Snøhvit: The History of Injecting and Storing 1 Mt CO2 in the Fluvial Tubåen Fm

Abstract

The Snøhvit CO2 injection into the Tubåen Formation ended in April 2011. This paper 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 Tubåen 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 Snøhvit continues at normal levels in a fallback reservoir. No CO2 has been or will be vented to the atmosphere.