摘要

A set of compact and stable formulations is presented to calculate the response of logging tools employing tilted-coil antennas in anisotropic concentrically cylindrical multilayered formation. The presented formulations can be used to investigate the effect of mandrel, borehole, and invasion. Our formulations are different from previous ones in three aspects. First, the tool mandrel can be cylindrically multilayered, and electrical parameters of each layer are arbitrary. That is to say, the mandrel is not limited to being perfectly metallic. Second, the formation can be either anisotropic or isotropic. Finally, the propagation of electromagnetic wave in an inhomogeneous cylindrical medium is described by the generalized reflection and transmission coefficients without the numerical overflow issue. Numerical results in comparison with those from other approaches have demonstrated the validity and stability of our new formulations.