A Robust Mode-Matching Algorithm for the Analysis of Triaxial Well-Logging Tools in Anisotropic Geophysical Formations

作者：Rosa Guilherme S^*; Bergmann Jose R; Teixeira Fernando L

来源：IEEE Transactions on Geoscience and Remote Sensing, 2017, 55(5): 2534-2545.

DOI：10.1109/TGRS.2016.2646839

• Anisotropic media
• mode-matching methods
• multilayered media

In this paper, a new pseudoanalytical axial mode-matching formulation is introduced to provide a flexible technique for analyzing direction well-logging tools in anisotropic formations. The presented technique does not rely on spatial discretization as former well-known methods. In this problem, a number of coil antennas with arbitrary relative tilt angle with respect to the symmetry axis are used to radiate electromagnetic fields in a cylindrically layered medium with both axial and radial stratifications, composed of a metallic mandrel, a borehole, and a surrounding layered earth formation. This configuration corresponds to that of triaxial well-logging tools used for oil and gas exploration. Our approach combines closed-form solutions of Maxwell's equations for uniaxially anisotropic media in cylindrical coordinates with the generalized scattering matrix (GSM) at each axial discontinuity based on the mode-matching technique. The electromagnetic field from the tilted-coil source is represented by a set of modal coefficients that, after computation using GSM matrices, are used to extract the transimpedances of the well-logging tool.

• 出版日期2017-5