From Bureau of Economic Geology, The
University of Texas at Austin (www.beg.utexas.edu).
For more information, please contact the author.
Bureau Seminar, December 11, 2009
Monitoring the behavior of CO2 in shallow environments: evidence from one natural and two industrial carbon-storage analogue sites
Link to streaming video: available 12.11.2009 at 8:25am
Bureau of Economic Geology
Carbon capture and storage (CCS) is a method of mitigating global warming by capturing industrial CO2 emissions and storing them in deep geologic formations. Methodologies and protocols for shallow monitoring at future CCS sites are currently in development and include techniques that target shallow potable aquifers that require protection and the shallow biosphere which includes vadose-zone and surface environments.
The desire to create a standard monitoring protocol that can be widely applied to CCS sites has lead to oversimplification in the near-surface environment, both in aquifers and in the vadose zone. Shallow environments are dynamic over space and time because they are easily affected by fluctuating factors such as land use, seasonal changes, and weather patterns. In addition, CO2 is highly reactive in the subsurface and will cycle between organic and inorganic components via biotic and abiotic processes. CO2 production and consumption, can create large variability in natural background CO2 concentrations which, when taken out of context, could lead to erroneous interpretations. Errors could be either at sites where CO2 leakage has occurred but is not detectable or at sites where non-injection induced changes are mistakenly assumed to indicate leakage.
This presentation focuses on the integrated lessons learned from studying CO2 behavior in the natural vadose-zone of a Texas High Plains playa lake and how these lessons are transferring to groundwater and soil-gas studies at two CO2-EOR oilfield sites currently being studied.