The propagation of
electromagnetic waves in the annular region of oil wells was studied. The
present study aims to analyse the propagation attenuation along the well, as
well as the input impedance determined by a source placed near the wellhead. A
coaxial waveguide model was adopted with heterogeneous dielectrics and losses.
First, a wave equation solution for the waveguide is presented, assuming a
homogeneous medium with losses, by solving the equation in cylindrical
coordinates using the vector potential technique. An uncertainty analysis model
is then developed to model the heterogeneous characteristics of the medium.
 P. A. Patil, et al., “Experimental Study of Electrical Properties of Oil-Based Mud in the Frequency Range from 1 to 100 MHz,” SPE Drilling and Completion, Vol. 25, No. 3, 2010, pp. 380-390. doi:10.2118/118802-PA