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The impacts of reactive transport on caprock integrity

Speaker: Hang Deng, Graduate Student
Series: EEWR Brown Bag Seminars
Location: Engineering Quad E225
Date/Time: Friday, November 9, 2012, 12:00 p.m. - 1:00 p.m.

Abstract:

Geological storage of CO2 is one of the most promising options for carbon mitigation, but its application relies heavily on caprock integrity, which is controlled by not only the hydrodynamic properties, but also the geochemical characteristics of the caprocks (e.g. mineralogy) and their interplay with CO2-acidified brine.

Fractures in caprocks, whether preexisting or newly created due to CO2 injection, may serve as leakage pathways for the injected CO2. Hydrodynamic properties of these fractures, e.g. transmissivity and permeability, are primarily controlled by fracture geometries, which are subject to alteration caused by reactions between CO2- acidified brine and minerals along the fracture faces.

In this study, x-ray Computed Tomography (xCT) scans from a previous experiment and Computational Fluid Dynamics (CFD)simulations were used to quantify changes in fracture hydrodynamic properties due to geometrical alterations (extensive dissolution, roughness increase, and creation of degraded zones) initiated by
geochemical reactions.