Snohvit: The history of injecting and storing 1 Mt CO2 in the fluvial Tubaen Fm

The Snohvit CO2 injection into the Tubaen Formation ended in April 2011. This per summarizes the Statoil experiences from the injection regarding operational aspects, monitoring and simulation of the CO2 flow in the reservoir. The use of down-hole pressure measurement, in combination with repeated surface seismic data, improved the understanding of the injection process. Detailed interpretation of fall-off pressures in combination with good and updated reservoir models and thorough investigations into the rock mechanical strength of the reservoir rock lead eventually to the abandonment of the original injection reservoir. The storage capacity of the Tubaen Formation is not reached, but the well and the near well reservoir could not receive the necessary volume rate. A PLT-log was run during abandonment confirming pressures and flow scenario and thereby the previous interpretations. The CO2 injection at Snohvit continues at normal levels in a fallback reservoir. No CO2 has been or will be vented to the atmosphere. (C) 2013 The Authors. Published by Elsevier Ltd. Open access under CC BY-NC-ND license. Selection and/or peer-review under responsibility of GHGT