November 2019, Vol. 246, No. 11

CO2 Pipelines

Alberta Carbon Trunk Line About to Come on Line

By Michael Reed, Editor

The Alberta Carbon Trunk Line (ACTL) project in Alberta, Canada, is a massive undertaking. It consists of a 150-mile (240-km) pipeline, which will gather 14.6 mtpa of CO2 when it reaches full capacity. 

To gain perspective on the size of this project, this number represents about 20% of all current oil sand emissions and would have the same effect as taking every car in Alberta off the road. 

At full capacity, the ACTL project will be the largest carbon capture, transportation, utilization and storage (CCUS) project in the world that only uses CO2 originating from human activity. 

“We’re kind of on the home stretch in a sense,” said Wolf Midstream’s Cullen Colville, manager, Project Engineering. “Right now, we’re expecting the pipe that we need to be in the ground by the end of October.”

The system consists of three segments of pipeline: about 2 miles of 24-inch pipe, 8 miles of 12-inch pipe and a larger segment of 140 miles of 16-inch pipe. The company expects to be operating in early November. 

Initiated by Enhance Energy, the ACTL project will source its CO2 from a fertilizer manufacturing plant in Redwater and the North West Redwater Partnership bitumen refinery using gasification. It will initially funnel the collected CO2 to Clive, a field that was discovered in the 1950s and currently produces about 300 bpd.

In order to deliver a project of this nature, Wolf Midstream opted to use pipe that exceeded specifications. 

“It’s all pretty specialized material in terms of the wall thickness, the grade of the steel and the toughness of the steel itself,” Colville said. “All were specified uniquely in consideration of this being dense-phase carbon dioxide service.”

The carbon capture and storage (CCS) technology works on the principle that CO2 has value, despite being a greenhouse gas. Some emitters of CO2 sell it for industrial purposes, for example. 

“We take that CO2 from both of those facilities and compress it prior to putting it in the pipeline into a supercritical state that CO2 transports,” said Jeff Pearson, president of Wolf Midstream’s Carbon Business Unit.

Located at the south end of the pipeline is an oil and gas company that injects the CO2 into the ground at an old oil reservoir that was largely depleted. The CO2 mixes with the remaining oil, which causes swelling and reduces the viscosity in the reservoir, resulting in greater oil production. 

“It gets permanently stored below ground, which is another great social component here,” said Pearson, “The CO2 that would otherwise be hitting the atmosphere is stored permanently underground inside the reservoir rock structure.”

While construction of the project took place in largely rural areas, averting the kind of challenges brought on by dense population and traffic concerns, the ACTL project found its biggest foe to be the weather.

“This has been a very difficult year to construct with the amount of precipitation we’ve had. It has been completely abnormal and above average,” Colville said. “And, of course, when you have a linear disturbance that’s covering several hundred kilometers, good weather is the name of the game.” 

In addition to the heavy precipitation in the spring and fall, February brought record low temperatures to the province, causing frozen ground and the need to “demonstrate a little bit of agility,” he added. 

A Little Extra

As part of the construction process, Enhance instituted a crack propagation study in an effort to determine the appropriate specifications for the pipe. The process involved taking samples of pipe to a laboratory and “encouraging” it to rupture while in dense-phase CO2 service.

The resulting crack propagation and mechanics assessment led to a unique specification for the pipe, not only with the grade and the wall thickness which provides greater flexibility, but also in the amount of energy the pipe is able to absorb. 

“Basically, I suppose, when you boil it all down, we have designed and constructed one gigantic cracker arrester,” Colville said.

Permitting Process

While Wolf Midstream said the fact that the Alberta Carbon Trunk Line was designed to be the first large-scale carbon capture project in the province and didn’t pose any special permitting issues, the process was anything but simple.

“In Western Canada, there are challenges that come up when you’re beginning to engage with stakeholders on any large projects,” Pearson said. 

The company’s predecessor and the original proponent of the ACTL was Enhance Energy, which is still involved at the south end of the project with the enhanced oil recovery.  

According to Pearson, Enhance Energy went through that process, along with an extensive stakeholder consultation.

“It really is a function of time and being accommodating and listening to the concerns of all different groups in the area,” he said. “That process took several years.”

Plans for the ACTL got underway in 2004 but ended up being placed on hold in the wake of the 2008 financial recession. It was restarted in April 2011 after receiving a license for construction and operation but experienced a couple of delays in its production schedule. Construction began in October 2018. 

Pearson said the routing of the pipeline was a direct result of community involvement and addressing concerns about environmental impacts. 

Almost all of the construction work on the ACTL was done by contractors, as Wolf Midstream does not employ a large operating workforce within its carbon business unit. 

“This is our flagship asset, and we are in the process now of building that operating team,” Pearson said. “There were four primary contractors involved in the mainline construction and contract resources in every other aspect in the land operations.”

The company estimates that permanent and temporary labor for the project generated 1,000 new positions through the construction phase.

“Our goal, longer term, is to add more supply, build laterals and grow the system out,” Pearson said. “It was designed, on purpose, to be much larger than the initial volume, so it’s got a lot of excess capacity, which is why it was built so large.”