There are four main geologic storage targets for CCUS including: saline aquifers, unmineable coal seams, enhanced oil recovery schemes, and depleted gas reservoirs. Saline aquifers continue to receive the most attention due to their large theoretical storage capacities. EOR schemes have been operating for many years in a process where CO2 is injected into the reservoir in order to increase efficiency of oil production. However, much of the injected CO2 to date has been produced from nearby high-CO2 reservoirs and CCUS related activities would need to source transport the CO2 from anthropogenic sources in order to qualify as a sequestration scheme. Depleted gas reservoirs have yet to receive regulatory approval for CCUS in Canada although early work indicates suitability of these reservoirs. Unmineable coal seams have received comparatively little attention due to small capacities compared to other options.

  1. Saline Aquifers
  2. Injection into deep unmineable coal seams or enhanced coal bed methane (ECBM)
  3. Use of CO2 in enhanced oil recovery projects
  4. Depleted oil and gas reservoirs