A. Executive Summary We propose a new, integrated approach for monitoring, verification, and accounting of CO2 sequestered in deep geologic repositories. Our approach includes:
1.High precision space geodesy (GPS and InSAR) to measure subtle surfacedisplacements associated with pressure/volume changes at depth due to pumping of CO2
2. Analytical and numerical (finite element) modeling, to relate deformation at the surface to pressure/volume changes at depth
3. New, state of the art algorithms for retrieval of Vp, Vs and attenuation from seismic data, to monitor fluid motions and porosity changes
4. Geochemical modeling and sampling, to assess the fate of sequestered gas or fluid, separate the effects of formation of new reaction products (generally a desired outcome, fixing CO2 in solid form) from leakage or loss of gas or fluid from the reservoir (an undesirable outcome), and to directly measure leakages should they occur. If successful, our proposed methodology can be implemented at relatively low cost at most proposed sequestration sites, requiring only the installation of a sparse network of GPS, seismic and geochemical stations, and low cost commercial satellite imagery.