Journal of Canadian Petroleum Technology, Vol.43, No.11, 49-55, 2004
Sequestration of CO2 in salt caverns
Permanent storage of CO2 in dissolved salt caverns is one of the geological options for reducing anthropogenic greenhouse gas emissions into the atmosphere. Alberta is singularly; well endowed with suitable salt deposits. Of these, the Lotsberg Salt of cast central Alberta is the best of the three major salt-bearing zones, and is geographically close to present and future; sources of CO2 associated with fossil fuel development projects in Alberta. The characteristics of the Lotsberg Salt and overlying strata are presented in the context of the long-term future of stored CO2. There are a number of features that indicate a high level of security against leakage and migration of gas back to the biosphere. A procedure for the creation, testing, and filling of a salt cavern is presented. A critical requirement was to achieve a reasonable long-term prediction of the behaviour of the cavern during slow: closure, while taking into account the pressure and volume behaviour of the gas within the cavern. This was achieved with a semi-analytical model that predicts long-term pressures and, volume changes. There appear to be no technical obstacles or undue risks; identified that would militate against the use of salt caverns for permanent CO2 sequestration. It is an option that can be seriously considered in Alberta, or in other geographical locations where the geological conditions are suitable.