Publication Date:
2024-05-09
Description:
CO2 sequestration in geological formations requires specific conditions to safely
store this greenhouse gas underground. Different geological reservoirs can be used for this
purpose, although saline aquifers are one of the most promising targets due to both their
worldwide availability and storing capacity. Nevertheless, geochemical processes and fluid
flow properties are to be assessed pre-, during, and post-injection of CO2. Theoretical calculations
carried out by numerical geochemical modeling play an important role to understand
the fate of CO2 and to investigate short-to-long-term consequences of CO2 storage into deep
saline reservoirs. In this paper, the injection of CO2 in a deep structure located offshore in the
Tyrrhenian Sea (central Italy) was simulated. The results of a methodological approach for
evaluating the impact that CO2 has in a saline aquifer hosted in Mesozoic limestone formations
were discussed. Seismic reflection data were used to develop a reliable 3D geological
model, while 3D simulations of reactive transport were performed via the TOUGHREACT
code. The simulation model covered an area of 〉100 km2 and a vertical cross-section of
〉3 km, including the trapping structure. Two simulations, at different scales, were carried
out to depict the local complex geological system and to assess: (i) the geochemical evolution
at the reservoir–caprock interface over a short time interval, (ii) the permeability variations
close to the CO2 plume front, and (iii) the CO2 path from the injection well throughout the
geological structure. One of the most important results achieved in this study was the formation
of a geochemical barrier as CO2-rich acidic waters flowed into the limestone reservoir.
Description:
Published
Description:
107-143
Description:
5A. Energia e georisorse
Description:
JCR Journal
Description:
restricted
Keywords:
CO2 geological storage
;
Reactive transport modeling
;
Deep saline aquifers
;
Geochemical barriers
;
Permeability feedback
;
03. Hydrosphere::03.04. Chemical and biological::03.04.05. Gases
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
