Oil sands reservoirs may experience “thief zones” — areas above or below the oil zones that “steal” energy and pressure. Thief zones result in a need for increased steam injection in order to maintain pressure and temperature within the reservoir during oil production, which increases greenhouse gas (GHG) emissions. An ongoing pilot project tested the effectiveness of co-injecting a non-condensable gas (NCG), such as methane, with steam to create an insulating blanket that potentially reduces thermal and pressure losses in the steam chamber.

“In SAGD (Steam-Assisted Gravity Drainage), the oil production process becomes less efficient as the reservoir becomes depleted. Since more steam is needed to fill the space vacated by the already-extracted resource, there is less direct contact between the steam and the bitumen. Additional energy is required to produce more steam, which increases GHG emissions and costs,” said project lead Julian Ortiz. “We hope that NCG co-injection provides a solution to this inefficiency.”

The concept of using NCG co-injection technology to reduce GHG emissions while reducing operating costs was first examined by our Canada Business Unit in 2017, and initial results were encouraging. We recently received $2.5 million from Emissions Reduction Alberta, a government organization that helps accelerate commercial development by co-funding innovative technology projects, to continue work using NCG co-injection technology on 12 additional SAGD well pairs. The funds will augment the company's $4 million thief zone management pilot at Surmont 2, a 50/50 joint venture with Total E&P Canada that is operated by ConocoPhillips. The goal is to validate the technology on a commercial scale by building on past work in NCG co-injection and expanding the application to the full lifecycle of a well. NCG co-injection at the proposed scale could reduce GHG emissions by up to 15 percent in reservoirs affected by thief zones and operating costs could be reduced by up to 20 percent at SAGD facilities where the technology is utilized.

Although still early in testing, the steam-to-oil ratio has been reduced by over 20 percent in the pilot area since NCG co-injection started April 2018.

“We have been working to develop and share technologies that will lower emissions and make the Canadian oil sands more competitive globally. If we can significantly reduce the amount of steam required, the impact on GHG emissions in Alberta will be massive,” Ortiz noted.