Geological Storage of CO2: a State-Of-The-Art of Injection Processes and Technologies

Abstract : An overview is given of the well technology needed for CO2 injection and the near wellbore processes: - Well materials and abandonment procedures must be designed in order to avoid CO2 leakage through the well to ensure long-term safety of the CO2 storage. Furthermore, various mechanical effects can affect the well and the injection process. Geomechanical models are required to identify the optimal injection pressure that will damage neither the well nor the reservoir. - The near wellbore region is subjected to chemical phenomena due to CO2 injection which may affect drastically the injectivity. These dissolution/reprecipitation mechanisms are very case-dependant and need more theoretical and experimental investigation in order to control the injectivity of a CO2 injection well, which is crucial because huge amounts of CO2 will have to be injected.