Feasibility of Using Joint Seismic and CSEM for Monitoring CO2 Storage

We investigate the sensitivity of the controlled source electromagnetic (CSEM) soundings to buried thin resistive layers that could represent CO2 storage reservoirs. This work is a feasibility study which first investigates the sensitivities of 3D CSEM data to a realistic CO2 storage, and then analyses the use of CSEM data for making estimates of the post-injection build-up of CO2 layers in the subsurface. The difference whether CO2 is concentrated in a single plume or accumulated in closely packed multiple plumes in a 3D CO2 reservoir is modeled and examined to determine the general effects these cases have on the data. While CSEM is shown to be very sensitive to injected volume of CO2, in the meantime, it has a limited structural resolution, which can be obtained from seismic. As an example of optimal utilizing the potential of both datasets, a feasibility test of using the time-lapse monitoring is presented by a 1D joint seismic and CSEM inversion with a synthetic data resulted from a water saturated sedimentary storage site.