The comparative benefits of storage in depleted and deep saline reservoirs for CCS

Both depleted oil and gas reservoirs and deep saline reservoirs offer potentially viable CO₂ storage solutions. We'll examine some of the pros and cons of each.

Andy Kirchin, Director Subsurface Low-Carbon Solutions

There is little serious disagreement that without carbon capture, utilisation and storage (CCUS), the global targets for Net-Zero and limiting warming to 1.5^oC by 2050 are impossible to meet. The Energy Information Administration (EIA) estimates that 650 million tonnes (Mt) of CO₂ storage capacity will be required per year by 2030 to be in line with their sustainable development scenario, with capacity reaching 5,266 Mt/yr by 2050 and 9,533 Mt/yr by 2070 (EIA, 2020). As the technology and infrastructure to capture CO₂ become more economically viable, the availability of places to permanently store it becomes crucial.

Geological storage options

Both depleted oil and gas reservoirs and deep saline reservoirs offer potentially viable CO₂ storage solutions, primarily for complementary reasons. The likely performance and, therefore, the attractiveness of these two types of geological storage will be influenced principally by their containment potential, both in terms of volume and ability to 'seal' away the CO₂ for considerable periods of time, and their injectivity potential. Both of these principal controls on the attractiveness of any given storage site are subject to different degrees of uncertainty depending...