Electromagnetic Modeling of Thin Wire with Multilayered Coating in Layered Media

An efficient numerical method is presented to simulate the thin wire structures with multilayered coating in the horizontally layered media. A target application can be underground wireless communication using electromagnetic telemetry (EMT), which consists of a long metal drill string treated as a thin wire and a gap near the drill bit as the source. The numerical scheme uses the electric field integral equation (EFIE) and layered media Green's function (LMGF) to model the electromagnetic interaction of the drill string and layered media. The effect of the multilayered coating (drilling fluid, cement, and casings in borehole) is modeled using the equivalence principle without increasing the number of unknowns. Only the induced current on the thin wire is discretized as the unknowns. Numerical results are presented to demonstrate the efficacy of the proposed method.