Выпуск: 9 , Том: 45 , Год издания: 2009

In applied studies on electromagnetic well-logging and electric prospecting, a medium is supposed to be either isotropic or with conventional anisotropy of conductivity. However, in the meantime, there is a clear hint that a medium may exhibit even biaxial anisotropy; i.e., the resistances along all three directions X, and Y, Z are different. Based on the analytical solution by the method of separation of variables, the paper considers an algorithm for the calculation of the electromagnetic field in a layered medium with biaxial conductivity anisotropy involving an arbitrary direction of horizontal conductivities in each layer. In this case, the theoretical solution and the algorithm display substantial peculiarities, and the numerical implementation involves many complexities. These problems were examined and solved mainly due to the constant comparison with the calculations carried by the finite element method and their analysis. Programs for the calculation of electromagnetic fields in the frequency and time domains were developed, and results of geoelectric interest were obtained. For example, the excitement of a horizontally-layered section by a magnetic dipole produces a vertical electric component of the field.