Overview of the geochemical modeling on CO2 capture & storage in Italian feasibility studies

Davos, Svizzera

CO2 Capture & Storage in saline aquifers is presently one
of the most promising technologies for reducing
anthropogenic emissions of CO2. In these sites the short-longterm
consequences of CO2 storage into a deep reservoir can be
predicted by numerical modelling of geochemical processes.
Unfortunately a common problem working with off-shore
closed wells, where only the well-log information are
available, is to obtain physico-chemical data (e.g.
petrophysical and mineralogical) needed to reliable numerical
simulations. Available site-specific data generally include only
basic physical parameters such as temperature, pressure, and
salinity of the formation waters.
In this study we present a methodological procedure that
allows to estimate and integrate lacking information to
geochemical modelling of deep reservoirs such as: i) bulk and
modal mineralogical composition, ii) porosity and
permeability of the rock obtained from heat flow
measurements and temperature, iii) chemical composition of
formation waters (at reservoir conditions) prior of CO2
injection starting from sampling of analogue outcropping rock
formations.
The data sets in this way reconstructed constitute the base
of geochemical simulations applied on some deep-seated
Italian carbonatic and sandy saline aquifers potentially suitable
for geological CO2 storage.
Numerical simulations of reactive transport has been
performed by using the reactive transport code
TOUGHREACT via pressure corrections to the default
thermodynamic database to obtain a more realistic modelling.
Preliminary results of geochemical trapping (solubility and
mineral trapping) potentiality and cap-rock stability as
strategic need for some feasibility studies near to be started in
Italy are here presented and discussed.