학술논문
Characterization of the Mechanisms Controlling the Permeability Changes of Fractured Cements Flowed Through by CO2 -Rich Brine.
Document Type
Article
Author
Source
Subject
*PERMEABILITY
*CEMENT fractures
*CARBON dioxide
*SALT
*LEAKAGE
*CARBONATION (Chemistry)
*SEQUESTRATION (Chemistry)
*AMORPHOUS silicon
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Language
ISSN
0013-936X
Abstract
Experiments were conducted to assess the potential impact of fractured well-cement degradation on leakage rate. Permeability was monitored while CO2-enriched reservoir-equilibrated brine was flowed at constant rate through a single fracture in a class G cement core under conditions mimicking geologic sequestration environments (temperature 60 °C, pressure 10 MPa). The results demonstrate that, at least for the conditions used in the experiment, an initial leakage in a 42 μm aperture fracture (permeability = 1.5 × 10-10 m²) can be self-mitigated due to the decrease of the fracture hydraulic aperture after about 15 h. This decrease results from the development of continuous highly hydrated amorphous Si-rich alteration products at the edge of the fracture and the dense carbonation of the bulk cement that mitigate the penetration of the alteration front. [ABSTRACT FROM AUTHOR]