EGU22-9292, updated on 28 Mar 2022
https://doi.org/10.5194/egusphere-egu22-9292
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

The real potential of fractured aquifers for CO2 storage

Giampaolo Proietti1, Valentina Romano1, Rajesh Pawar2, and Sabina Bigi1
Giampaolo Proietti et al.
  • 1"La Sapienza" University, Faculty of Mathematical, Physical and Natural Sciences, Earth Sciences Department, Rome, Italy (giampaolo.proietti@uniroma1.it)
  • 2Computational Earth Science, Earth & Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA

The CCS (Carbon Capture & Storage) process involves the capture of CO2 produced by energy production plants, cement factories and refineries, transport to storage sites and injection into deep geological structures with physical and chemical characteristics suitable for long-term confinement. This technology can significantly assess the containment of CO2 emissions into the atmosphere, with an estimated reduction between 12% and 14%. One of the most important phases in which the role of the geoscientist is necessary is the screening of the structures with the suitable geological characteristics for CO2 trapping and the estimation of the injectable mass.

Storage capacity estimates are usually approximate and are based on the average geometric and physical values of the geological formations. Furthermore, not knowing in detail the heterogeneity and complexity of geological structures, many storage efficiency scenarios are presented, which consequently propose very different values. Fractured rocks are one of the largest resources on the earth's surface, and host many of the most important reserves of water, oil and natural gas, and can also be exploited for the storage of gas or carbon dioxide. Determining the dynamic behaviour of fluids within a fractured rock mass is a necessary step in the characterization and definition of a potential site for CO2 injection.

In this work a Discrete Fracture Network (DFN) approach is used to quantify the efficiency of fracture systems to the fluid transport, quantifying the mass of supercritical CO2 injectable in a volume of rock with different fracture intensity in a purely discrete approach, with the utilization of dfnWorks and FEHM software. Using multi-phase reservoir simulations of CO2 injection, we determine the efficiency and storage capacity of fractured rocks. The main result this approach is the introduction of the Efr index which quantifies the efficiency of fracture systems for supercritical CO2 injection. This index allows, starting only from the fracture intensity data and using the equations proposed in the literature for the calculation of the storage capacity, to obtain an immediate and reliable estimate of the volume of the aquifers, which consider the efficiency of fractured aquifers to the fluid flow.

How to cite: Proietti, G., Romano, V., Pawar, R., and Bigi, S.: The real potential of fractured aquifers for CO2 storage, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9292, https://doi.org/10.5194/egusphere-egu22-9292, 2022.