In t
he pap
er w
e s
har
e our op
erational
exp
eri
enc
e gain
ed from t
hr
ee sit
es: Sl
eipn
er (14 y
ears of inj
ection), In Sala
h (6 y
ears) and Sn
xf8;
hvit (2 y
ears). Tog
et
her, t
hes
e t
hr
ee sit
es
hav
e dispos
ed 16 Mt of CO
2 by 2010.
In highly variable reservoirs, with permeability ranging from a few milliDarcy to more than one Darcy, single wells have injected several hundred Kt of CO2 per year. In the reservoirs, the actual CO2 plume development has been strongly controlled by geological factors that we learned about during injection. Geophysical monitoring methods (especially seismic, gravity, and satellite data) have, at each site, revealed some of these unpredicted geological factors. Thus monitoring methods are as valuable for reservoir characterisation as they are for monitoring fluid saturation and pressure changes.
Current scientific debates that address CO2 storage capacity mainly focus on the utilization of the pore space (efficiency) and the rate of pressure dissipation in response to injection (pressure limits). We add to this that detailed CO2 site characterisation and monitoring is needed to prove significant practical CO2 storage capacity–on a case by case basis. As this specific site experience and knowledge develops more general conclusions on storage capacity, injectivity and efficiency may be possible.