Calculating Electromagnetic Field of Centered Dipole Source in Cylindrical Medium With Modified Reflection and Transmission Coefficients

In this article, the electromagnetic (EM) field excited by the triaxial electrical/magnetic dipole sources is presented in a cylindrical multilayer transverse isotropic (TI) medium. A set of modified generalized reflection and transmission coefficients is introduced to describe the EM field propagation, which avoids the overflow problem in numerical computation. Those coefficients consist of Bessel and Hankel functions with complex argument. The divergent factors of those cylindrical functions are extracted and rearranged in the recursive formulations, which ensure that the field attenuates along its propagating direction. The centered dipole sources are in-deep discussed in our model to simplify previously published formulations and improve the computational efficiency, as there are only up to two harmonics are considered due to axial symmetry. The singularity issue due to the Bessel and Hankel functions with zero argument is also well handled, while the field point is located along the central axis. Those formulations can be widely used for forward modeling for EM well logging. Finally, the radial geometrical factors are simulated and analyzed for ultradeep azimuthal resistivity logging (UARL).