Electrokinetic and Poroelastic Characterization of Porous Media : Application to CO2 storage monitoring

Abstract

Monitoring the properties of a CO2 storage reservoir is important for two main reasons: firstly, to verify that the injected CO2 is safely contained in the reservoir rock as planned, and secondly, to provide data which can be used to update the existing reservoir models and support eventual mitigation measures in case of deviation from the CO2 storage plan. Reliable quantitative monitoring of reservoir rocks and pore-filling fluids remains a challenging task in geophysical prospecting. Typically, geophysical electrical and seismic surveys are used to predict reservoir properties. Electrical properties of rocks are strongly controlled by the chemistry of the fluids that fill the pore space. Thus, electrical surveys can provide accurate estimates of pore-filling fluid composition and porosity of reservoir rock. Seismic methods are particularly sensitive to elastic heterogeneities in the subsurface. Elastic properties of reservoir rocks can be extracted from recorded seismic data. Potentially, the simultaneous use of electrical and seismic geophysical surveys can reduce the uncertainty in the quantitative characterization of reservoir rocks. In this thesis, theoretical and experimental research is conducted to show the feasibility of such an integrated approach for a CO2 storage reservoir.