Geochemical controls on fracture evolution in carbon sequestration

J. P. Fitts, B. R. Ellis, H. Deng, Catherine Anne Peters

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations


Stored supercritical CO2 will acidify native brines in deep saline aquifers and promote mineral dissolution within the storage formation resulting in varying degrees of calcite saturation. Injection overpressure will force these reactive brines into existing and induced fractures in overlying caprock formations. We present examples from our experimental efforts to understand how these fluids might alter fracture geometry and leakage pathway permeability, with the ultimate goal of predicting caprock integrity. We use mineral-specific imaging analysis to correlate changes in fracture geometry with spatial maps of dissolution and precipitation. Synchrotron-based x-ray spectroscopy and diffraction imaging of thin section sub-samples of the cores from the flow-thru experiments are used to connect mineral-specific dissolution and precipitation processes with the geometric changes in fracture aperture observed with CT images. Results of μXRF, μXANES and μXRD analyses reveal that preferential calcite dissolution and the spatial distribution of relatively insoluble dolomite and silicate minerals produced the non-uniform aperture widening. These results clearly point to the need for predictive models of caprock integrity to consider coupled geochemical processes, mineralogical characterizations, and geometric alterations of flow paths.

Original languageEnglish (US)
Title of host publication46th US Rock Mechanics / Geomechanics Symposium 2012
Number of pages6
StatePublished - 2012
Event46th US Rock Mechanics / Geomechanics Symposium 2012 - Chicago, IL, United States
Duration: Jun 24 2012Jun 27 2012

Publication series

Name46th US Rock Mechanics / Geomechanics Symposium 2012


Other46th US Rock Mechanics / Geomechanics Symposium 2012
Country/TerritoryUnited States
CityChicago, IL

All Science Journal Classification (ASJC) codes

  • Geotechnical Engineering and Engineering Geology


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