CO (sub 2) injection monitoring using transient electromagnetic in ground-borehole configuration
Using geophysical methods, specifically transient electromagnetic (TEM), for CO (sub 2) monitoring is an effective way to detect CO (sub 2) diffusion. In this work, a multi-scale finite-difference time-domain (FDTD) algorithm was established to monitor CO (sub 2) by defining new iterative relations and approximating boundary conditions, which achieves unification in the time and space domain. The response curve characteristics of different forms of CO (sub 2) were acquired by changing the receiver's depth and position, CO (sub 2) resistivity, scale, and injection stage. Different models considering a planar, tilted, and large-scale CO (sub 2) bodies, which were established to test the capacity of TEM monitoring for CO (sub 2) . The TEM response of injected CO (sub 2) bodies had obvious characteristics and the response curve had distinguishable differences from background. This phenomenon could provide reference models for real TEM CO (sub 2) monitoring.