Parametric Controls on Dynamic CO2 Storage Capacity in a Saline Aquifer: The Lopín Structure Case Study (Ebro Basin, NE Spain)

This is the authors' abstract. We don't add key points for this paper.

Pressure-limited dynamic capacity in the Lopín structure is controlled primarily by reservoir transmissibility rather than by static pore volume. This study applies a MATLAB/MRST vertical-equilibrium (VE) workflow to the Lopín horst, a deep Triassic Buntsandstein aquifer in the Ebro Basin, NE Spain, and evaluates the sensitivity of the results to seven petrophysical, fluid, and operational parameters using a one-at-a-time sensitivity design (35 sensitivity cases plus one base case). Across the tested range, horizontal permeability produced the largest variation in maximum injectable CO2 mass, from 4.67 to 16.25 Mt (range 11.59 Mt), followed by the adopted BHP threshold (range 5.33 Mt) and CO2 density (range 4.74 Mt). Porosity and brine compressibility had only minor effects, whereas injection rate and residual CO2 saturation did not change the BHP-limited capacity under the adopted capacity-search formulation. The base-case operational BHP limit was 28.5 MPa, selected below the site-specific allowable- and estimated fracture-pressure thresholds reported for Lopín. These results show that pressure dissipation, hydraulic transmissibility, and the explicit choice of operational pressure criterion are the dominant controls on dynamic CO2 storage capacity in this fault-bounded saline aquifer.