In Salah is a pioneering, industrial-scale CCS operation that has been running in Algeria since 2004. More than three million tonnes of CO2 have already been stored in a deep saline formation almost two kilometres below the Earth’s surface.
The CO2 is stored as part of a natural gas production process, operated by BP, Sonatrach and Statoil, in the central Algerian Ahnet-Timimoun basin. Operational since 2004, the gas field holds an estimated 160 billion cubic metres of gas and has an expected operational life of 20 years.
As the natural gas contains small amounts of CO2, it was necessary to separate out the CO2 to meet purity standards for sale. Rather than vent the CO2, it was decided to invest $100 million to store it geologically. A Joint Industry Project (JIP) was subsequently set up between the original partners BP and Sonatrach — Algeria’s state oil and gas company — and was later joined by Statoil.
CCS project of international importance
In Salah has been recognised by the Carbon Sequestration Leadership Forum as one of the most important CCS initiatives in the world. With more than three million tonnes of CO2 securely stored so far, In Salah counters the misconception that CCS technology is unproven at industrial scale.
CO2 Injection Status
A key feature of any monitoring programme is the ability to use the monitoring data to respond to field performance and operational developments. The In Salah CCS demonstration project has been an important example for understanding the value of various monitoring methods applied. Several Quantified Risk Assessments (QRA) have been conducted during the operational phase, integrating all available data to assess both the storage integrity and effectiveness of the storage complex.
Following the 2010 QRA, the decision was made to reduce CO2 injection pressures in June 2010.
Subsequent analysis of the reservoir, seismic and geomechanical data led to the decision to suspend CO2 injection in June 2011. The future injection strategy is currently under review and the comprehensive site monitoring programme continues.
Ringrose, P. S., Mathieson, A. S., Wright, I. W., Selama, F., Hansen, O., Bissell, R., Saoula, N. &
Midgley, J. 2013. The In Salah CO2 storage project: lessons learned and knowledge transfer.
Energy Procedia, 37, 6226–6236 (GHGT11).