A Difference Potential Method for Induction Sondes

The response of a general induction sonde in a heterogeneous formation is computed using a difference potential technique. This difference potential method effectively transforms the source coil singularities into a continuum of finite sources distributed throughout the formation. The resulting equations are solved via finite-difference techniques. The apparent conductivity responses are corroborated by the solutions of an integral equation formulation for two invaded thin bed examples and a homogeneous formation example.