Modification of Fracture Hydraulic Properties by CO2-Acidified Brine Flow
- Type: Conference Presentation
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In this study, we aim to quantify the changes in fracture permeability and flow velocity fields caused by exposing a fractured carbonate caprock sample to CO2-acidified brine flow. Before and after a flow-through experiment, X-ray computed micro-tomography scans were taken. The images were segmented and processed to reconstruct the initial and final fracture geometries. 1-D empirical equation, 2-D steady state flow model, and 3-D computational fluid dynamics (CFD) simulation were applied on the reconstructed fracture geometries to estimate the intrinsic permeabilities prior to and after the experiment. The capabilities of the 1-D empirical equation, 2-D steady state flow model and 3-D CFD simulation in quantitatively capturing the permeability evolution are also examined. Furthermore, comparing the detailed pre- and post- fluid velocity field provides important insights on the direction of local geochemical reactions. The simulation results serve to deepen our understandings of the modification of fracture hydraulic properties by CO2-acidified brine flow, and hence to improve our predictive capability on evolution of caprock integrity and leakage risks.