Many different gases are contained naturally in underground structures, and commercial geological storage of gases including carbon dioxide, methane and hydrogen has been practised under regulated conditions over many years. The principal commercial options considered by the Carbon Capture and Storage Association for storing CO2 are saline aquifers and hydrocarbon reservoirs.
Oil and gas reservoirs – additional benefits
Partially depleted oil and gas reservoirs are attractive options for storing CO2 as their geology is generally well known and they have a very long proven track record of containment of gases. In the case of oil reservoirs there is a case to utilise the solvent properties and high pressure of CO2 to assist in recovering more oil from the reservoir. This technique of enhanced oil recovery (EOR) has been applied successfully in the USA for over 30 years and has resulted in commercial extraction of about one third more oil than without enhancement.
Saline aquifers – vast potential
Saline aquifers offer a great deal more potential than hydrocarbon reservoirs in terms of total storage capacity. Estimates vary because not all known geological structures have not been comprehensively studied, but many estimates suggest there exists capacity to store the entire world’s CO2 production for several centuries.
Business opportunities in storage
The operation of geological stores is a business that will be the subject of government/industry licensing arrangements similar to those practiced in the mining and oil and gas industries. Geological storage of CO2 is a long-term business opportunity that can best be addressed by substantial organisations that specialise in geology and geophysics.
2008 CCSA © | Last Updated: Jan 2008
