Fast forward modeling and data processing of 3D induction logging tool in layered anisotropic formation

Using generalized reflection coefficients, we deduced a complete form of solution for the electromagnetic field in layered anisotropic formations. Those generalized reflection coefficients can be evaluated with recursion formula for each electromagnetic wave mode. A fast forward modeling is achieved through the Fast Hankel Transformation (FHT) method. The responses of a 3D induction logging tool are determined by the horizontal conductivity, the vertical conductivity, the relative dip of the formation and the azimuth angle of the tool, and a single component of the logging curve can't meet the need of data interpretation. Gaining insight into the response characteristics of the measurement components of a 3D induction tool, we developed a quick-look interpretation method by combining the measurement components in different ways. The processing results of numerically simulated data have shown the fact that the combination of the cross-components accurately outlines the boundary location and qualitatively recognize anisotropic layers, while the combination of the primary components enhances resolution and reduces nonlinearity relating to electrical parameters.