Storage capacity of CO2 in geological media in sedimentary basins with application to the Alberta basin

Sequestration of CO2 in geological media is a mid-to-long term solution to mitigating greenhouse gas effects on climate change. It is based on deep injection of CO2 in sedimentary basins, which are naturally associated with fossil energy resources whose exploitation leads itself to CO2 production and emission to the atmosphere. Basically there are five ways for CO2 sequestration in geological media: use in enhanced oil recovery, injection in disused oil and gas reservoirs, replacement of methane by CO2 in deep coal beds, injection into deep saline aquifers, and storage in salt caverns. However, not all sedimentary basins are suitable for CO2 sequestration because of issues related to tectonism, geology and flow of formation waters, which all ultimately lead to issues of integrity, safety and duration of CO2 sequestration. The most important elements in assessing the viability of, and improving the estimates of CO2 sequestration in sedimentary basins are the tectonic characteristics of the basin; the existence, storage capacity and integrity of the storage media; the hydrodynamic regime of formation waters; and the basin maturity. Coupling this assessment with the analysis of surface CO2 sources, capture, transport and facilities for injection should lead to the selection of prime candidates for CO2 sequestration. From these points of view, the Alberta basin meets all the criteria for CO2 sequestration in geological media. The basin is tectonically stable; has abundant oil and gas resources and major coal and tar sands deposits; has deep regional saline aquifers with a favorable flow regime: and deep, extensive. thick salt layers. Major CO2 point sources are coal-based power plants and well developed energy and petrochemical industries. CO2 is already used in enhanced oil recovery and is injected as acid gas in several depleted reservoirs and deep saline aquifers. This makes the Alberta basin a prime candidate for CO2 sequestration in geological media.