What if you could recover more oil from an older reservoir, and permanently store waste carbon dioxide (CO2) safely underground at the same time? The result would be a multiple win: producing energy the world needs, creating jobs, and helping reduce greenhouse gas (GHG) emissions.
That’s exactly the thinking behind Calgary-based startup Enhance Energy. In early 2020, the company is in the final stages of building a project with an ultimate capacity to inject up to 1.6 million tonnes of CO2 underground annually and produce oil that is 60 per cent less carbon intensive than conventionally produced oil.
The team at Enhance Energy is using a proven technique called ‘enhanced oil recovery’ (EOR) that involves obtaining CO2 from large industrial emitters in Alberta and injecting it into a developed oil reservoir that is near the end of its conventional life. The idea is to flood the reservoir with CO2, which acts like a solvent that reduces the viscosity of the remaining oil so it can be pumped to the surface.
The reservoir, located near Clive in east-central Alberta, has been producing oil since the mid-1950s and has already been water-flooded, which is another proven and widely used EOR method. Using CO2 for enhanced recovery has 50 years of history in North America, but CO2 is relatively underutilized in Canada.
“Using CO2 as an EOR technique is common in the U.S., especially Texas,” says Blair Eddy, COO and VP, engineering and operations with Enhance Energy. “But there are only a handful of CO2-flood projects north of the border, including one at Weyburn, Saskatchewan and another at Joffre, Alberta. Although Alberta has many reservoirs with the right geological characteristics to support CO2 injection, the issue is finding the right kind of CO2.”
Not all carbon dioxide is created equal. Most CO2 is produced as a result of combustion — for example, burning natural gas to create the steam needed for bitumen extraction in the oil sands, or burning coal for electricity generation. Post-combustion CO2 contains compounds and impurities that would have to be scrubbed (removed by heat, chemistry or both) to produce a cleaner gas — with associated costs and, ironically, more emissions.
“We require a relatively pure gas stream that’s water-free and at least 95 per cent CO2,” says Eddy. “We also need a long-term, reliable supply at volumes large enough to meet our needs for EOR.”
Further, the injection process does not involve fracturing the reservoir rock. And even over many years of injecting CO2, the project will inject at pressures lower than the reservoir’s original pressure, so there’s no concern about induced seismicity. Enhance Energy’s approvals from the Alberta Energy Regulatory ensure the integrity of the reservoir – its ability to trap and hold CO2 will not be compromised during this operation.
At the source, CO2 is captured and compressed to create a dense-phase gas, which has properties similar to a liquid but flows like a gas. It can then be transported by pipeline and injected into the Clive reservoir. The CO2 retains this density within the reservoir as it pushes and flushes “stuck” oil from tiny pores and pockets in the rock. Any CO2 produced along with the oil is re-injected.
Enhance Energy has sourced CO2 from two facilities in the Heartland region of Alberta (northeast of Edmonton) that produce the high-quality CO2 needed: the Sturgeon Refinery (the world’s only refinery designed to produce EOR-quality CO2) and Nutrien’s Redwater fertilizer plant. The next challenge: transport the CO2 to the injection site some 240 kilometres to the south.
Getting CO2 from A to B
Enter the Alberta Carbon Trunk Line (ACTL) pipeline, designed to carry CO2.
To build the pipeline, Enhance Energy and partner Wolf Carbon Solutions (pipeline construction and operation) worked closely with landowners along the route and near the injection facility. There was strong acceptance for the project due to several factors – consultation with a commitment to utilize existing infrastructure such as roads to the extent possible, and understanding of the economic and environmental benefits to the local communities and Alberta as a whole. The ACTL project has strong potential for economic revitalization of Central Alberta.
Enhance Energy is also working closely with the Alberta Energy Regulator (AER) in a collaborative approach to education, information sharing and problem resolution. As a result, the project has received all the necessary approvals. Enhance Energy anticipates CO2 injection to begin in the first half of 2020, with oil recovery starting about six months later.
Producing low-carbon oil
“Reservoirs are known to hold hydrocarbons for millions of years,” comments Brendan McGowan, GM, reservoir and development. “Those same geological characteristics will permanently lock the injected CO2 within the Clive reservoir. The carbon capture, utilization and storage (CCUS) side of the project was our initial focus, but more recently we’ve shifted that paradigm to highlight the production of low-cost, low-carbon oil.”
The project’s injection capacity is equivalent to about 20 per cent of all current oil sands emissions. That’s like taking every car in Alberta off the road in terms of reduced emissions. Some 40 to 60 per cent of the oil originally in place in the Clive deposit has already been produced, but CO2 EOR promises to recover an additional 20 to 30 per cent of the remaining oil, extending the field’s productive life up to 30 years. As new high-quality CO2 sources are identified, Enhance Energy intends to use CO2 EOR on a number of other reservoirs in close proximity to the ACTL.
This will be the largest CCUS project in Canada and the oil produced through CO2 EOR will be among the least carbon-intensive in the world. In addition, the project will provide local jobs and generate royalties and taxes for the provincial and federal governments.
“Using CO2 for EOR is not new, it’s proven and well understood,” says McGowan. “But it hasn’t been done at such a large scale in Alberta before. We think there is over one billion barrels of additional oil could be produced from previously developed reservoirs – oil that would not be recovered without CO2 EOR.
Eddy concludes, “In a world that will need oil for generations to come, our industry is innovating to keep reducing emissions per barrel. We expect oil produced from this project will have 60 per cent lower emissions than conventionally produced oil. Plus we’re injecting and permanently storing CO2 from large emissions sources. It’s a win on every level.”