf of the AOSP joint venture owners – Shell, Chevron and Marathon Oil – with funding support from the governments of Canada and Alberta.
The Quest project will capture and permanently store in porous rock more than a mile underground approximately 1 million metric tons of carbon dioxide per year from Shell’s Scotford upgrader near Edmonton, Alberta, which processes bitumen from the Athabasca oil sands.
Among the challenges of the project were making it more energy-efficient and reducing its cost to make it economically feasible. “To put it into simple terms, it uses the design techniques for offshore oil platforms to reduce the footprint of the capture facilities and applies them to an onshore facility,” Project Manager Anita Spence explains. “So it basically condenses and reduces the space and bulk materials required to build the facility and moves about 50 percent of the construction off-site, thus reducing our cost substantially.”
The Quest CCS was designed in 69 modules, built offsite in Edmonton at KBR yard and installed by Fluor. Each module fits inside the maximum shipping dimensions of 26 feet wide, 26 feet high and 120 feet long and weighs from 150 to 250 metric tons.
The modules were designed to stay within Alberta’s heavy load shipping size because they had to be transported by truck. “If you were closer to the coast, you could build bigger modules, but with us being landlocked, we had to fit inside the shipping size,” Spence notes.
Once assembled, the modules with their piping, pumps, cabling, motor controls and valves are connected. “We’re going through the final welding and bolting up of the connections between all those modules, as well as tying in all the cable we had installed,” Spence says.
“Flowserve Corp. did both the valves and a lot of the pumps,” Spence says. “They’re one of our global suppliers for pumps and control valves, so we used them on this project as well as many others.”
All the equipment will be accessible for routine maintenance and repairs. “The only thing that was not modularized was the compressor building itself, which is too large to contain inside that shipping size,” Spence says.
“We did a fair amount of integration with the existing facility, both with the high-pressure steam and low-pressure steam system, as well as using some of our heat to heat up the process stream,” Spence continues. “So we got that tight integration and reduced the amount of energy we were actually going to use to capture the CO2. The Quest process design, completed by Shell Global Solutions Inc., basically, uses the same processes that you would use in a natural gas facility that remove hydrogen sulfide and CO2 to make it salable.”
At the Quest facility, the carbon dioxide will flow into vessels and be absorbed in a chemical solution. Heating the solution will release the carbon dioxide, before it is compressed into a fluid for piping more than 35 miles north to three injection wells, where it will be injected into the porous rock underground for permanent storage.
The Quest project will inject the carbon dioxide back into the ground where it originated and was stored for millions of years. “We’re reversing that process, in that we’ve found a saline aquifer about two miles down called the Basal Cambrian Sandstone,” Spence says. “We inject CO2 down into that porous rock, and it will be contained there because of the salt and shale rock structure above it, which is similar to where we would typically find natural gas.”
Since 2008, community meetings have been held once or twice annually by the joint venture to explain the project to residents and how it would affect them. “We talked with them about our proposed route selection for the pipeline and got their comments on that,” Spence recalls. “We chatted with them about the overall schedule and how that might impact them if they were traveling and what hours we would be working. We basically talked them through the regulatory process and told them where and how to get involved in that. Then we talked a lot about the underground storage and what the reservoir looked like, how the CO2 would be contained, that we would be measuring and monitoring it over time, and what technology we will use to ensure it stays where we put it and none of it will migrate out.”
Installing the carbon capture facility is expected to reduce direct carbon dioxide emissions by up to 35 percent from the Scotford upgrader when it is complete. The Quest plant is scheduled to be mechanically complete by the end of December. Commissioning and start-up will continue through 2015. “Our commitment to the government is to have the CCS at sustainable operation by the end of 2015,” Spence says.
The CCS plant requires firm footing. “We have more than 1,000 steel piles driven onsite, and they all have concrete blocks on top of them with anchor bolts that allow the modules to get bolted down when they arrive,” Spence relates. “That was all the early work we did late in 2012 and through the summer of 2013. The modules started to arrive in November of 2013, and we installed the last of the modules in August.”
A substantial crew of workers is required for the massive project. “We have about 480 guys onsite between the pipe-fitting, boilermakers, electricians, instrumentation trades, as well as laborers to tie the whole thing together,” Spence estimates. “We expect a couple more months at that level, and then it will start to decrease as we approach our mechanical completion date at the end of the year.”
Timing is Everything
The Quest CCS is being built next to an operating upgrader. For the last two years, portions of the CCS plant have been connected to various areas of the upgrader. Earlier this year, the CCS plant was tied in to the expansion of the upgrader. One more shutdown will be required in spring 2015 to connect the CCS to the first hydrogen unit that is part of the base plant and achieve full capacity.
“We’ve also done some of the work through what we call hot taps, where we actually tap into the lines while they’re still operating,” Spence reveals. “So some of the utilities we’ve done in that fashion in order to allow us to come onstream before that final base plant comes downstream next year. This will give us the flexibility to bring the capture facility up on the hydrogen units before the base plant turnaround and give us confidence that we can get all the bugs out before 2015.”
At the Alberta oil sands in Fort McMurray, bitumen-laden rock close to the surface is removed from an open pit mine and transported to the upgrader in Scotford. “That’s where we separate it out and make it into a usable product,” Spence explains. “It goes into a refinery and gets split up into jet fuels and diesel.”
The carbon dioxide is a byproduct. “Our upgraders have hydrocrackers,” Spence says. “They use the addition of hydrogen to break the big heavy carbon chains that the bitumen consists of. The upgraders do the first big split and take that heavier oil and break it into a lighter component, and that is what feeds our refinery. We actually have three hydrogen manufacturing units that split methane into hydrogen and carbon dioxide. So this is where we’re capturing our CO2 from.”
Because of the involvement of the governments of Alberta and Canada, “A lot of knowledge sharing is going on around Alberta about carbon capture sequestration,” Spence stresses. “That is a key component with a province that is so heavily into hydrocarbon to keep a sustainable operation. There’s been a fair amount of knowledge sharing through various conferences and through government websites, as well as a lot of others, that want to build a carbon capture facility.”
Spence hopes the Quest CCS will move carbon capture technology forward. “The desire of the project is that this will spur more CCSs to be built, especially if we can show how the next group of projects can be done for a lesser cost,” Spence says. “The intent is to teach others so they can do it for lower cost than we did. We expect this to spur more CCS projects.”